Francisco Areces - Academia.edu (original) (raw)
Papers by Francisco Areces
Revista Brasileira de Medicina do Esporte, 2020
Introduction: This study aimed to measure thickness and cross-sectional area of the Achilles tend... more Introduction: This study aimed to measure thickness and cross-sectional area of the Achilles tendon (AT), and the range of motion of the ankle joint in dorsiflexion of amateur marathon runners compared to non-active people. Objectives: To analyze the relationship between cross-sectional area and thickness of the Achilles tendon in marathon runners and age, anthropometric characteristics (height and body mass), training habits, running experience, marathon performance, and range of motion in the ankle joint. Methods: Achilles tendon thickness and cross-sectional area were measured using ultrasound images of the left leg in 97 male amateur marathon runners (age 42.0 ± 9.6 years; height 175 ± 6 cm; and body mass 73.7 ± 8.6 kg), and 47 controls (39.9 ± 11.6 years; 176 ± 7 cm; 79.6 ± 16.1 kg). Results: Achilles tendon thickness (4.81 ± 0.77 vs. 4.60 ± 0.66 mm; p = 0.01) and cross-sectional area (60.41 ± 14.36 vs. 53.62 ± 9.90 mm2; p < 0.01) were greater in the marathon runners than in...
PLOS ONE, 2020
A common single nucleotide polymorphism in the ACTN3 gene might result in the complete deficiency... more A common single nucleotide polymorphism in the ACTN3 gene might result in the complete deficiency of α-actinin-3 (i.e., XX genotype). It has been found that ACTN3 XX individuals have several traits related to lessened muscle performance. This study aimed to determine the influence, if any, of ACTN3 genotypes on injury incidence of marathoners during the year preceding to participating in a competitive marathon race. Using a cross-sectional experimental design, the type and conditions of sports injuries were documented for one year in a group of 139 marathoners. Injuries were recorded following a consensus statement on injuries in Athletics. Afterward, ACTN3 genotyping was performed, and injury epidemiology was compared among RR, RX, and XX genotypes. The distribution of the RR/RX/XX genotypes was 28.8/42.8/23.5%, respectively. A total of 67 injuries were recorded. The frequency of marathoners that reported any injury during the previous year was not different across the genotypes (55.0/38.8/40.6%, P = 0.241). Although the overall injury incidence was not different among genotypes (2.78/1.65/1.94 injuries/1000 h of running, P = 0.084), the likelihood of suffering an injury was higher in RR than in RX (OR = 1.93: 95%CI = 0.87-4.30), and higher than in XX (OR = 1.79: 0.70-4.58). There was no difference in the conditions, severity, body location, time of year, or leading cause of injury among genotypes. However, XX presented a higher frequency of sudden-onset injuries (P = 0.024), and the OR for muscle-type injuries was 2.0 (0.51-7.79) times higher compared to RR runners. Although XX marathoners did not have a higher overall incidence of injury, the OR in these runners for muscle-type injuries was superior to RR and RX runners. The likelihood of suffering a muscle injury, especially with a sudden-onset, was twice in XX than in RR endurance runners.
Nutrients, 2017
The aim of this study was to determine the effect of caffeine intake on overall basketball perfor... more The aim of this study was to determine the effect of caffeine intake on overall basketball performance in experienced players. A double-blind, placebo-controlled, randomized experimental design was used for this investigation. In two different sessions separated by one week, 20 experienced basketball players ingested 3 mg of caffeine/kg of body mass or a placebo. After 60 min, participants performed 10 repetitions of the following sequence: Abalakov jump, Change-of-Direction and Acceleration Test (CODAT) and two free throws. Later, heart rate, body impacts and game statistics were recorded during a 20-min simulated basketball game. In comparison to the placebo, the ingestion of caffeine increased mean jump height (37.3 ± 6.8 vs. 38.2 ± 7.4 cm; p = 0.012), but did not change mean time in the CODAT test or accuracy in free throws. During the simulated game, caffeine increased the number of body impacts (396 ± 43 vs. 410 ± 41 impacts/min; p < 0.001) without modifying mean or peak heart rate. Caffeine also increased the performance index rating (7.2 ± 8.6 vs. 10.6 ± 7.1; p = 0.037) during the game. Nevertheless, players showed a higher prevalence of insomnia (19.0 vs. 54.4%; p = 0.041) after the game. Three mg of caffeine per kg of body mass could be an effective ergogenic substance to increase physical performance and overall success in experienced basketball players.
Nutrients, 2017
Previous investigations have determined that some individuals have minimal or even ergolytic perf... more Previous investigations have determined that some individuals have minimal or even ergolytic performance effects after caffeine ingestion. The aim of this study was to analyze the influence of the genetic variations of the CYP1A2 gene on the performance enhancement effects of ingesting a moderate dose of caffeine. In a double-blind randomized experimental design, 21 healthy active participants (29.3 ± 7.7 years) ingested 3 mg of caffeine per kg of body mass or a placebo in testing sessions separated by one week. Performance in the 30 s Wingate test, visual attention, and side effects were evaluated. DNA was obtained from whole blood samples and the CYP1A2 polymorphism was analyzed (rs762551). We obtained two groups: AA homozygotes (n = 5) and C-allele carriers (n = 16). Caffeine ingestion increased peak power (682 ± 140 vs. 667 ± 137 W; p = 0.008) and mean power during the Wingate test (527 ± 111 vs. 518 ± 111 W; p < 0.001) with no differences between AA homozygotes and C-allele carriers (p > 0.05). Reaction times were similar between caffeine and placebo conditions (276 ± 31 vs. 269 ± 71 milliseconds; p = 0.681) with no differences between AA homozygotes and C-allele carriers. However, 31.3% of the C-allele carriers reported increased nervousness after caffeine ingestion, while none of the AA homozygotes perceived this side effect. Genetic variations of the CYP1A2 polymorphism did not affect the ergogenic effects and drawbacks derived from the ingestion of a moderate dose of caffeine.
International Journal of Performance Analysis in Sport, 2015
The aim of this investigation was to determine age-related factors of the top 100 ranked men and ... more The aim of this investigation was to determine age-related factors of the top 100 ranked men and women tennis players over the last few decades. The birth date and the ranking position of 1,040 top-100 tennis players (647 men and 393 women) were obtained from official public websites. The mean age of top 100 male tennis players increased significantly from 1984 to 2013 (24.6 ± 3.9 to 27.6 ± 3.2 yr; P < 0.01) and it was also observed in female tennis players from 1998 to 2013 (23.5 ± 3.5 to 24.8 ± 4.2 yr; P < 0.01). On average, a top 100 ranking was reached earlier in women than in men (21.6 ± 3.4 vs 22.8 ± 3.1 yr; P < 0.05). Peak performance was also attained significantly earlier in women than in men (23.6 ± 3.5 vs 24.8 ± 2.9 yr; P < 0.01). Nevertheless, men remained in the top 100 ranking for a slightly longer period than women (4.1 ± 3.1 and 4.6 ± 3.8 yr; P < 0.01). These data indicate a movement towards older ages in top 100 women and men tennis players. This information might be useful for developing process/plans towards longer-term careers.
PloS one, 2017
Exertional rhabdomyolysis can occur in individuals performing various types of exercise but it is... more Exertional rhabdomyolysis can occur in individuals performing various types of exercise but it is unclear why some individuals develop this condition while others do not. Previous investigations have determined the role of several single nucleotide polymorphisms (SNPs) to explain inter-individual variability of serum creatine kinase (CK) concentrations after exertional muscle damage. However, there has been no research about the interrelationship among these SNPs. The purpose of this investigation was to analyze seven SNPs that are candidates for explaining individual variations of CK response after a marathon competition (ACE = 287bp Ins/Del, ACTN3 = p.R577X, CKMM = NcoI, IGF2 = C13790G, IL6 = 174G>C, MLCK = C37885A, TNFα = 308G>A). Using Williams and Folland's model, we determined the total genotype score from the accumulated combination of these seven SNPs for marathoners with a low CK response (n = 36; serum CK <400 U·L-1) vs. marathoners with a high CK response (n ...
European Journal of Applied Physiology, 2017
X allele carriers self-reported higher levels of lower limb muscle pain (7 ± 2 vs 6 ± 2 cm; P = 0... more X allele carriers self-reported higher levels of lower limb muscle pain (7 ± 2 vs 6 ± 2 cm; P = 0.02) than RR homozygotes at the end of the race. Conclusions In comparison to RR homozygotes, X allele carriers for the R577X polymorphism of the ACTN3 gene presented higher values for typical markers of exerciseinduced muscle damage during a competitive marathon. Thus, the absence of a functional α-actinin-3 produced by the X allele might induce higher levels of muscle breakdown during prolonged running events. Keywords α-Actinins • Rhabdomyolysis • Muscle pain • Endurance exercise • Genetics • Single-nucleotide polymorphism. Abbreviations Δ Percentage of difference ACTN2 α-Actinin-2 gene ACTN3 α-Actinin-3 gene A.U.
Journal of Strength and Conditioning Research, 2017
The aim of this study was to assess different physiological variables before and after a 5-km (wo... more The aim of this study was to assess different physiological variables before and after a 5-km (women) and 10-km (men) crosscountry skiing competition to determine potential mechanisms of fatigue. Fourteen elite-level skiers competed in an official crosscountry skiing competition using the classical style (9 men and 5 women). Instantaneous skiing velocity was measured during the race by means of 15-Hz global positioning system devices. Before and after the race, a sample of venous blood was obtained to assess changes in blood lactate and serum electrolyte and myoglobin concentrations. Prerace to postrace changes in blood oxygen saturation, forced vital capacity during a spirometry test, jump height during a countermovement jump, and handgrip force were also measured. Mean race speed was 15.8 6 2.5 and 15.4 6 1.5 km$h 21 , whereas mean heart rate was 171 6 6 and 177 6 3 b$min 21 for men and women, respectively. There were no significant prerace to postrace changes in jump height, handgrip force, and forced vital capacity in men and women. Blood oxygen saturation was reduced from prerace to postrace in men (95.9 6 2.1% to 93.1 6 2.3%, p = 0.02) and women (97.8 6 1.1% to 92.4 6 2.1%, p , 0.01), whereas blood lactate concentration increased at the end of the race in men (1.4 6 0.5 to 4.9 6 2.1 mmol$L 21 , p , 0.01) and women (1.9 6 0.1 to 6.9 6 3.2 mmol$L 21 , p , 0.01). After the race, blood markers of muscle damage were at low concentrations, whereas serum electrolytes remained unchanged. Fatigue in 5and 10-km crosscountry skiing competitions was related to a reduced blood oxygen carrying capacity and presumably increased muscle and blood acidosis, whereas the influence of exercise-induced muscle damage on fatigue was minor.
The Journal of sports medicine and physical fitness, Jan 6, 2016
The aim of the study was to analyze the relationship between anthropometry, training characterist... more The aim of the study was to analyze the relationship between anthropometry, training characteristics, muscular strength and effort-related cardiovascular response and marathon race time in male amateur runners. A total of 84 male amateur marathon runners aged between 23 and 70 years took part in this study (41.0±9.5 years). All of them competed in the 2013 edition of the Madrid Marathon with a finish time between 169.8 and 316 min (226.0±28.5 min). Age, running experience, number of marathon races finished, mean kilometres run weekly in the last three months, and previous personal best time in the 10 km, half marathon and marathon were recorded. Moreover, anthropometric characteristics, and the results from the Ruffier test and a whole-body isometric force test were measured. After the marathon, the race time was registered. Training volume (r=-0.479; P=0.001), previous running milestones (marathon r=0.756; half-marathon r=0.812; 10-km r= 0.732; P<0.001), cardiovascular fitness (...
Journal of Strength and Conditioning Research, 2017
Puente, C, Abián-Vicén, J, Areces, F, López, R, and Del Coso, J. Physical and physiological deman... more Puente, C, Abián-Vicén, J, Areces, F, López, R, and Del Coso, J. Physical and physiological demands of experienced male basketball players during a competitive game. J Strength Cond Res 31(4): 956–962, 2017—The aim of this investigation was to analyze the physical and physiological demands of experienced basketball players during a real and competitive game. Twenty-five well-trained basketball players (8 guards, 8 forwards, and 9 centers) played a competitive game on an outdoor court. Instantaneous running speeds, the number of body impacts above 5 g, and the number of accelerations and decelerations were assessed by means of a 15-Hz global Positioning System accelerometer unit. Individual heart rate was also recorded using heart rate monitors. As a group mean, the basketball players covered 82.6 ± 7.8 m·min−1 during the game with a mean heart rate of 89.8 ± 4.4% of maximal heart rate. Players covered 3 ± 3% of the total distance running at above 18 km·h−1 and performed 0.17 ± 0.13 ...
PLOS ONE, 2016
Myosin light chain kinase (MLCK) phosphorylates the regulatory light chain (RLC) of myosin produc... more Myosin light chain kinase (MLCK) phosphorylates the regulatory light chain (RLC) of myosin producing increases in force development during skeletal muscle contraction. It has been suggested that MLCK gene polymorphisms might alter RLC phosphorylation thereby decreasing the ability to produce force and to resist strain during voluntary muscle contractions. Thus, the genetic variations in the MLCK gene might predispose some individuals to higher values of muscle damage during exercise, especially during endurance competitions. The aim of this investigation was to determine the influence of MLCK genetic variants on exercise-induced muscle damage produced during a marathon. Sixty-seven experienced runners competed in a marathon race. The MLCK genotype (C37885A) of these marathoners was determined. Before and after the race, a sample of venous blood was obtained to assess changes in serum myoglobin concentrations and leg muscle power changes were measured during a countermovement jump. Self-reported leg muscle pain and fatigue were determined by questionnaires. A total of 59 marathoners (88.1%) were CC homozygotes and 8 marathoners (11.9%) were CA heterozygotes. The two groups of participants completed the race with a similar time (228 ± 33 vs 234 ± 39 min; P = 0.30) and similar self-reported values for fatigue (15 ± 2 vs 16 ± 2 A.U.; P = 0.21) and lower-limb muscle pain (6.2 ± 1.7 vs 6.6 ± 1.8 cm; P = 0.29). However, CC marathoners presented higher serum myoglobin concentrations (739 ± 792 vs 348 ± 144 μgÁmL-1 ; P = 0.03) and greater pre-to-post-race leg muscle power reduction (-32.7 ± 15.7 vs-21.2 ± 21.6%; P = 0.05) than CA marathoners. CA heterozygotes for MLCK C37885A might present higher exerciseinduced muscle damage after a marathon competition than CC counterparts.
Journal of the International Society of Sports Nutrition, 2016
Background: Sodium (Na +) intake during exercise aims to replace the Na + lost by sweat to avoid ... more Background: Sodium (Na +) intake during exercise aims to replace the Na + lost by sweat to avoid electrolyte imbalances, especially in endurance disciplines. However, Na + needs can be very different among individuals because of the great inter-individual variability in sweat electrolyte concentration. The aim of this investigation was to determine sweat electrolyte concentration in a large group of marathoners. Methods: A total of 157 experienced runners (141 men and 16 women) completed a marathon race (24.4 ± 3.6°C and 27.7 ± 4.8 % of humidity). During the race, sweat samples were collected by using sweat patches placed on the runners' forearms. Sweat electrolyte concentration was measured by using photoelectric flame photometry. Results: As a group, sweat Na + concentration was 42.9 ± 18.7 mmol•L −1 (minimal-maximal value = 7.0-95.5 mmol•L −1), sweat Cl − concentration was 32.2 ± 15.6 mmol•L −1 (7.3-90.6 mmol•L −1) and sweat K + concentration was 6.0 ± 0. 9 mmol•L −1 (3.1-8.0 mmol•L −1). Women presented lower sweat Na + (33.9 ± 12.1 vs 44.0 ± 19.1 mmol•L −1 ; P = 0.04) and sweat Cl − concentrations (22.9 ± 10.5 vs 33.2 ± 15.8 mmol•L −1 ; P = 0.01) than men. A 20 % of individuals presented a sweat Na + concentration higher than 60 mmol•L −1 while this threshold was not surpassed by any female marathoner. Sweat electrolyte concentration did not correlate to sweat rate, age, body characteristics, experience or training. Although there was a significant correlation between sweat Na + concentration and running pace (r = 0.18; P = 0.03), this association was weak to interpret that sweat Na + concentration increased with running pace. Conclusions: The inter-individual variability in sweat electrolyte concentration was not explained by any individual characteristics except for individual running pace and sex. An important portion (20 %) of marathoners might need special sodium intake recommendations due to their high sweat salt losses.
European Journal of Sport Science, 2016
Scientific information about the effects of caffeine intake on combat sport performance is scarce... more Scientific information about the effects of caffeine intake on combat sport performance is scarce and controversial. The aim of this study was to investigate the effectiveness of caffeine to improve Brazilian Jiu-jitsu (BJJ)-specific muscular performance. Fourteen male and elite BJJ athletes (29.2 ± 3.3 years; 71.3 ± 9.1 kg) participated in a randomized double-blind, placebo-controlled and crossover experiment. In two different sessions, BJJ athletes ingested 3 mg kg(-1) of caffeine or a placebo. After 60 min, they performed a handgrip maximal force test, a countermovement jump, a maximal static lift test and bench-press tests consisting of one-repetition maximum, power-load, and repetitions to failure. In comparison to the placebo, the ingestion of the caffeine increased: hand grip force in both hands (50.9 ± 2.9 vs. 53.3 ± 3.1 kg; respectively p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .05), countermovement jump height (40.6 ± 2.6 vs. 41.7 ± 3.1 cm; p = .02), and time recorded in the maximal static lift test (54.4 ± 13.4 vs. 59.2 ± 11.9 s;…
Publice Premium, Jun 4, 2014
PLOS ONE, 2015
The aim of this study was to investigate the relationship between changes in serum free amino aci... more The aim of this study was to investigate the relationship between changes in serum free amino acids, muscle fatigue and exercise-induced muscle damage during a half-ironman triathlon. Twenty-six experienced triathletes (age = 37.0 ± 6.8 yr; experience = 7.4 ± 3.0 yr) competed in a real half-ironman triathlon in which sector times and total race time were measured by means of chip timing. Before and after the race, a countermovement jump and a maximal isometric force test were performed, and blood samples were withdrawn to measure serum free amino acids concentrations, and serum creatine kinase levels as a blood marker of muscle damage. Total race time was 320 ± 37 min and jump height (-16.3 ± 15.2%, P < 0.001) and isometric force (-14.9 ± 9.8%; P = 0.007) were significantly reduced after the race in all participants. After the race, the serum concentration of creatine kinase increased by 368 ± 187% (P < 0.001). In contrast, the serum concentrations of essential (-27.1 ± 13.0%; P < 0.001) and non-essential amino acids (-24.4 ± 13.1%; P < 0.001) were significantly reduced after the race. The tryptophan/BCAA ratio increased by 42.7 ± 12.7% after the race. Pre-to-post changes in serum free amino acids did not correlate with muscle performance variables or post-race creatine kinase concentration. In summary, during a half-ironman triathlon, serum amino acids concentrations were reduced by > 20%. However, neither the changes in serum free amino acids nor the tryptophan/BCAA ratio were related muscle fatigue or muscle damage during the race.
British Journal of Nutrition, 2015
This study investigated the effect of a caffeinated energy drink on various aspects of performanc... more This study investigated the effect of a caffeinated energy drink on various aspects of performance in sprint swimmers. In a randomised and counterbalanced order, fourteen male sprint swimmers performed two acute experimental trials after the ingestion of a caffeinated energy drink (3 mg/kg) or after the ingestion of the same energy drink without caffeine (0 mg/kg; placebo). After 60 min of ingestion of the beverages, the swimmers performed a countermovement jump, a maximal handgrip test, a 50 m simulated competition and a 45 s swim at maximal intensity in a swim ergometer. A blood sample was withdrawn 1 min after the completion of the ergometer test. In comparison with the placebo drink, the intake of the caffeinated energy drink increased the height in the countermovement jump (49·4 (sd 5·3) v. 50·9 (sd 5·2) cm, respectively; P<0·05) and maximal force during the handgrip test with the right hand (481 (sd 49) v. 498 (sd 43) N; P<0·05). Furthermore, the caffeinated energy drink...
International Journal of Sport Nutrition and Exercise Metabolism, 2016
The aim of this investigation was to determine the efficacy of a caffeine-containing energy drink... more The aim of this investigation was to determine the efficacy of a caffeine-containing energy drink to improve physical performance of elite field hockey players during a game. On 2 days separated by a week, 13 elite field hockey players (age and body mass = 23.2 ± 3.9 years and 76.1 ± 6.1 kg) ingested 3 mg of caffeine per kg of body mass in the form of an energy drink or the same drink without caffeine (placebo drink). After 60 min for caffeine absorption, participants played a simulated field hockey game (2 × 25 min). Individual running pace and instantaneous speed during the game were assessed using GPS devices. The total number of accelerations and decelerations was determined by accelerometry. Compared with the placebo drink, the caffeinated energy drink did not modify the total distance covered during the game (6,035 ± 451 m and 6,055 ± 499 m, respectively; p = .87), average heart rate (155 ± 13 beats per min and 158 ± 18 beats per min, respectively; p = .46), or the number of a...
Archivos de Medicina del Deporte
La maratón lleva asociado un estrés fi siológico en el organismo, si bien existe carencia de info... more La maratón lleva asociado un estrés fi siológico en el organismo, si bien existe carencia de información sobre cómo afecta a los parámetros sanguíneos en corredores populares y si existe relación con variables de rendimiento, entrenamiento y experiencia deportiva. Propósito: Evaluar los cambios producidos en variables hematológicas en corredores populares tras participar en una maratón en ambiente caluroso. Un segundo objetivo fue analizar la relación entre la experiencia deportiva, el nivel de entrenamiento y el tiempo de carrera con los cambios hematológicos. Métodos: Se extrajo sangre venosa a 41 maratonianos, 35 hombres y 6 mujeres, antes y después de una maratón. Su edad fue de 41,15+8,1 años, y entrenaban como media 55,917,12 kilómetros semanales. El tiempo en meta fue de 3:40:410:32:02. Las muestras fueron medidas con analizadores bioquímicos estándar para determinar los valores de la serie roja y serie blanca. Resultados: Se mostraron incrementos signifi cativos (P<0,05) en los valores de la serie roja, pasando los hematíes de 4,620,39 x10E3/uL a 4,710,42x10E3/uL, la hemoglobina de 14,331,02x10E6/uL a 14,581,13x10E6/uL, y el hematocrito de 42,122,98% a 42,83,19%. En la serie blanca se incrementó el recuento leucocitario (P<0,001), siendo el valor pre 6,291,33 x10E3/uL y el post 16,023,13x10E3/uL. La serie plaquetaria aumentó signifi cativamente tanto el recuento de plaquetas (pre 228,345,02x10E3/uL; post 272,945,83x10E3/uL, P<0,001) como el plaquetocrito (pre 2,030,3%; post 2,470,54%; P<0,001). El tiempo en meta presentó correlación signifi cativa, aunque débil, con el cambio entre la toma inicial y fi nal en el recuento de monocitos (r=-0,367; P=0,018), y en el volumen corpuscular medio (r=-0,485; P=0,001). Conclusión: La disputa de una carrera de maratón produce en corredores populares modifi caciones hematológicas agudas en los parámetros habituales medidos con analizadores bioquímicos estándar. La experiencia deportiva, nivel de entrenamiento y tiempo en meta no parecen tener especial relación con estos parámetros. Summary Introduction: Marathon supposes a physiological stress in the organism, but there is insuffi ciently information about how hematological values aff ecting runners. Also if there is relationship with performance, training and sporting experience variables. Purpose: The study was conducted to evaluate changes occurred in the main hematic variables in amateur runners, after their participation in a hot climate marathon. A second objective was to analyze the connection between sport experiences, training level and race time with the hematic changes. Methods: Blood samples were taken from 41 runners, 35 male and 6 female, before and immediately after the marathon. The mean training level was 55.9+17.12 km per week and the time race was 3:40:410:32:02 at a mean age of 41.158.1 years. Results: Samples were measured with biochemical standard analyzers and to determinate CBC and WBC counts. Signifi cant diff erences (P<0.05) were found in CBC counts, increasing values of red blood cell from 4.620,39 x10E3/uL to 4,71+0,42x10E3/ uL, haemoglobin from 14.331.02x10E6/uL to 14.581.13x10E6/uL and haematocrit from 42.122.98% to 42.83.19%. WBC counts showed also signifi cant changes in leukocyte values (P<0.001) from 6.29 1.33 to 16.02 3.13 x10E3/uL, as well as in both, platelets values (P<0.001) from 228.345.02x10E3/uL to 272.945.83x10E3/uL and plateletcrit values (P<0.001) from 2.030.3% to 2.470.54%. Race time was signifi cantly correlated between initial and fi nal monocite values, but poor (r=-0.367; P=0.018) and also between basal and fi nal mean corpuscular volume (r=-0.485; P=0.001). Conclusion: Acute hematological changes occur in amateur runners after a marathon. No relationship was found between the hematic parameters and sport experience, training level and race time.
Scandinavian Journal of Medicine & Science in Sports, 2015
The aim of this study was to investigate the effectiveness of oral salt supplementation to improv... more The aim of this study was to investigate the effectiveness of oral salt supplementation to improve exercise performance during a half‐ironman triathlon. Twenty‐six experienced triathletes were matched for age, anthropometric data, and training status, and randomly placed into the salt group (113 mmol Na+ and 112 mmol Cl−) or the control group (cellulose). The experimental treatments were ingested before and during a real half‐ironman triathlon competition. Pre‐ and post‐race body mass, maximal force during a whole‐body isometric strength test, maximal height during a countermovement jump, were measured, and blood samples were obtained. Sweat samples were obtained during the running section. Total race time was lower in the salt group than in the control group (P = 0.04). After the race, whole‐body isometric strength (P = 0.17) and jump height (P = 0.49) were similarly reduced in both groups. Sweat loss (P = 0.98) and sweat Na+ concentration (P = 0.72) were similar between groups. Ho...
British Journal of Nutrition, 2014
The use of caffeine containing energy drinks has dramatically increased in the last few years, es... more The use of caffeine containing energy drinks has dramatically increased in the last few years, especially in the sport context because of its reported ergogenic effect. The ingestion of low to moderate doses of caffeinated energy drinks has been associated with adverse side effects such as insomnia or increased nervousness. The aim of the present study was to assess psycho-physiological changes and the prevalence of side effects resulting from the ingestion of 3 mg caffeine/kg body mass in the form of an energy drink. In a double-blind and placebo controlled experimental design, ninety experienced and low-caffeine-consuming athletes (fifty-three male and thirty-seven female) in two different sessions were provided with an energy drink that contained 3 mg/kg of caffeine or the same decaffeinated energy drink (placebo; 0 mg/kg). At 60 min after the ingestion of the energy drink, participants completed a training session. The effects of ingestion of these beverages on psycho-physiologi...
Revista Brasileira de Medicina do Esporte, 2020
Introduction: This study aimed to measure thickness and cross-sectional area of the Achilles tend... more Introduction: This study aimed to measure thickness and cross-sectional area of the Achilles tendon (AT), and the range of motion of the ankle joint in dorsiflexion of amateur marathon runners compared to non-active people. Objectives: To analyze the relationship between cross-sectional area and thickness of the Achilles tendon in marathon runners and age, anthropometric characteristics (height and body mass), training habits, running experience, marathon performance, and range of motion in the ankle joint. Methods: Achilles tendon thickness and cross-sectional area were measured using ultrasound images of the left leg in 97 male amateur marathon runners (age 42.0 ± 9.6 years; height 175 ± 6 cm; and body mass 73.7 ± 8.6 kg), and 47 controls (39.9 ± 11.6 years; 176 ± 7 cm; 79.6 ± 16.1 kg). Results: Achilles tendon thickness (4.81 ± 0.77 vs. 4.60 ± 0.66 mm; p = 0.01) and cross-sectional area (60.41 ± 14.36 vs. 53.62 ± 9.90 mm2; p < 0.01) were greater in the marathon runners than in...
PLOS ONE, 2020
A common single nucleotide polymorphism in the ACTN3 gene might result in the complete deficiency... more A common single nucleotide polymorphism in the ACTN3 gene might result in the complete deficiency of α-actinin-3 (i.e., XX genotype). It has been found that ACTN3 XX individuals have several traits related to lessened muscle performance. This study aimed to determine the influence, if any, of ACTN3 genotypes on injury incidence of marathoners during the year preceding to participating in a competitive marathon race. Using a cross-sectional experimental design, the type and conditions of sports injuries were documented for one year in a group of 139 marathoners. Injuries were recorded following a consensus statement on injuries in Athletics. Afterward, ACTN3 genotyping was performed, and injury epidemiology was compared among RR, RX, and XX genotypes. The distribution of the RR/RX/XX genotypes was 28.8/42.8/23.5%, respectively. A total of 67 injuries were recorded. The frequency of marathoners that reported any injury during the previous year was not different across the genotypes (55.0/38.8/40.6%, P = 0.241). Although the overall injury incidence was not different among genotypes (2.78/1.65/1.94 injuries/1000 h of running, P = 0.084), the likelihood of suffering an injury was higher in RR than in RX (OR = 1.93: 95%CI = 0.87-4.30), and higher than in XX (OR = 1.79: 0.70-4.58). There was no difference in the conditions, severity, body location, time of year, or leading cause of injury among genotypes. However, XX presented a higher frequency of sudden-onset injuries (P = 0.024), and the OR for muscle-type injuries was 2.0 (0.51-7.79) times higher compared to RR runners. Although XX marathoners did not have a higher overall incidence of injury, the OR in these runners for muscle-type injuries was superior to RR and RX runners. The likelihood of suffering a muscle injury, especially with a sudden-onset, was twice in XX than in RR endurance runners.
Nutrients, 2017
The aim of this study was to determine the effect of caffeine intake on overall basketball perfor... more The aim of this study was to determine the effect of caffeine intake on overall basketball performance in experienced players. A double-blind, placebo-controlled, randomized experimental design was used for this investigation. In two different sessions separated by one week, 20 experienced basketball players ingested 3 mg of caffeine/kg of body mass or a placebo. After 60 min, participants performed 10 repetitions of the following sequence: Abalakov jump, Change-of-Direction and Acceleration Test (CODAT) and two free throws. Later, heart rate, body impacts and game statistics were recorded during a 20-min simulated basketball game. In comparison to the placebo, the ingestion of caffeine increased mean jump height (37.3 ± 6.8 vs. 38.2 ± 7.4 cm; p = 0.012), but did not change mean time in the CODAT test or accuracy in free throws. During the simulated game, caffeine increased the number of body impacts (396 ± 43 vs. 410 ± 41 impacts/min; p < 0.001) without modifying mean or peak heart rate. Caffeine also increased the performance index rating (7.2 ± 8.6 vs. 10.6 ± 7.1; p = 0.037) during the game. Nevertheless, players showed a higher prevalence of insomnia (19.0 vs. 54.4%; p = 0.041) after the game. Three mg of caffeine per kg of body mass could be an effective ergogenic substance to increase physical performance and overall success in experienced basketball players.
Nutrients, 2017
Previous investigations have determined that some individuals have minimal or even ergolytic perf... more Previous investigations have determined that some individuals have minimal or even ergolytic performance effects after caffeine ingestion. The aim of this study was to analyze the influence of the genetic variations of the CYP1A2 gene on the performance enhancement effects of ingesting a moderate dose of caffeine. In a double-blind randomized experimental design, 21 healthy active participants (29.3 ± 7.7 years) ingested 3 mg of caffeine per kg of body mass or a placebo in testing sessions separated by one week. Performance in the 30 s Wingate test, visual attention, and side effects were evaluated. DNA was obtained from whole blood samples and the CYP1A2 polymorphism was analyzed (rs762551). We obtained two groups: AA homozygotes (n = 5) and C-allele carriers (n = 16). Caffeine ingestion increased peak power (682 ± 140 vs. 667 ± 137 W; p = 0.008) and mean power during the Wingate test (527 ± 111 vs. 518 ± 111 W; p < 0.001) with no differences between AA homozygotes and C-allele carriers (p > 0.05). Reaction times were similar between caffeine and placebo conditions (276 ± 31 vs. 269 ± 71 milliseconds; p = 0.681) with no differences between AA homozygotes and C-allele carriers. However, 31.3% of the C-allele carriers reported increased nervousness after caffeine ingestion, while none of the AA homozygotes perceived this side effect. Genetic variations of the CYP1A2 polymorphism did not affect the ergogenic effects and drawbacks derived from the ingestion of a moderate dose of caffeine.
International Journal of Performance Analysis in Sport, 2015
The aim of this investigation was to determine age-related factors of the top 100 ranked men and ... more The aim of this investigation was to determine age-related factors of the top 100 ranked men and women tennis players over the last few decades. The birth date and the ranking position of 1,040 top-100 tennis players (647 men and 393 women) were obtained from official public websites. The mean age of top 100 male tennis players increased significantly from 1984 to 2013 (24.6 ± 3.9 to 27.6 ± 3.2 yr; P < 0.01) and it was also observed in female tennis players from 1998 to 2013 (23.5 ± 3.5 to 24.8 ± 4.2 yr; P < 0.01). On average, a top 100 ranking was reached earlier in women than in men (21.6 ± 3.4 vs 22.8 ± 3.1 yr; P < 0.05). Peak performance was also attained significantly earlier in women than in men (23.6 ± 3.5 vs 24.8 ± 2.9 yr; P < 0.01). Nevertheless, men remained in the top 100 ranking for a slightly longer period than women (4.1 ± 3.1 and 4.6 ± 3.8 yr; P < 0.01). These data indicate a movement towards older ages in top 100 women and men tennis players. This information might be useful for developing process/plans towards longer-term careers.
PloS one, 2017
Exertional rhabdomyolysis can occur in individuals performing various types of exercise but it is... more Exertional rhabdomyolysis can occur in individuals performing various types of exercise but it is unclear why some individuals develop this condition while others do not. Previous investigations have determined the role of several single nucleotide polymorphisms (SNPs) to explain inter-individual variability of serum creatine kinase (CK) concentrations after exertional muscle damage. However, there has been no research about the interrelationship among these SNPs. The purpose of this investigation was to analyze seven SNPs that are candidates for explaining individual variations of CK response after a marathon competition (ACE = 287bp Ins/Del, ACTN3 = p.R577X, CKMM = NcoI, IGF2 = C13790G, IL6 = 174G>C, MLCK = C37885A, TNFα = 308G>A). Using Williams and Folland's model, we determined the total genotype score from the accumulated combination of these seven SNPs for marathoners with a low CK response (n = 36; serum CK <400 U·L-1) vs. marathoners with a high CK response (n ...
European Journal of Applied Physiology, 2017
X allele carriers self-reported higher levels of lower limb muscle pain (7 ± 2 vs 6 ± 2 cm; P = 0... more X allele carriers self-reported higher levels of lower limb muscle pain (7 ± 2 vs 6 ± 2 cm; P = 0.02) than RR homozygotes at the end of the race. Conclusions In comparison to RR homozygotes, X allele carriers for the R577X polymorphism of the ACTN3 gene presented higher values for typical markers of exerciseinduced muscle damage during a competitive marathon. Thus, the absence of a functional α-actinin-3 produced by the X allele might induce higher levels of muscle breakdown during prolonged running events. Keywords α-Actinins • Rhabdomyolysis • Muscle pain • Endurance exercise • Genetics • Single-nucleotide polymorphism. Abbreviations Δ Percentage of difference ACTN2 α-Actinin-2 gene ACTN3 α-Actinin-3 gene A.U.
Journal of Strength and Conditioning Research, 2017
The aim of this study was to assess different physiological variables before and after a 5-km (wo... more The aim of this study was to assess different physiological variables before and after a 5-km (women) and 10-km (men) crosscountry skiing competition to determine potential mechanisms of fatigue. Fourteen elite-level skiers competed in an official crosscountry skiing competition using the classical style (9 men and 5 women). Instantaneous skiing velocity was measured during the race by means of 15-Hz global positioning system devices. Before and after the race, a sample of venous blood was obtained to assess changes in blood lactate and serum electrolyte and myoglobin concentrations. Prerace to postrace changes in blood oxygen saturation, forced vital capacity during a spirometry test, jump height during a countermovement jump, and handgrip force were also measured. Mean race speed was 15.8 6 2.5 and 15.4 6 1.5 km$h 21 , whereas mean heart rate was 171 6 6 and 177 6 3 b$min 21 for men and women, respectively. There were no significant prerace to postrace changes in jump height, handgrip force, and forced vital capacity in men and women. Blood oxygen saturation was reduced from prerace to postrace in men (95.9 6 2.1% to 93.1 6 2.3%, p = 0.02) and women (97.8 6 1.1% to 92.4 6 2.1%, p , 0.01), whereas blood lactate concentration increased at the end of the race in men (1.4 6 0.5 to 4.9 6 2.1 mmol$L 21 , p , 0.01) and women (1.9 6 0.1 to 6.9 6 3.2 mmol$L 21 , p , 0.01). After the race, blood markers of muscle damage were at low concentrations, whereas serum electrolytes remained unchanged. Fatigue in 5and 10-km crosscountry skiing competitions was related to a reduced blood oxygen carrying capacity and presumably increased muscle and blood acidosis, whereas the influence of exercise-induced muscle damage on fatigue was minor.
The Journal of sports medicine and physical fitness, Jan 6, 2016
The aim of the study was to analyze the relationship between anthropometry, training characterist... more The aim of the study was to analyze the relationship between anthropometry, training characteristics, muscular strength and effort-related cardiovascular response and marathon race time in male amateur runners. A total of 84 male amateur marathon runners aged between 23 and 70 years took part in this study (41.0±9.5 years). All of them competed in the 2013 edition of the Madrid Marathon with a finish time between 169.8 and 316 min (226.0±28.5 min). Age, running experience, number of marathon races finished, mean kilometres run weekly in the last three months, and previous personal best time in the 10 km, half marathon and marathon were recorded. Moreover, anthropometric characteristics, and the results from the Ruffier test and a whole-body isometric force test were measured. After the marathon, the race time was registered. Training volume (r=-0.479; P=0.001), previous running milestones (marathon r=0.756; half-marathon r=0.812; 10-km r= 0.732; P<0.001), cardiovascular fitness (...
Journal of Strength and Conditioning Research, 2017
Puente, C, Abián-Vicén, J, Areces, F, López, R, and Del Coso, J. Physical and physiological deman... more Puente, C, Abián-Vicén, J, Areces, F, López, R, and Del Coso, J. Physical and physiological demands of experienced male basketball players during a competitive game. J Strength Cond Res 31(4): 956–962, 2017—The aim of this investigation was to analyze the physical and physiological demands of experienced basketball players during a real and competitive game. Twenty-five well-trained basketball players (8 guards, 8 forwards, and 9 centers) played a competitive game on an outdoor court. Instantaneous running speeds, the number of body impacts above 5 g, and the number of accelerations and decelerations were assessed by means of a 15-Hz global Positioning System accelerometer unit. Individual heart rate was also recorded using heart rate monitors. As a group mean, the basketball players covered 82.6 ± 7.8 m·min−1 during the game with a mean heart rate of 89.8 ± 4.4% of maximal heart rate. Players covered 3 ± 3% of the total distance running at above 18 km·h−1 and performed 0.17 ± 0.13 ...
PLOS ONE, 2016
Myosin light chain kinase (MLCK) phosphorylates the regulatory light chain (RLC) of myosin produc... more Myosin light chain kinase (MLCK) phosphorylates the regulatory light chain (RLC) of myosin producing increases in force development during skeletal muscle contraction. It has been suggested that MLCK gene polymorphisms might alter RLC phosphorylation thereby decreasing the ability to produce force and to resist strain during voluntary muscle contractions. Thus, the genetic variations in the MLCK gene might predispose some individuals to higher values of muscle damage during exercise, especially during endurance competitions. The aim of this investigation was to determine the influence of MLCK genetic variants on exercise-induced muscle damage produced during a marathon. Sixty-seven experienced runners competed in a marathon race. The MLCK genotype (C37885A) of these marathoners was determined. Before and after the race, a sample of venous blood was obtained to assess changes in serum myoglobin concentrations and leg muscle power changes were measured during a countermovement jump. Self-reported leg muscle pain and fatigue were determined by questionnaires. A total of 59 marathoners (88.1%) were CC homozygotes and 8 marathoners (11.9%) were CA heterozygotes. The two groups of participants completed the race with a similar time (228 ± 33 vs 234 ± 39 min; P = 0.30) and similar self-reported values for fatigue (15 ± 2 vs 16 ± 2 A.U.; P = 0.21) and lower-limb muscle pain (6.2 ± 1.7 vs 6.6 ± 1.8 cm; P = 0.29). However, CC marathoners presented higher serum myoglobin concentrations (739 ± 792 vs 348 ± 144 μgÁmL-1 ; P = 0.03) and greater pre-to-post-race leg muscle power reduction (-32.7 ± 15.7 vs-21.2 ± 21.6%; P = 0.05) than CA marathoners. CA heterozygotes for MLCK C37885A might present higher exerciseinduced muscle damage after a marathon competition than CC counterparts.
Journal of the International Society of Sports Nutrition, 2016
Background: Sodium (Na +) intake during exercise aims to replace the Na + lost by sweat to avoid ... more Background: Sodium (Na +) intake during exercise aims to replace the Na + lost by sweat to avoid electrolyte imbalances, especially in endurance disciplines. However, Na + needs can be very different among individuals because of the great inter-individual variability in sweat electrolyte concentration. The aim of this investigation was to determine sweat electrolyte concentration in a large group of marathoners. Methods: A total of 157 experienced runners (141 men and 16 women) completed a marathon race (24.4 ± 3.6°C and 27.7 ± 4.8 % of humidity). During the race, sweat samples were collected by using sweat patches placed on the runners' forearms. Sweat electrolyte concentration was measured by using photoelectric flame photometry. Results: As a group, sweat Na + concentration was 42.9 ± 18.7 mmol•L −1 (minimal-maximal value = 7.0-95.5 mmol•L −1), sweat Cl − concentration was 32.2 ± 15.6 mmol•L −1 (7.3-90.6 mmol•L −1) and sweat K + concentration was 6.0 ± 0. 9 mmol•L −1 (3.1-8.0 mmol•L −1). Women presented lower sweat Na + (33.9 ± 12.1 vs 44.0 ± 19.1 mmol•L −1 ; P = 0.04) and sweat Cl − concentrations (22.9 ± 10.5 vs 33.2 ± 15.8 mmol•L −1 ; P = 0.01) than men. A 20 % of individuals presented a sweat Na + concentration higher than 60 mmol•L −1 while this threshold was not surpassed by any female marathoner. Sweat electrolyte concentration did not correlate to sweat rate, age, body characteristics, experience or training. Although there was a significant correlation between sweat Na + concentration and running pace (r = 0.18; P = 0.03), this association was weak to interpret that sweat Na + concentration increased with running pace. Conclusions: The inter-individual variability in sweat electrolyte concentration was not explained by any individual characteristics except for individual running pace and sex. An important portion (20 %) of marathoners might need special sodium intake recommendations due to their high sweat salt losses.
European Journal of Sport Science, 2016
Scientific information about the effects of caffeine intake on combat sport performance is scarce... more Scientific information about the effects of caffeine intake on combat sport performance is scarce and controversial. The aim of this study was to investigate the effectiveness of caffeine to improve Brazilian Jiu-jitsu (BJJ)-specific muscular performance. Fourteen male and elite BJJ athletes (29.2 ± 3.3 years; 71.3 ± 9.1 kg) participated in a randomized double-blind, placebo-controlled and crossover experiment. In two different sessions, BJJ athletes ingested 3 mg kg(-1) of caffeine or a placebo. After 60 min, they performed a handgrip maximal force test, a countermovement jump, a maximal static lift test and bench-press tests consisting of one-repetition maximum, power-load, and repetitions to failure. In comparison to the placebo, the ingestion of the caffeine increased: hand grip force in both hands (50.9 ± 2.9 vs. 53.3 ± 3.1 kg; respectively p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .05), countermovement jump height (40.6 ± 2.6 vs. 41.7 ± 3.1 cm; p = .02), and time recorded in the maximal static lift test (54.4 ± 13.4 vs. 59.2 ± 11.9 s;…
Publice Premium, Jun 4, 2014
PLOS ONE, 2015
The aim of this study was to investigate the relationship between changes in serum free amino aci... more The aim of this study was to investigate the relationship between changes in serum free amino acids, muscle fatigue and exercise-induced muscle damage during a half-ironman triathlon. Twenty-six experienced triathletes (age = 37.0 ± 6.8 yr; experience = 7.4 ± 3.0 yr) competed in a real half-ironman triathlon in which sector times and total race time were measured by means of chip timing. Before and after the race, a countermovement jump and a maximal isometric force test were performed, and blood samples were withdrawn to measure serum free amino acids concentrations, and serum creatine kinase levels as a blood marker of muscle damage. Total race time was 320 ± 37 min and jump height (-16.3 ± 15.2%, P < 0.001) and isometric force (-14.9 ± 9.8%; P = 0.007) were significantly reduced after the race in all participants. After the race, the serum concentration of creatine kinase increased by 368 ± 187% (P < 0.001). In contrast, the serum concentrations of essential (-27.1 ± 13.0%; P < 0.001) and non-essential amino acids (-24.4 ± 13.1%; P < 0.001) were significantly reduced after the race. The tryptophan/BCAA ratio increased by 42.7 ± 12.7% after the race. Pre-to-post changes in serum free amino acids did not correlate with muscle performance variables or post-race creatine kinase concentration. In summary, during a half-ironman triathlon, serum amino acids concentrations were reduced by > 20%. However, neither the changes in serum free amino acids nor the tryptophan/BCAA ratio were related muscle fatigue or muscle damage during the race.
British Journal of Nutrition, 2015
This study investigated the effect of a caffeinated energy drink on various aspects of performanc... more This study investigated the effect of a caffeinated energy drink on various aspects of performance in sprint swimmers. In a randomised and counterbalanced order, fourteen male sprint swimmers performed two acute experimental trials after the ingestion of a caffeinated energy drink (3 mg/kg) or after the ingestion of the same energy drink without caffeine (0 mg/kg; placebo). After 60 min of ingestion of the beverages, the swimmers performed a countermovement jump, a maximal handgrip test, a 50 m simulated competition and a 45 s swim at maximal intensity in a swim ergometer. A blood sample was withdrawn 1 min after the completion of the ergometer test. In comparison with the placebo drink, the intake of the caffeinated energy drink increased the height in the countermovement jump (49·4 (sd 5·3) v. 50·9 (sd 5·2) cm, respectively; P<0·05) and maximal force during the handgrip test with the right hand (481 (sd 49) v. 498 (sd 43) N; P<0·05). Furthermore, the caffeinated energy drink...
International Journal of Sport Nutrition and Exercise Metabolism, 2016
The aim of this investigation was to determine the efficacy of a caffeine-containing energy drink... more The aim of this investigation was to determine the efficacy of a caffeine-containing energy drink to improve physical performance of elite field hockey players during a game. On 2 days separated by a week, 13 elite field hockey players (age and body mass = 23.2 ± 3.9 years and 76.1 ± 6.1 kg) ingested 3 mg of caffeine per kg of body mass in the form of an energy drink or the same drink without caffeine (placebo drink). After 60 min for caffeine absorption, participants played a simulated field hockey game (2 × 25 min). Individual running pace and instantaneous speed during the game were assessed using GPS devices. The total number of accelerations and decelerations was determined by accelerometry. Compared with the placebo drink, the caffeinated energy drink did not modify the total distance covered during the game (6,035 ± 451 m and 6,055 ± 499 m, respectively; p = .87), average heart rate (155 ± 13 beats per min and 158 ± 18 beats per min, respectively; p = .46), or the number of a...
Archivos de Medicina del Deporte
La maratón lleva asociado un estrés fi siológico en el organismo, si bien existe carencia de info... more La maratón lleva asociado un estrés fi siológico en el organismo, si bien existe carencia de información sobre cómo afecta a los parámetros sanguíneos en corredores populares y si existe relación con variables de rendimiento, entrenamiento y experiencia deportiva. Propósito: Evaluar los cambios producidos en variables hematológicas en corredores populares tras participar en una maratón en ambiente caluroso. Un segundo objetivo fue analizar la relación entre la experiencia deportiva, el nivel de entrenamiento y el tiempo de carrera con los cambios hematológicos. Métodos: Se extrajo sangre venosa a 41 maratonianos, 35 hombres y 6 mujeres, antes y después de una maratón. Su edad fue de 41,15+8,1 años, y entrenaban como media 55,917,12 kilómetros semanales. El tiempo en meta fue de 3:40:410:32:02. Las muestras fueron medidas con analizadores bioquímicos estándar para determinar los valores de la serie roja y serie blanca. Resultados: Se mostraron incrementos signifi cativos (P<0,05) en los valores de la serie roja, pasando los hematíes de 4,620,39 x10E3/uL a 4,710,42x10E3/uL, la hemoglobina de 14,331,02x10E6/uL a 14,581,13x10E6/uL, y el hematocrito de 42,122,98% a 42,83,19%. En la serie blanca se incrementó el recuento leucocitario (P<0,001), siendo el valor pre 6,291,33 x10E3/uL y el post 16,023,13x10E3/uL. La serie plaquetaria aumentó signifi cativamente tanto el recuento de plaquetas (pre 228,345,02x10E3/uL; post 272,945,83x10E3/uL, P<0,001) como el plaquetocrito (pre 2,030,3%; post 2,470,54%; P<0,001). El tiempo en meta presentó correlación signifi cativa, aunque débil, con el cambio entre la toma inicial y fi nal en el recuento de monocitos (r=-0,367; P=0,018), y en el volumen corpuscular medio (r=-0,485; P=0,001). Conclusión: La disputa de una carrera de maratón produce en corredores populares modifi caciones hematológicas agudas en los parámetros habituales medidos con analizadores bioquímicos estándar. La experiencia deportiva, nivel de entrenamiento y tiempo en meta no parecen tener especial relación con estos parámetros. Summary Introduction: Marathon supposes a physiological stress in the organism, but there is insuffi ciently information about how hematological values aff ecting runners. Also if there is relationship with performance, training and sporting experience variables. Purpose: The study was conducted to evaluate changes occurred in the main hematic variables in amateur runners, after their participation in a hot climate marathon. A second objective was to analyze the connection between sport experiences, training level and race time with the hematic changes. Methods: Blood samples were taken from 41 runners, 35 male and 6 female, before and immediately after the marathon. The mean training level was 55.9+17.12 km per week and the time race was 3:40:410:32:02 at a mean age of 41.158.1 years. Results: Samples were measured with biochemical standard analyzers and to determinate CBC and WBC counts. Signifi cant diff erences (P<0.05) were found in CBC counts, increasing values of red blood cell from 4.620,39 x10E3/uL to 4,71+0,42x10E3/ uL, haemoglobin from 14.331.02x10E6/uL to 14.581.13x10E6/uL and haematocrit from 42.122.98% to 42.83.19%. WBC counts showed also signifi cant changes in leukocyte values (P<0.001) from 6.29 1.33 to 16.02 3.13 x10E3/uL, as well as in both, platelets values (P<0.001) from 228.345.02x10E3/uL to 272.945.83x10E3/uL and plateletcrit values (P<0.001) from 2.030.3% to 2.470.54%. Race time was signifi cantly correlated between initial and fi nal monocite values, but poor (r=-0.367; P=0.018) and also between basal and fi nal mean corpuscular volume (r=-0.485; P=0.001). Conclusion: Acute hematological changes occur in amateur runners after a marathon. No relationship was found between the hematic parameters and sport experience, training level and race time.
Scandinavian Journal of Medicine & Science in Sports, 2015
The aim of this study was to investigate the effectiveness of oral salt supplementation to improv... more The aim of this study was to investigate the effectiveness of oral salt supplementation to improve exercise performance during a half‐ironman triathlon. Twenty‐six experienced triathletes were matched for age, anthropometric data, and training status, and randomly placed into the salt group (113 mmol Na+ and 112 mmol Cl−) or the control group (cellulose). The experimental treatments were ingested before and during a real half‐ironman triathlon competition. Pre‐ and post‐race body mass, maximal force during a whole‐body isometric strength test, maximal height during a countermovement jump, were measured, and blood samples were obtained. Sweat samples were obtained during the running section. Total race time was lower in the salt group than in the control group (P = 0.04). After the race, whole‐body isometric strength (P = 0.17) and jump height (P = 0.49) were similarly reduced in both groups. Sweat loss (P = 0.98) and sweat Na+ concentration (P = 0.72) were similar between groups. Ho...
British Journal of Nutrition, 2014
The use of caffeine containing energy drinks has dramatically increased in the last few years, es... more The use of caffeine containing energy drinks has dramatically increased in the last few years, especially in the sport context because of its reported ergogenic effect. The ingestion of low to moderate doses of caffeinated energy drinks has been associated with adverse side effects such as insomnia or increased nervousness. The aim of the present study was to assess psycho-physiological changes and the prevalence of side effects resulting from the ingestion of 3 mg caffeine/kg body mass in the form of an energy drink. In a double-blind and placebo controlled experimental design, ninety experienced and low-caffeine-consuming athletes (fifty-three male and thirty-seven female) in two different sessions were provided with an energy drink that contained 3 mg/kg of caffeine or the same decaffeinated energy drink (placebo; 0 mg/kg). At 60 min after the ingestion of the energy drink, participants completed a training session. The effects of ingestion of these beverages on psycho-physiologi...