A. Cicchella - Academia.edu (original) (raw)
Papers by A. Cicchella
research and training applied to movement and sport sciences, 2015
The relationships of leptin with different anthropometric parameters, in normal, overweight and o... more The relationships of leptin with different anthropometric parameters, in normal, overweight and obese peripubertal boys, is not completely understood. Aim of the present investigation is to assess possible relationships of leptin with skinfolds thicknesses, and body segments in different BMI groups of prepubertal boys (Tanner). Methods. A sample of 248 boys (age 10-12 y) were divided (Cole et al. 2000) into three BMI subgroups: normal weight, n=190 (BMI<19.8-21.9); overweight, n=34 (BMI<24.0-26.8) and obese, n=24 (BMI 6524.0-26.8). 9 skinfolds and 13 circumferences were measured and the waist-to-hip ratio was calculated (tab.1). A 10 ml blood sample was obtained from the antecubital vein with the participant sitting in an upright position in the morning (8-9 a.m.) after an overnight fast. Leptin concentrations were determined by mean of an immunoassay ELISA sandwich method
Like other athletes, ballroom dancers often compete in short time in different countries under co... more Like other athletes, ballroom dancers often compete in short time in different countries under condition of high stress, subjecting them to risk of injury and burnout. In the present study, we measured the aerobic and anaerobic capacities (both during dance and during a simulated ballroom competition), agility, hand and abdominal strength, jumping capacity, flexibility, and balance in 16 top-level couples of ballroom dancers (8 males, 8 females). The in-season level of perceived stress and recovery was assessed using the Rest Q 76 questionnaire, and the relationship with aerobic and anaerobic capacity and with the other tests was studied. Our results show a very high level of aerobic/anaerobic fitness in this population, as well as a high level of stress in males. Balance and experience (age of the subjects) appear to be key characteristics linked to the position in the IDSF World Ranking (world ranking points = 8.67 age + 5.86 balance + 1174, 65; R 2 = 0.740). Emotional stress (r = 0.83, p = 0.04), social stress (r = 0.72, p = 0.032), and sleep quality (r = 0.92, p = 0.001) scales of the Rest Q appear also to be linked with balance but only in females. Med Probl Perform Art 2013; 28(2):65–69.
Acta Kinesiologiae Universitatis Tartuensis, 2012
Distance runners suffer often from overuse injures, caused by excessive pronation or supinating f... more Distance runners suffer often from overuse injures, caused by excessive pronation or supinating foot. The purpose of this study was to compare the rearfoot kinematics and the questionnaire results of incidences of overuse injuries symptoms. Fourteen distance runners, who were distributed into the more-symptomatic (MSL, n = 7) and less-symptomatic (LSL, n = 7) groups according to the questionnaire participated in this study. The subjects ran at average speed 3.79 m·s -1 on the 5,8 m runway with four markers set on rearfoot and shank, and kinematics were determined using the motion analysis system with 6 and 8 cameras. For the rearfoot kinematics analysis the angles between calcaneus and shank in both legs were measured: angle at impact; maximum angle; the pronation amplitude; time from impact to maximum angle; time from maximum angle to toe-off supination. The pronation amplitude in the right foot was greater (p < 0.05) in MSL compared to LSL group (5.5º and 8.2º, respectively; p = 0.02). The other measured parameters did not differ significantly between the groups. We concluded that the variations in rearfoot kinematics can not be the reasons for causing the symptoms of overuse and their origin should be searched from training errors.
Archives italiennes de biologie
This study investigated whether the altered organization of post-training sleep in patients with ... more This study investigated whether the altered organization of post-training sleep in patients with narcolepsy-cataplexy (NC) is associated with a lower off-line improvement in the consolidation of motor skills compared with normal subjects. Fourteen drug-naive NC patients, fulfilling the international clinical and polysomnographic diagnostic criteria, and 14 individually-matched controls underwent training at a sequential finger tapping task (FTT) and were re-tested on the next morning (after a night with polysomnographic recording) and after another six nights (spent at home). Training and retrieval sessions were performed in a controlled laboratory setting. FTT performance was worse in NC patients than controls at training and at both retrieval sessions and showed a fairly different time course (slower than in controls) of consolidation. Several sleep indices (lower values of stage-2 NREM sleep and SWS) were compatible with a lower effectiveness of sleep for consolidation of motor s...
Osteoporosis International, 2015
ABSTRACT
The Journal of sports medicine and physical fitness, 2010
The aim of the present study was to investigate changes in ghrelin and bone mineral density (BMD)... more The aim of the present study was to investigate changes in ghrelin and bone mineral density (BMD) during further biological maturation after onset of puberty in female adolescent swimmers. Swimmers (n=17) were tested once a year during a two year study period. At the first year, swimmers were at pubertal stages 2 & 3. Fasting plasma ghrelin, leptin, estradiol, insulin-like growth factor-1 (IGF-I) and BMD of the total body, lumbar spine and femoral neck were measured. Ghrelin did not change during the further pubertal development after onset of puberty. No differences in leptin were also seen during the study period. Estradiol and IGF-I were increased during further pubertal development. Total and lumbar spine BMD increased along with further biological maturation. In contrast, further pubertal development had no effect on femoral neck BMD in adolescent female swimmers. Ghrelin was not related to measured BMD values after adjusting for pubertal status at any measurement time. Ghrelin...
International Journal of Sports Medicine, 2009
The aim of our study was to examine the influence of elevated energy expenditure on ghrelin and B... more The aim of our study was to examine the influence of elevated energy expenditure on ghrelin and BMD in young male competitive swimmers advancing from prepubertal to pubertal maturation levels. The study included 19 healthy swimmers (pubertal stage 1) aged between 10 and 12 years. The participants were at the pubertal stages 2 and 3, and 3 and 4 at the second and third year, respectively. Ghrelin was decreased only after the first year. No changes were observed in leptin during the study period. Testosterone increased according to the pubertal development at each measurements. IGF-I was increased at the third measurement compared to the first two measurements. Total and lumbar spine BMDs increased according to the pubertal development in all boys at each measurements, while no changes in femoral neck BMD were observed. Ghrelin was not related to BMD after adjusting for pubertal status. We conclude that ghrelin was decreased at onset of puberty, while no further changes in ghrelin were seen with advancing pubertal stage. Total and lumbar spine BMD increased, while no changes in femoral neck BMD occurred. Ghrelin did not appear to have a direct influence on BMD in young male competitive swimmers.
Journal of Human Sport and Exercise, 2009
... Reference Data: Cicchella A, Jidong L, Jürimäe T, Zini M, Passariello C, Rizzo L, Stefanelli ... more ... Reference Data: Cicchella A, Jidong L, Jürimäe T, Zini M, Passariello C, Rizzo L, Stefanelli C. Anthropometric comparison between young estonian and chinese swimmers. J. Hum.Sport Exerc. 2009; 4(2):154-160. Corresponding author. ...
Medicine & Science in Sports & Exercise, 2010
Medicine & Science in Sports & Exercise, 2007
We examined the effect of regular physical activity on plasma ghrelin concentration after onset o... more We examined the effect of regular physical activity on plasma ghrelin concentration after onset of puberty in girls. In addition, we also examined the association of fasting plasma ghrelin concentration with various plasma biochemical, body composition, and aerobic capacity variables in healthy adolescent girls. Fifty healthy schoolgirls ages 11 to 16 yr were divided either into a physically active (N = 25) or a physically inactive (N = 25) group. The physically active group consisted of swimmers who had trained on an average of 6.2 +/- 2.0 h.wk(-1) for the last 2 yr, whereas the inclusion criterion for the physically inactive group was the participation in physical education classes only. The subjects were matched for age (+/- 1 yr) and body mass index (BMI; +/- 2 kg.m(-2)). Maturation I group (14 matched pairs) included pubertal stages 2 and 3, and maturation II group (11 matched pairs) included pubertal stages 4 and 5. Physically active girls had significantly higher (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) mean plasma ghrelin levels than the physically inactive girls (maturation I: 1152.1 +/- 312.9 vs 877.7 +/- 114.8 pg.mL(-1); maturation II: 1084.0 +/- 252.5 vs 793.4 +/- 164.9 pg.mL(-1)). Plasma ghrelin concentration was negatively related to percent body fat, fat mass, peak oxygen consumption per kilogram of body mass, leptin, estradiol, insulin, and insulin-like growth factor-I (IGF-I) (r &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; -0.298; P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). Multivariate linear regression analysis to determine the predictors of ghrelin concentration using the variables that were significantly associated with ghrelin concentration demonstrated that plasma IGF-I was the most important predictor of plasma ghrelin concentration (beta = -0.396; P = 0.008). Regular physical activity influences plasma ghrelin concentrations in girls with different pubertal maturation levels. Plasma IGF-I concentration seems to be the main determinant of circulating ghrelin in healthy, normal-weight adolescent girls.
Journal of Strength and Conditioning Research, 2006
The aim of this study was to investigate the concepts of electromyographic (EMG) threshold (EMGT)... more The aim of this study was to investigate the concepts of electromyographic (EMG) threshold (EMGT) by integrated EMG (iEMG) signals and neuromuscular fatigue threshold (NMFT) concepts in trained male athletes. Nine competitive national-level male rowers (21.8 +/- 4.4 years; 186.2 +/- 4.6 cm; 79.6 +/- 8.4 kg) took part in this investigation. Subjects were asked to participate in the graded exercise test to volitional exhaustion and 500-, 1,000-, and 2,000-m all-out rowing ergometer tests on a rowing ergometer. During all tests, oxygen consumption parameters, average power, and iEMG of the musculus vastus lateralis were recorded. The second ventilatory threshold (248.9 +/- 26.67 W) and EMGT (258.89 +/- 27.13 W) were not significantly different but were significantly lower than the NMFT (302.25 +/- 45.10 W). During 1,000- and 2,000-m all-out distances, VO(2) increased during the first minute and then leveled on a plateau with a slight decrease at the end of the exercise. Vastus lateralis activity showed a slight increase during all distances that was accompanied by a remarkable increase towards the end of the distance. All measured threshold values were significantly correlated (r &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 0.70; p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) to the rowing ergometer performance characteristics. It was concluded that EMGT is closely related to the aerobic-anaerobic transition phase, because NMFT represents the local fatigue accumulation in the muscle. NMFT indicates the performance capacity of the muscles; therefore, it helps coaches to better predict top athletes&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; performance.
Journal of Endocrinological Investigation, 2009
The aim of the present study was to assess the influence of regular physical activity on plasma g... more The aim of the present study was to assess the influence of regular physical activity on plasma ghrelin concentration in pre-pubertal and pubertal boys. In addition, the impact of ghrelin concentration on bone mineral density (BMD) was examined. In total, 56 healthy schoolboys aged between 10 and 16 yr were divided into the swimming (no.=28) and the control (no.=28) groups. The subjects were matched by age and body mass index (BMI), generating 9 matched pairs in pubertal group I (Tanner stage 1), 11 pairs in group II (Tanner stages 2 and 3), and 8 pairs in group III (Tanner stages 4 and 5). Swimmers in pubertal groups II and III had significantly (both p<0.05) higher mean ghrelin levels than the controls (group II: 1126.8+/-406.0 vs 868.3+/-411.2 pg/ml; group III: 1105.5+/-337.5 vs 850.8+/-306.0 pg/ml, respectively), whereas no difference was seen in the pubertal group I (1230.8+/-386.0 vs 1272.7+/-424.4 pg/ml). Ghrelin was the most important hormonal determinant for total BMD and lumbar apparent volumetric BMD (BMAD) (R2=27.2% and R2=19.8%, respectively) in swimmers, whereas in control boys, plasma IGF-I was the most important hormonal predictor accounting for 41.8% of the variability of total BMD and 20.4% of the variability of lumbar BMAD. In conclusion, ghrelin concentration decreased during puberty in physically inactive boys, while in regularly physically active boys it remained relatively unchanged. Ghrelin appears to be an important hormonal predictor for BMD in physically active boys, while BMD is mostly determined by IGF-I in physically inactive boys.
Journal of Biomechanics, 1994
Acta Paediatrica, 2010
Aim: To evaluate the relationships of visfatin, adiponectin and leptin with bone mineral density ... more Aim: To evaluate the relationships of visfatin, adiponectin and leptin with bone mineral density (BMD) and bone mineral content (BMC) in adolescent female athletes with different training patterns.
Eur J Appl Physiol, 2007
The purpose of the present study was to investigate the use of electromyographic signals (EMG), t... more The purpose of the present study was to investigate the use of electromyographic signals (EMG), to determine the EMG threshold (EMGT) in four lower extremity muscles and to compare these thresholds with the second ventilatory threshold (VT2) in subjects participating in different sports and at different performance levels. Forty-nine subjects (23.8 +/- 5.7 years, 182.7 +/- 5.3 cm, 79.1 +/- 8.6 kg) including eleven cyclists, ten team-handball players, nine kayakers, eight power lifters and eleven controls were investigated utilizing a cycle ergometer. Respiratory gas exchange measures were collected and EMG activity was continuously recorded from four muscles (vastus lateralis, vastus medialis, biceps femoris and gastrocnemius lateralis). The VO(2)max averaged 56.1 +/- 11.1 ml kg(-1) min(-1), the average aerobic power was 348.5 +/- 61.0 W and the corresponding VT2 occurred at 271.4 +/- 64.0 W. The EMGT ranged from 80 to 98% of power output for the different muscles. The VT2 and EMG thresholds from four different muscles were not different. When thresholds were analyzed among different groups of subjects, no significant difference was observed between VT2 and EMGT despite threshold differences between the groups. All four EMGT were significantly related to maximal aerobic power (r = 0.73-0.83) and were highly correlated to each other (r = 0.57-0.88). In conclusion, EMGT can be used to determine the VT2 for individuals independent of sport specificity or performance level.
research and training applied to movement and sport sciences, 2015
The relationships of leptin with different anthropometric parameters, in normal, overweight and o... more The relationships of leptin with different anthropometric parameters, in normal, overweight and obese peripubertal boys, is not completely understood. Aim of the present investigation is to assess possible relationships of leptin with skinfolds thicknesses, and body segments in different BMI groups of prepubertal boys (Tanner). Methods. A sample of 248 boys (age 10-12 y) were divided (Cole et al. 2000) into three BMI subgroups: normal weight, n=190 (BMI<19.8-21.9); overweight, n=34 (BMI<24.0-26.8) and obese, n=24 (BMI 6524.0-26.8). 9 skinfolds and 13 circumferences were measured and the waist-to-hip ratio was calculated (tab.1). A 10 ml blood sample was obtained from the antecubital vein with the participant sitting in an upright position in the morning (8-9 a.m.) after an overnight fast. Leptin concentrations were determined by mean of an immunoassay ELISA sandwich method
Like other athletes, ballroom dancers often compete in short time in different countries under co... more Like other athletes, ballroom dancers often compete in short time in different countries under condition of high stress, subjecting them to risk of injury and burnout. In the present study, we measured the aerobic and anaerobic capacities (both during dance and during a simulated ballroom competition), agility, hand and abdominal strength, jumping capacity, flexibility, and balance in 16 top-level couples of ballroom dancers (8 males, 8 females). The in-season level of perceived stress and recovery was assessed using the Rest Q 76 questionnaire, and the relationship with aerobic and anaerobic capacity and with the other tests was studied. Our results show a very high level of aerobic/anaerobic fitness in this population, as well as a high level of stress in males. Balance and experience (age of the subjects) appear to be key characteristics linked to the position in the IDSF World Ranking (world ranking points = 8.67 age + 5.86 balance + 1174, 65; R 2 = 0.740). Emotional stress (r = 0.83, p = 0.04), social stress (r = 0.72, p = 0.032), and sleep quality (r = 0.92, p = 0.001) scales of the Rest Q appear also to be linked with balance but only in females. Med Probl Perform Art 2013; 28(2):65–69.
Acta Kinesiologiae Universitatis Tartuensis, 2012
Distance runners suffer often from overuse injures, caused by excessive pronation or supinating f... more Distance runners suffer often from overuse injures, caused by excessive pronation or supinating foot. The purpose of this study was to compare the rearfoot kinematics and the questionnaire results of incidences of overuse injuries symptoms. Fourteen distance runners, who were distributed into the more-symptomatic (MSL, n = 7) and less-symptomatic (LSL, n = 7) groups according to the questionnaire participated in this study. The subjects ran at average speed 3.79 m·s -1 on the 5,8 m runway with four markers set on rearfoot and shank, and kinematics were determined using the motion analysis system with 6 and 8 cameras. For the rearfoot kinematics analysis the angles between calcaneus and shank in both legs were measured: angle at impact; maximum angle; the pronation amplitude; time from impact to maximum angle; time from maximum angle to toe-off supination. The pronation amplitude in the right foot was greater (p < 0.05) in MSL compared to LSL group (5.5º and 8.2º, respectively; p = 0.02). The other measured parameters did not differ significantly between the groups. We concluded that the variations in rearfoot kinematics can not be the reasons for causing the symptoms of overuse and their origin should be searched from training errors.
Archives italiennes de biologie
This study investigated whether the altered organization of post-training sleep in patients with ... more This study investigated whether the altered organization of post-training sleep in patients with narcolepsy-cataplexy (NC) is associated with a lower off-line improvement in the consolidation of motor skills compared with normal subjects. Fourteen drug-naive NC patients, fulfilling the international clinical and polysomnographic diagnostic criteria, and 14 individually-matched controls underwent training at a sequential finger tapping task (FTT) and were re-tested on the next morning (after a night with polysomnographic recording) and after another six nights (spent at home). Training and retrieval sessions were performed in a controlled laboratory setting. FTT performance was worse in NC patients than controls at training and at both retrieval sessions and showed a fairly different time course (slower than in controls) of consolidation. Several sleep indices (lower values of stage-2 NREM sleep and SWS) were compatible with a lower effectiveness of sleep for consolidation of motor s...
Osteoporosis International, 2015
ABSTRACT
The Journal of sports medicine and physical fitness, 2010
The aim of the present study was to investigate changes in ghrelin and bone mineral density (BMD)... more The aim of the present study was to investigate changes in ghrelin and bone mineral density (BMD) during further biological maturation after onset of puberty in female adolescent swimmers. Swimmers (n=17) were tested once a year during a two year study period. At the first year, swimmers were at pubertal stages 2 & 3. Fasting plasma ghrelin, leptin, estradiol, insulin-like growth factor-1 (IGF-I) and BMD of the total body, lumbar spine and femoral neck were measured. Ghrelin did not change during the further pubertal development after onset of puberty. No differences in leptin were also seen during the study period. Estradiol and IGF-I were increased during further pubertal development. Total and lumbar spine BMD increased along with further biological maturation. In contrast, further pubertal development had no effect on femoral neck BMD in adolescent female swimmers. Ghrelin was not related to measured BMD values after adjusting for pubertal status at any measurement time. Ghrelin...
International Journal of Sports Medicine, 2009
The aim of our study was to examine the influence of elevated energy expenditure on ghrelin and B... more The aim of our study was to examine the influence of elevated energy expenditure on ghrelin and BMD in young male competitive swimmers advancing from prepubertal to pubertal maturation levels. The study included 19 healthy swimmers (pubertal stage 1) aged between 10 and 12 years. The participants were at the pubertal stages 2 and 3, and 3 and 4 at the second and third year, respectively. Ghrelin was decreased only after the first year. No changes were observed in leptin during the study period. Testosterone increased according to the pubertal development at each measurements. IGF-I was increased at the third measurement compared to the first two measurements. Total and lumbar spine BMDs increased according to the pubertal development in all boys at each measurements, while no changes in femoral neck BMD were observed. Ghrelin was not related to BMD after adjusting for pubertal status. We conclude that ghrelin was decreased at onset of puberty, while no further changes in ghrelin were seen with advancing pubertal stage. Total and lumbar spine BMD increased, while no changes in femoral neck BMD occurred. Ghrelin did not appear to have a direct influence on BMD in young male competitive swimmers.
Journal of Human Sport and Exercise, 2009
... Reference Data: Cicchella A, Jidong L, Jürimäe T, Zini M, Passariello C, Rizzo L, Stefanelli ... more ... Reference Data: Cicchella A, Jidong L, Jürimäe T, Zini M, Passariello C, Rizzo L, Stefanelli C. Anthropometric comparison between young estonian and chinese swimmers. J. Hum.Sport Exerc. 2009; 4(2):154-160. Corresponding author. ...
Medicine & Science in Sports & Exercise, 2010
Medicine & Science in Sports & Exercise, 2007
We examined the effect of regular physical activity on plasma ghrelin concentration after onset o... more We examined the effect of regular physical activity on plasma ghrelin concentration after onset of puberty in girls. In addition, we also examined the association of fasting plasma ghrelin concentration with various plasma biochemical, body composition, and aerobic capacity variables in healthy adolescent girls. Fifty healthy schoolgirls ages 11 to 16 yr were divided either into a physically active (N = 25) or a physically inactive (N = 25) group. The physically active group consisted of swimmers who had trained on an average of 6.2 +/- 2.0 h.wk(-1) for the last 2 yr, whereas the inclusion criterion for the physically inactive group was the participation in physical education classes only. The subjects were matched for age (+/- 1 yr) and body mass index (BMI; +/- 2 kg.m(-2)). Maturation I group (14 matched pairs) included pubertal stages 2 and 3, and maturation II group (11 matched pairs) included pubertal stages 4 and 5. Physically active girls had significantly higher (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) mean plasma ghrelin levels than the physically inactive girls (maturation I: 1152.1 +/- 312.9 vs 877.7 +/- 114.8 pg.mL(-1); maturation II: 1084.0 +/- 252.5 vs 793.4 +/- 164.9 pg.mL(-1)). Plasma ghrelin concentration was negatively related to percent body fat, fat mass, peak oxygen consumption per kilogram of body mass, leptin, estradiol, insulin, and insulin-like growth factor-I (IGF-I) (r &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; -0.298; P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). Multivariate linear regression analysis to determine the predictors of ghrelin concentration using the variables that were significantly associated with ghrelin concentration demonstrated that plasma IGF-I was the most important predictor of plasma ghrelin concentration (beta = -0.396; P = 0.008). Regular physical activity influences plasma ghrelin concentrations in girls with different pubertal maturation levels. Plasma IGF-I concentration seems to be the main determinant of circulating ghrelin in healthy, normal-weight adolescent girls.
Journal of Strength and Conditioning Research, 2006
The aim of this study was to investigate the concepts of electromyographic (EMG) threshold (EMGT)... more The aim of this study was to investigate the concepts of electromyographic (EMG) threshold (EMGT) by integrated EMG (iEMG) signals and neuromuscular fatigue threshold (NMFT) concepts in trained male athletes. Nine competitive national-level male rowers (21.8 +/- 4.4 years; 186.2 +/- 4.6 cm; 79.6 +/- 8.4 kg) took part in this investigation. Subjects were asked to participate in the graded exercise test to volitional exhaustion and 500-, 1,000-, and 2,000-m all-out rowing ergometer tests on a rowing ergometer. During all tests, oxygen consumption parameters, average power, and iEMG of the musculus vastus lateralis were recorded. The second ventilatory threshold (248.9 +/- 26.67 W) and EMGT (258.89 +/- 27.13 W) were not significantly different but were significantly lower than the NMFT (302.25 +/- 45.10 W). During 1,000- and 2,000-m all-out distances, VO(2) increased during the first minute and then leveled on a plateau with a slight decrease at the end of the exercise. Vastus lateralis activity showed a slight increase during all distances that was accompanied by a remarkable increase towards the end of the distance. All measured threshold values were significantly correlated (r &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 0.70; p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) to the rowing ergometer performance characteristics. It was concluded that EMGT is closely related to the aerobic-anaerobic transition phase, because NMFT represents the local fatigue accumulation in the muscle. NMFT indicates the performance capacity of the muscles; therefore, it helps coaches to better predict top athletes&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; performance.
Journal of Endocrinological Investigation, 2009
The aim of the present study was to assess the influence of regular physical activity on plasma g... more The aim of the present study was to assess the influence of regular physical activity on plasma ghrelin concentration in pre-pubertal and pubertal boys. In addition, the impact of ghrelin concentration on bone mineral density (BMD) was examined. In total, 56 healthy schoolboys aged between 10 and 16 yr were divided into the swimming (no.=28) and the control (no.=28) groups. The subjects were matched by age and body mass index (BMI), generating 9 matched pairs in pubertal group I (Tanner stage 1), 11 pairs in group II (Tanner stages 2 and 3), and 8 pairs in group III (Tanner stages 4 and 5). Swimmers in pubertal groups II and III had significantly (both p<0.05) higher mean ghrelin levels than the controls (group II: 1126.8+/-406.0 vs 868.3+/-411.2 pg/ml; group III: 1105.5+/-337.5 vs 850.8+/-306.0 pg/ml, respectively), whereas no difference was seen in the pubertal group I (1230.8+/-386.0 vs 1272.7+/-424.4 pg/ml). Ghrelin was the most important hormonal determinant for total BMD and lumbar apparent volumetric BMD (BMAD) (R2=27.2% and R2=19.8%, respectively) in swimmers, whereas in control boys, plasma IGF-I was the most important hormonal predictor accounting for 41.8% of the variability of total BMD and 20.4% of the variability of lumbar BMAD. In conclusion, ghrelin concentration decreased during puberty in physically inactive boys, while in regularly physically active boys it remained relatively unchanged. Ghrelin appears to be an important hormonal predictor for BMD in physically active boys, while BMD is mostly determined by IGF-I in physically inactive boys.
Journal of Biomechanics, 1994
Acta Paediatrica, 2010
Aim: To evaluate the relationships of visfatin, adiponectin and leptin with bone mineral density ... more Aim: To evaluate the relationships of visfatin, adiponectin and leptin with bone mineral density (BMD) and bone mineral content (BMC) in adolescent female athletes with different training patterns.
Eur J Appl Physiol, 2007
The purpose of the present study was to investigate the use of electromyographic signals (EMG), t... more The purpose of the present study was to investigate the use of electromyographic signals (EMG), to determine the EMG threshold (EMGT) in four lower extremity muscles and to compare these thresholds with the second ventilatory threshold (VT2) in subjects participating in different sports and at different performance levels. Forty-nine subjects (23.8 +/- 5.7 years, 182.7 +/- 5.3 cm, 79.1 +/- 8.6 kg) including eleven cyclists, ten team-handball players, nine kayakers, eight power lifters and eleven controls were investigated utilizing a cycle ergometer. Respiratory gas exchange measures were collected and EMG activity was continuously recorded from four muscles (vastus lateralis, vastus medialis, biceps femoris and gastrocnemius lateralis). The VO(2)max averaged 56.1 +/- 11.1 ml kg(-1) min(-1), the average aerobic power was 348.5 +/- 61.0 W and the corresponding VT2 occurred at 271.4 +/- 64.0 W. The EMGT ranged from 80 to 98% of power output for the different muscles. The VT2 and EMG thresholds from four different muscles were not different. When thresholds were analyzed among different groups of subjects, no significant difference was observed between VT2 and EMGT despite threshold differences between the groups. All four EMGT were significantly related to maximal aerobic power (r = 0.73-0.83) and were highly correlated to each other (r = 0.57-0.88). In conclusion, EMGT can be used to determine the VT2 for individuals independent of sport specificity or performance level.