Exercise Tests in Saddle Horses, 2: The Kinetics of Blood Lactate During Constant Exercise Tests on a Treadmill (original) (raw)
Related papers
Blood lactate concentrations and heart rates of Colombian Paso horses during a field exercise test
Veterinary and Animal Science, 2021
Information on performance indices in Paso horses is scarce. Field exercise tests are necessary to recreate the exertion that occurs during training and competition. To describe blood lactate concentrations and heart rates of untrained Colombian Paso horses (CPHs) in response to a field exercise test. A 30-minutes-long standardized field exercise test was carried out on 11 untrained adult CPHs of both sexes. Blood lactate concentration (BLConc) and heart rate (HR) were measured before, during each step of the test, and at recovery. The BLConc and HR were used to calculate the HR at which a BLConc of 4 mmol/L or anaerobic threshold (HRL 4) was reached. The HR during the field exercise test increased according to the protocol used. The BLConc during the test was variable and, despite having been increasing like the HR, the distribution of the values in each step of the test was remarkably dispersed. The mean blood lactate clearance (BLClear) percentage was 56.3 ± 16, similar in most animals. The HRL 4 was reached at a notably different HR among individuals (132 to 251 bpm). The field exercise test protocol used herein is useful to assess BLConc and HR changes in acute response to exercise in CPHs. It would be useful to evaluate training kinetics with other parameters including cell blood count and muscle enzymes.
Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 2007
Maximal blood lactate steady state concentration (MLSS) and anaerobic threshold (AT) have been shown to accurately predict long distance events performance and training loads, as well, in human athletes. Horse endurance races can take up to 160 km and, in practice, coaches use the 4 mM blood lactate concentration, a human based fixed concentration to establish AT, to predict training loads to horse athletes, what can lead to misleading training loads. The lactate minimum speed (LMS) protocol that consists in an initial elevation in blood lactate level by a high intensity bout of exercise and then establishes an individual equilibrium between lactate production and catabolism during progressive submaximal efforts, has been proposed as a nonfixed lactate concentration, to measure individual AT and at the same time predicts MLSS for human long distance runners and basketball players as well. The purpose of this study was to determine the reliability of the LMS protocol in endurance horse athletes. Five male horses that were engaged on endurance training, for at least 1 year of regular training and competition, were used in this study. Animals were submitted to a 500 m full gallop to determine each blood lactate time to peak (LP) after these determinations, animals were submitted to a progressive 1000 m exercise, starting at 15 km h − 1 to determine LMS, and after LMS determination animals were also submitted to two 10,000 m running, first at LMS and then 10% above LMS to test MLSS accuracy. Mean LP was 8.2 ± 0.7 mM at approximately 5.8 ± 6.09 min, mean LMS was 20.75 ± 2.06 km h − 1 and mean heart rate at LMS was 124.8 ± 4.7 BPM. Blood lactate remained at rest baseline levels during 10,000 m trial at LMS, but reached a six fold significantly raise during 10% above LMS trial after 4000 and 6000 m (p < 0.05) and (p < 0.01) after 8000 and 10,000 m. In conclusion, our adapted LMS protocol for horse athletes proposed here seems to be a reliable method to state endurance horse athletes LT and MLSS.
Blood lactate threshold reflects glucose responses in horses submitted to incremental exercise test
Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 2008
The energy necessary for muscle contraction is obtained from the hydrolysis of ATP, releasing inorganic phosphate. ATP can be furnished by phosphocreatine, glucose, glycogen, amino acids and free fatty acids. The production of ATP is much more efficient in the presence of oxygen than in its absence. The anaerobic metabolism of glucose, although less efficient than the aerobic, represents an important and rapid mechanism of energy generation. Several factors regulate the activity of the glycolytic pathway, such as the availability of oxygen, lactate dehydrogenase (LDH) activity and the ATP/ADP ratio. As this ratio decreases the anaerobic glycolysis is stimulated, increasing the production of pyruvate and lactate.
Frontiers in Physiology, 2022
There is a great need for objective external training load prescription and performance capacity evaluation in equestrian disciplines. Therefore, reliable standardised exercise tests (SETs) are needed. Classic SETs require maximum intensities with associated risks to deduce training loads from pre-described cut-off values. The lactate minimum speed (LMS) test could be a valuable alternative. Our aim was to compare new performance parameters of a modified LMS-test with those of an incremental SET, to assess the effect of training on LMS-test parameters and curve-shape, and to identify the optimal mathematical approach for LMS-curve parameters. Six untrained standardbred mares (3–4 years) performed a SET and LMS-test at the start and end of the 8-week harness training. The SET-protocol contains 5 increments (4 km/h; 3 min/step). The LMS-test started with a 3-min trot at 36–40 km/h [until blood lactate (BL) > 5 mmol/L] followed by 8 incremental steps (2 km/h; 3 min/step). The maximu...
Journal of Equine Veterinary Science, 2014
Modifications of some serum electrolyte concentration during two international *** show jumping competition performed in two consecutive weekends were evaluated. Serum sodium (Na), chloride (Cl), magnesium (Mg), potassium (K), phosphorous (P), calcium (Ca), iron (Fe), and blood lactate on 14 well-trained Italian saddle horses were assessed. Blood samples were collected before the beginning of the competition (T0B), within 10 minutes after the end of race (R1, R2, and R3), and on the day after competition (T0R). The same procedure was followed on the second weekend (R4, R5, R6, and T1R). One-way repeated measures analysis of variance was applied on collected data, and a significant effect on sampling time (P < .05) on all parameters studied was found. These results suggest that serum electrolytes and blood lactate concentration are responsive to intense exercise and could be considered an important factor for a correct management training's planning.
Distribution of lactate in plasma and erythrocytes during and after exercise in horses
The British veterinary journal
The distribution of lactate between red blood cells (RBC) and plasma was examined at rest, during exercise and 30 min after exercise in six Standardbred horses. Lactate and water concentrations were measured in blood and plasma samples collected prior to exercise, during the last 15 s of each step of an incremental exercise test and at 5 min intervals during the first 30 min after exercise. The mean ratio of RBC lactate concentration (RBCLa) to plasma lactate concentration (PLa) prior to exercise was 1.02 +/- 0.34. Haemoconcentration during exercise was associated with more rapid accumulation of lactate in plasma than in RBCs. Mean whole blood lactate concentration (BLa) was only 59% of PLa in samples collected during exercise. BLa was highly correlated with PLa during exercise (r = 0.98; P < 0.001), but individual PLa values differed from predicted BLa values by up to 2.1 mmol l-1 when PLa exceeded 8 mmol l-1. At each exercise speed and time after exercise there was a large vari...
Equine and Comparative Exercise Physiology, 2004
The objective of this experiment was to compare the physiological changes that occurred in horses competing in the cross-country portion of Training, Preliminary and Intermediate horse trials. The hypothesis was that temperature (T), heart rate (HR), respiratory rate (RR), and on-site acid–base and electrolyte monitoring would allow differentiation between difficulty levels in horse trials. Sixteen client-owned horses competing at the Trojan-Horse Spring Horse Trials in Cave Creek, Arizona, USA, were studied. T, HR, RR and anaerobic lithium-heparinized jugular venous samples were obtained before, and 1–2 min after, cross-country exercise. Samples were analysed for blood gases (body temperature-corrected) and concentrations of sodium ([Na+]), potassium ([K+]), chloride ([Cl−]), ionized calcium ([Ca2+]i), blood urea nitrogen ([BUN]) and glucose ([GLC]) using a point-of-care analyser. Results were compared using analysis of variance with the level of significance set at P<0.05. In a...
2010
Rivero JL, Ruz A, Martí-Korff S, Estepa JC, Aguilera-Tejero E, Werkman J, Sobotta M, Lindner A. Effects of intensity and duration of exercise on muscular responses to training of thoroughbred racehorses. This study examined the effects of the intensity and duration of exercise on the nature and magnitude of training adaptations in muscle of adolescent (2-3 yr old) racehorses. Six thoroughbreds that had been pretrained for 2 mo performed six consecutive conditioning programs of varying lactate-guided intensities [velocities eliciting blood lactate concentrations of 2.5 mmol/l (v2.5) and 4 mmol/l (v4), respectively] and durations (5, 15, 25 min). Pre-and posttraining gluteus muscle biopsies were analyzed for myosin heavy chain content, fiber-type composition, fiber size, capillarization, and fiber histochemical oxidative and glycolytic capabilities. Although training adaptations were similar in nature, they varied greatly in magnitude among the different training protocols. Overall, the use of v4 as the exercise intensity for 25 min elicited the most consistent training adaptations in muscle, whereas the minimal training stimulus that evoked any significant change was identified with exercises of 15 min at v2.5. Within this range, muscular adaptations showed significant trends to be proportional to the exercise load of specific training programs. Taken together, these data suggest that muscular adaptations to training in horses occur on a continuum that is based on the exercise intensity and duration of training. The practical implications of this study are that exercises for 15 to 25 min/day at velocities between v2.5 and v4 can improve in the short term (3 wk) the muscular stamina in thoroughbreds. However, exercises of 5-15 min at v4 are necessary to enhance muscular features related to strength (hypertrophy).
Speed, heart rate, lactate and uric acid alterations led to reduced performance and hamper the health status of endurance horses. The aim of this study was to investigate on the effects of speed, heart rate, lactate and uric acid on the performance of Arabian horses during a 120 km endurance race. One hundred and eighty four Arabian endurance horses were physically examined and blood samples were collected post-race. After physical examination, the metabolic disordered (MD; n=130) and successfully completed (SC; n = 54) endurance horses were recognized. T-test was used for the analysis. The mean values of speed, heart rate, lactate and uric acid were significantly different (P<0.0001) between the MD and SC endurance horses. In conclusion, alterations in speed, heart rate, blood lactate and uric acid led to poor performance and encumbered the health status of endurance horses. Speed, heart rate, blood lactate and uric acid could be used to appraise performance and health status in endurance horses during training and endurance events.
Comparative Exercise Physiology, 2019
Objective performance monitoring in eventing horses is rare as the implementation of standardised exercise tests is commonly perceived to interfere with the daily training routine. The validity of performance parameters derived from GPS data, heart rate (HR) and post exercise blood lactate concentration (LAC) measured during usual training sessions should therefore be evaluated. Velocity (V), HR and post exercise LAC recorded during 172 interval training sessions in 30 horses were retrospectively analysed. Linear regression of HR, averaged over retrospectively defined speed ranges, was used to calculate the V at HRs of 150 (V150) and 200 (V200) beats/min. A single exponential regression model, fitted to LAC in relation to HR values from the whole group of horses, was used to predict LAC for each horse’s individual HR value and to calculate the difference between measured and predicted LAC (LACdiff). Recovery HRs were derived from bi-exponential regression of HR decrease after exerci...