Lactate-guided conditioning program using variable exercise intensities improves fitness and alters muscle enzyme activity but not inflammatory response in horses

2016 ◽  
Vol 12 (4) ◽  
pp. 183-192
Author(s):  
A.L. Fisher ◽  
H.M. Greene ◽  
R.J. Talmadge ◽  
Y.S. Nout-Lomas

Blood lactate concentration ([LA]) response to exercise challenges can be used to assess fitness in horses. Most equine conditioning programs (CP) that have been studied are based on regular bouts of exercise of similar to increasing levels of intensity. We hypothesised that a lactate-guided CP implementing 2× weekly short-duration high-intensity exercise bouts and 1× weekly low-intensity longer-duration exercise bout effectively increases fitness in horses. Six untrained adult horses followed a 12 week CP that consisted of 2× weekly exercise on an equine treadmill (6% incline) for 25 min at a velocity at which [LA] was 4.0 mmol/l (VLA4.0) and 1× weekly for 45 min at a velocity at which [LA] was 2.5 mmol/l (VLA2.5). VLA2.5 and VLA4.0 were determined by incremental-step standardised-exercisetest (SET) before the CP and adjusted every 3 weeks. Blood was collected for [LA], creatine kinase (CK), aspartate aminotransferase (AST), serum amyloid A (SAA), and fibrinogen (Fb) before each speed increase and 30 min, 2, 4, and 24 h after termination of the SET, when [LA] was ≥4.0 mmol/l. Repeated-measures ANOVA was used for analysis. During each SET horses showed increases in heart rate (P<0.0001), packed cell volume (P=0.003), and [LA] (P=0.002). Throughout the CP, VLA2.5 increased from 5.6±0.2 to 6.7±0.3 m/s (P<0.05) and VLA4.0 increased from 6.0±0.2 to 7.4±0.3 m/s (P<0.01). CK, AST, SAA, and Fb did not increase following submaximal exercise. CK and AST activity were attenuated throughout the 12 week CP (P<0.05). This lactate-guided CP was effective at increasing fitness based on achieving higher speeds during the SETs and did not appear to have deleterious effects on the horses’ muscular system or inflammatory state.

2009 ◽  
Vol 19 (4) ◽  
pp. 355-365 ◽  
Author(s):  
Raul Bescós ◽  
Carlos Gonzalez-Haro ◽  
Pere Pujol ◽  
Franchek Drobnic ◽  
Eulalia Alonso ◽  
...  

To assess the effect of diet enrichment with L-arginine or supplementation at high doses on physiological adaptation during exercise, 9 athletes followed 3 different diets, each over 3 consecutive days, with a wash-out period of 4 d between training sessions: control diet (CD), 5.5 ± 0.3 g/d of L-arginine; Diet 1 (rich in L-arginine food), 9.0 ± 1.1 g/d of L-arginine; and Diet 2 (the same as CD but including an oral supplement of 15 g/d), 20.5 ± 0.3 g/d of L-arginine. Plasma nitrate levels of each participant were determined on the day after each treatment. Participants performed a submaximal treadmill test (initial speed 10–11 km/hr, work increments 1 km/hr every 4 min until 85–90% VO2max, and passive recovery periods of 2 min). Oxygen uptake and heart rate were monitored throughout the test. Blood lactate concentration ([La−]b) was determined at the end of each stage. Repeated-measures ANOVA and paired Student’s t tests were used to compare the various physiological parameters between diets. The level of significance was set at p < .05. [La−]b showed a significant effect at the 5-min time point between CD and Diet 2 (CD 3.0 ± 0.5 mM, Diet 2 2.5 ± 0.5 mM, p = .03), but this tendency was not found at higher exercise intensities. No significant differences were observed in any of the cardiorespiratory or plasma nitrate levels. In conclusion, dietary L-arginine intake on the days preceding the test does not improve physiological parameters during exercise.


1975 ◽  
Vol 38 (5) ◽  
pp. 763-767 ◽  
Author(s):  
J. Karlsson ◽  
F. Bonde-Petersen ◽  
J. Henriksson ◽  
H. G. Knuttgen

The ability of additional muscles to perform after certain other muscles of the body had been exercised to exhaustion was studied in three male subjects. Exhaustive exercise was performed in two series: series L-A, a bout of leg exercise preceded a bout of arm exercise; series A-L, arm preceded leg (6-min recovery between bouts). Biopsies were taken during the course of each experiment from both the deltoideus and vastus lateralis muscles for determination of ATP, creatine phosphate, lactate, and pyruvate. Exhaustive exercise led to marked elevations in lactate and decreases in ATP and CP in exercised muscle and marked increases in blood lactate concentration. Similar changes, especially in lactate, were observed during and after the first exercise bout in nonexercised muscle. When arm or leg exercise was performed as the second bout, decreases in performance time were observed as compared to performance as the initial bout. It is suggested that the performance potential of muscle is decreased because of internal changes elicited by elevated blood lactate and/or blood H+ concentrations brought about by other muscle groups previously exercised to exhaustion.


2013 ◽  
Vol 9 (1) ◽  
pp. 33-41 ◽  
Author(s):  
R. Munk ◽  
S. Møller ◽  
A. Lindner

Studies examining the effect of conditioning programs to improve the fitness of horses used in show jumping (Show Jumpers) are not available. Therefore, the effects of conditioning with 3 different interval type exercises were examined on 20 Show Jumpers divided into 3 groups matched by age and jumping performance level. Horses participated in 2 conditioning periods (CP) each of 6 weeks separated by 6 weeks without interval exercise. Training during a CP was the same for all horses but for one specific interval type exercise bout every 5th day. The specific interval exercise bouts were termed Gallop (n=13), Sprint (n=14) and Jump (n=13) and consisted of 4 times 90 s sessions each: Gallop were runs at the heart rate producing a blood lactate concentration (LA) of 4 mmol/l, Sprint were accelerations on the long-sides and decelerations in the short-sides of an arena, and Jump consisted of jumping obstacles of increasing height. Horses were submitted to 3 different standardised exercise tests (SET) before and after each CP: SETv4 (v4 is the speed at which a blood LA of 4 mmol/l is determined), SETjump (16 one jump obstacles in an elliptical course) and SETcourse (11 obstacles at the level of individually adjusted maximal degrees of difficulty). SETv4 showed that the v4 increased more in the Gallop (n=7) and Jump groups (n=7) than in the Sprint group (n=6). These results are based on fewer horses than the others because weather conditions did not allow for running this SET after the second period of conditioning. SETjump showed that blood LA and the level of fatigue estimated by the rider decreased after all interval type exercise bouts. A subjective fatigue score used by the rider in SETcourse improved regardless of the conditioning type of the horses, while their jumping technique improved with Gallop and Jump interval exercise only. Also the blood LA after SETcourse was lower after conditioning with Gallop and Jump interval exercise and the jumping technique improved according to an experienced independent observer in horses conditioned with Gallop, remained the same with Jump and decreased with Sprint interval exercise. In conclusion, all interval type exercise bouts examined improved parameters of fitness, but Gallop and Jump interval exercise improved more parameters than Sprint interval exercise bouts (v4, blood LA and fatigue level assessed by the rider after Gallop and Jump interval exercise; blood LA and fatigue level assessed by the rider after Sprint exercise), and Gallop as well as Jump interval exercise bouts improved the jumping technique too (as assessed by the rider and the independent observer for Gallop, and by the rider only after Jump interval exercise).


1994 ◽  
Vol 76 (2) ◽  
pp. 610-615 ◽  
Author(s):  
R. S. Mazzeo ◽  
G. A. Brooks ◽  
G. E. Butterfield ◽  
A. Cymerman ◽  
A. C. Roberts ◽  
...  

We examined the extent to which epinephrine influences blood lactate adjustments to exercise during both acute (AC) and chronic (CH) high-altitude exposure. Eleven male sea level residents were divided into a control group (n = 5) receiving a placebo or a drug group (n = 6) receiving 240 mg/day of propranolol. All subjects were studied at rest and during 45 min of submaximal exercise (approximately 50% of sea level maximal O2 uptake) at sea level (SL) and within 4 h of exposure to and after 3 wk residence at 4,300 m (summit of Pikes Peak). Blood samples were collected from the femoral artery for epinephrine and lactate concentration. Exercising blood lactate concentration was significantly different across all altitude conditions such that AC > CH > SL (P < 0.05). For a given arterial O2 saturation, mean exercising blood lactates were lower for the beta-blocked group compared with controls; however, both groups demonstrated similar patterns across all conditions. Epinephrine levels during exercise followed a similar pattern to that of lactate, averaging 0.67, 0.43, and 0.29 ng/ml for AC, CH, and SL, respectively. The correlation between lactate and epinephrine was 0.93 and 0.84 for control and beta-blocked subjects, respectively. Whereas during exercise epinephrine was consistently higher for the beta-blocked group than controls, this difference was only significant during CH exposure. The epinephrine response was related to the extent of hypoxia in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)


1993 ◽  
Vol 75 (2) ◽  
pp. 870-878 ◽  
Author(s):  
D. L. Thompson ◽  
J. Y. Weltman ◽  
A. D. Rogol ◽  
D. L. Metzger ◽  
J. D. Veldhuis ◽  
...  

Cholinergic and opioid pathways have been implicated as mediators of the increased growth hormone (GH) release observed during exercise. This study compared the GH responses induced by a moderate-intensity exercise bout during treatment with placebo (Plac), the opioid receptor antagonist naltrexone (Nalt), the indirect cholinergic agonist pyridostigmine (PD), or a combination of the two drugs (P + N). Ten active males served as subjects (age, 25.1 +/- 0.6 yr; wt, 79.7 +/- 2.5 kg; % body fat, 14.9 +/- 1.4; peak oxygen consumption, 46.2 +/- 2.7 ml.kg-1 x min-1). Blood samples were drawn at 5-min intervals during the 4.5-h testing period to determine the GH concentration. The testing period was divided as follows: 0600–700 h = baseline, 0700–0800 h = preexercise, 0800–0830 h = exercise, and 0830–1030 h = recovery. Drugs were administered 1 h before exercise (at 0700 h). Exercise consisted of 30 min of cycling at an individualized work load previously found to elicit a blood lactate concentration of 2.5 mM. Heart rate, oxygen consumption, blood lactate, and blood glucose were measured throughout the exercise period. Results indicated that neither the resting GH concentration nor the metabolic parameters during exercise were altered by the treatments. Peak serum GH concentration was not significantly altered by the treatments (range 7.3 +/- 2.0 to 12.6 +/- 4.4 micrograms/l).(ABSTRACT TRUNCATED AT 250 WORDS)


2021 ◽  
Vol 77 (1) ◽  
pp. 169-179
Author(s):  
Seifeddine Brini ◽  
Anne Delextrat ◽  
Anissa Bouassida

Abstract Repeated sprint ability (RSA) with five changes of direction was well admitted to replicate real basketball game situations, but the additional changes of direction may affect some fundamental skills and performances in basketball. The aim of this study was to investigate the effects of RSA with one vs. five changes of direction (IRSA5COD) on squat jump (SJ), five jump test (FJT) and three point shot (3PS) performances in male basketball players. Sixteen participants (23.4 ± 2.3 years; 1.86 ± 0.10 m; 77.8 ± 7.7 kg) randomly performed eight testing sessions consisting of either RSA (10 repetitions of (15 m + 15 m)) or IRSA5COD (10 repetitions of (5 m + 5 m + 5 m + 5 m + 5 m + 5 m)) performed alone or immediately followed by the SJ, FJT or 3PS. The heart rate (HR) and ratings of perceived exertion (RPE) were continuously recorded, while blood lactate concentration was measured post-tests. Differences between RSA and IRSA5COD were evaluated by a Student t-test for paired samples, while analyses of variance (ANOVAs) with repeated measures assessed differences in SJ, FJT and 3PS performance between baseline, post-RSA and post-IRSA5COD. A significantly poorer FJT performance post-RSA was shown compared to baseline (7.47 ± 0.47 vs.7.54 ± 0.47 m, p = 0.01) and post-IRSA 5COD (7.47 ± 0.47 vs. 7.56 ± 0.49%, p = 0.048). Significantly lower 3PS accuracy was also observed post-IRSA 5COD compared to baseline (41.3 ± 3.1 vs.53.1 ± 2.8%, p = 0.003) and post-RSA (41.3 ± 3.1 vs. 48.1 ± 3.7%, p = 0.033). These results suggest that jump performance required for crucial actions such as lay-ups is negatively affected by longer sprints (15-m) with few changes of direction, while 3PS accuracy is impaired by shorter sprints with many changes of direction. These situations should be replicated when training these particular abilities to optimize training adaptations.


2020 ◽  
Vol 73 (1) ◽  
pp. 33-44
Author(s):  
Gustavo Ferreira Pedrosa ◽  
Sandra Carvalho Machado ◽  
Rodrigo César Ribeiro Diniz ◽  
Lucas Túlio de Lacerda ◽  
Hugo Cesar Martins-Costa ◽  
...  

AbstractThis study compared the electromyographic response, the blood lactate concentration (BLC), and the maximum number of repetitions (MNR) between protocols of different concentric/eccentric duration taken to muscle failure. This comparison may help to understand how different concentric/eccentric duration may influence performance and the central and metabolic responses in trained men. Seventeen strength-trained men performed two protocols in a counterbalanced design. Three sets of the Smith bench press exercise were performed to failure at 60% of the one-repetition maximum (1RM) using each protocol (4-s concentric/2-s eccentric [4 s: 2 s]; and 2-s concentric/4-s eccentric [2 s: 4 s]). The normalized root mean square (EMGRMS) and the mean frequency (EMGMF) of the electromyographic signals for the pectoralis major and the triceps brachii were compared in the first, middle, and last repetitions. The BLC was assessed at rest, during and after the test sessions. To compare the EMG and BLC, a 3-way ANOVA with repeated measures with a post hoc Tukey’s test was used. To compare the MNR performed across the sets, an ANOVA-type rank test with the Dunn’s post hoc test was used. The ANOVA indicated a greater EMGRMS for Protocol 4 s: 2 s in the pectoralis major and a lower EMGMF for Protocol 4 s: 2 s in the triceps brachii at the middle and last repetitions. Both protocols increased the EMGRMS and decreased the EMGMF across repetitions. Despite the results show different levels of activation and neuromuscular fatigue between protocols, the BLC and the MNR were similar.


Author(s):  
Nathalie V. Kirby ◽  
Samuel J. E. Lucas ◽  
Oliver J. Armstrong ◽  
Samuel R. Weaver ◽  
Rebekah A. I. Lucas

Abstract Purpose This study investigated whether intermittent post-exercise sauna bathing across three-weeks endurance training improves exercise heat tolerance and exercise performance markers in temperate conditions, compared to endurance training alone. The subsidiary aim was to determine whether exercise-heat tolerance would further improve following 7-Weeks post-exercise sauna bathing. Methods Twenty middle-distance runners (13 female; mean ± SD, age 20 ± 2 years, $$V$$ V O2max 56.1 ± 8.7 ml kg−1 min−1) performed a running heat tolerance test (30-min, 9 km h−1/2% gradient, 40 °C/40%RH; HTT) and temperate (18 °C) exercise tests (maximal aerobic capacity [$$V$$ V O2max], speed at 4 mmol L−1 blood lactate concentration ([La−]) before (Pre) and following three-weeks (3-Weeks) normal training (CON; n = 8) or normal training with 28 ± 2 min post-exercise sauna bathing (101–108 °C, 5–10%RH) 3 ± 1 times per week (SAUNA; n = 12). Changes from Pre to 3-Weeks were compared between-groups using an analysis of co-variance. Six SAUNA participants continued the intervention for 7 weeks, completing an additional HTT (7-Weeks; data compared using a one-way repeated-measures analysis of variance). Results During the HTT, SAUNA reduced peak rectal temperature (Trec; − 0.2 °C), skin temperature (− 0.8 °C), and heart rate (− 11 beats min−1) more than CON at 3-Weeks compared to Pre (all p < 0.05). SAUNA also improved $$V$$ V O2max (+ 0.27 L−1 min−1; p = 0.02) and speed at 4 mmol L−1 [La−] (+ 0.6 km h−1; p = 0.01) more than CON at 3-Weeks compared to Pre. Only peak Trec (− 0.1 °C; p = 0.03 decreased further from 3-Weeks to 7-Weeks in SAUNA (other physiological variables p > 0.05). Conclusions Three-weeks post-exercise sauna bathing is an effective and pragmatic method of heat acclimation, and an effective ergogenic aid. Extending the intervention to seven weeks only marginally improved Trec.


2012 ◽  
Vol 31 (1) ◽  
pp. 89-96 ◽  
Author(s):  
Yusuf Köklü

A Comparison Of Physiological Responses To Various Intermittent And Continuous Small-Sided Games In Young Soccer Players The purpose of this study was to investigate physiological responses to various intermittent and continuous small-sided games (SSGs) - including 2-a-side, 3-a-side, and 4-a-side games - in young soccer players. Twenty soccer players (average age 16.6±0.5 years; mean body height 176.2±4.6 cm; mean body mass 65.9±5.6 kg) voluntarily participated in this study. The subjects underwent anthropometric measurements followed by the YoYo intermittent recovery test. Then, they played intermittent (SSGint) and continuous (SSGcon) 2-a-side, 3-a-side, and 4-a-side soccer-specific SSGs in random order at 2-day intervals. Paired t-tests were used to assess differences between the training regimens (intermittent and continuous) in terms of heart rate (HR), percentage of maximum HR (%HRmax), and blood lactate concentration (LA). The differences in LA, HR and %HRmax between the 2-a-side, 3-a-side and 4-a-side SSGint or the 2-a-side, 3-a-side and 4-a-side SSGcon were identified using a one-way analysis of variance with repeated measures. The results demonstrated that the 3-a-side SSGint and SSGcon measurements were significantly higher than the 2-a-side and 4-a-side games in terms of HR and %HRmax, whereas the 2-a-side SSGint and SSGcon resulted in higher LA responses compared to other SSG types. The study results also demonstrated that SSGint and SSGcon are similar in terms of physiological responses except for 2-a-side game LA responses. The results of this study suggest that both SSGint and SSGcon could be used for the physiological adaptations required for soccer specific aerobic endurance.


Author(s):  
Daniel Büchel ◽  
Øyvind Sandbakk ◽  
Jochen Baumeister

Abstract Purpose Exhaustive cardiovascular load can affect neural processing and is associated with decreases in sensorimotor performance. The purpose of this study was to explore intensity-dependent modulations in brain network efficiency in response to treadmill running assessed from resting-state electroencephalography (EEG) measures. Methods Sixteen trained participants were tested for individual peak oxygen uptake (VO2 peak) and performed an incremental treadmill exercise at 50% (10 min), 70% (10 min) and 90% speed VO2 peak (all-out) followed by cool-down running and active recovery. Before the experiment and after each stage, borg scale (BS), blood lactate concentration (BLa), resting heartrate (HRrest) and 64-channel EEG resting state were assessed. To analyze network efficiency, graph theory was applied to derive small world index (SWI) from EEG data in theta, alpha-1 and alpha-2 frequency bands. Results Analysis of variance for repeated measures revealed significant main effects for intensity on BS, BLa, HRrest and SWI. While BS, BLa and HRrest indicated maxima after all-out, SWI showed a reduction in the theta network after all-out. Conclusion Our explorative approach suggests intensity-dependent modulations of resting-state brain networks, since exhaustive exercise temporarily reduces brain network efficiency. Resting-state network assessment may prospectively play a role in training monitoring by displaying the readiness and efficiency of the central nervous system in different training situations.


Sign in / Sign up

Export Citation Format

Share Document