Effect of training on muscle metabolism during treadmill sprinting

1989 ◽  
Vol 67 (6) ◽  
pp. 2376-2382 ◽  
Author(s):  
M. E. Nevill ◽  
L. H. Boobis ◽  
S. Brooks ◽  
C. Williams

Sixteen subjects volunteered for the study and were divided into a control (4 males and 4 females) and experimental group (4 males and 4 females, who undertook 8 wk of sprint training). All subjects completed a maximal 30-s sprint on a nonmotorized treadmill and a 2-min run on a motorized treadmill at a speed designed to elicit 110% of maximum oxygen uptake (110% run) before and after the period of training. Muscle biopsies were taken from vastus lateralis at rest and immediately after exercise. The metabolic responses to the 110% run were unchanged over the 8-wk period. However, sprint training resulted in a 12% (P less than 0.05) and 6% (NS) improvement in peak and mean power output, respectively, during the 30-s sprint test. This improvement in sprint performance was accompanied by an increase in the postexercise muscle lactate (86.0 +/- 26.4 vs. 103.6 +/- 24.6 mmol/kg dry wt, P less than 0.05) and plasma norepinephrine concentrations (10.4 +/- 5.4 vs. 12.1 +/- 5.3 nmol/l, P less than 0.05) and by a decrease in the postexercise blood pH (7.17 +/- 0.11 vs. 7.09 +/- 0.11, P less than 0.05). There was, however, no change in skeletal muscle buffering capacity as measured by the homogenate technique (67.6 +/- 6.5 vs. 71.2 +/- 4.5 Slykes, NS).

1986 ◽  
Vol 61 (1) ◽  
pp. 54-60 ◽  
Author(s):  
M. E. Cheetham ◽  
L. H. Boobis ◽  
S. Brooks ◽  
C. Williams

Biopsy samples were obtained from vastus lateralis of eight female subjects before and after a maximal 30-s sprint on a nonmotorized treadmill and were analyzed for glycogen, phosphagens, and glycolytic intermediates. Peak power output averaged 534.4 +/- 85.0 W and was decreased by 50 +/- 10% at the end of the sprint. Glycogen, phosphocreatine, and ATP were decreased by 25, 64, and 37%, respectively. The glycolytic intermediates above phosphofructokinase increased approximately 13-fold, whereas fructose 1,6-diphosphate and triose phosphates only increased 4- and 2-fold. Muscle pyruvate and lactate were increased 19 and 29 times. After 3 min recovery, blood pH was decreased by 0.24 units and plasma epinephrine and norepinephrine increased from 0.3 +/- 0.2 nmol/l and 2.7 +/- 0.8 nmol/l at rest to 1.3 +/- 0.8 nmol/l and 11.7 +/- 6.6 nmol/l. A significant correlation was found between the changes in plasma catecholamines and estimated ATP production from glycolysis (norepinephrine, glycolysis r = 0.78, P less than 0.05; epinephrine, glycolysis r = 0.75, P less than 0.05) and between postexercise capillary lactate and muscle lactate concentrations (r = 0.82, P less than 0.05). The study demonstrated that a significant reduction in ATP occurs during maximal dynamic exercise in humans. The marked metabolic changes caused by the treadmill sprint and its close simulation of free running makes it a valuable test for examining the factors that limit performance and the etiology of fatigue during brief maximal exercise.


1998 ◽  
Vol 275 (1) ◽  
pp. E132-E139 ◽  
Author(s):  
C. T. Putman ◽  
N. L. Jones ◽  
E. Hultman ◽  
M. G. Hollidge-Horvat ◽  
A. Bonen ◽  
...  

Muscle metabolism, including the role of pyruvate dehydrogenase (PDH) in muscle lactate (Lac−) production, was examined during incremental exercise before and after 7 days of submaximal training on a cycle ergometer [2 h daily at 60% peak O2 uptake (V˙o 2 max)]. Subjects were studied at rest and during continuous steady-state cycling at three stages (15 min each): 30, 65, and 75% of the pretraining V˙o 2 max. Blood was sampled from brachial artery and femoral vein, and leg blood flow was measured by thermodilution. Biopsies of the vastus lateralis were obtained at rest and during steady-state exercise at the end of each stage. V˙o 2 max, leg O2 uptake, and the maximum activities of citrate synthase and PDH were not altered by training; muscle glycogen concentration was higher. During rest and cycling at 30% V˙o 2 max, muscle Lac− concentration ([Lac−]) and leg efflux were similar. At 65%V˙o 2 max, muscle [Lac−] was lower (11.9 ± 3.2 vs. 20.0 ± 5.8 mmol/kg dry wt) and Lac− efflux was less [−0.22 ± 0.24 (one leg) vs. 1.42 ± 0.33 mmol/min] after training. Similarly, at 75%V˙o 2 max, lower muscle [Lac−] (17.2 ± 4.4 vs. 45.2 ± 6.6 mmol/kg dry wt) accompanied less release (0.41 ± 0.53 vs. 1.32 ± 0.65 mmol/min) after training. PDH in its active form (PDHa) was not different between conditions. Calculated pyruvate production at 75%V˙o 2 max fell by 33%, pyruvate reduction to lactate fell by 59%, and pyruvate oxidation fell by 24% compared with before training. Muscle contents of coenzyme A and phosphocreatine were higher during exercise after training. Lower muscle lactate production after training resulted from improved matching of glycolytic and PDHafluxes, independently of changes in muscle O2 consumption, and was associated with greater phosphorylation potential.


2000 ◽  
Vol 279 (1) ◽  
pp. R152-R160 ◽  
Author(s):  
Niels Ørtenblad ◽  
Per K. Lunde ◽  
Klaus Levin ◽  
Jesper L. Andersen ◽  
Preben K. Pedersen

To evaluate the effect of intermittent sprint training on sarcoplasmic reticulum (SR) function, nine young men performed a 5 wk high-intensity intermittent bicycle training, and six served as controls. SR function was evaluated from resting vastus lateralis muscle biopsies, before and after the training period. Intermittent sprint performance (ten 8-s all-out periods alternating with 32-s recovery) was enhanced 12% ( P < 0.01) after training. The 5-wk sprint training induced a significantly higher ( P < 0.05) peak rate of AgNO3-stimulated Ca2+ release from 709 (range 560–877; before) to 774 (596–977) arbitrary units Ca2+ ⋅ g protein− 1 ⋅ min− 1(after). The relative SR density of functional ryanodine receptors (RyR) remained unchanged after training; there was, however, a 48% ( P < 0.05) increase in total number of RyR. No significant differences in Ca2+ uptake rate and Ca2+-ATPase capacity were observed following the training, despite that the relative density of Ca2+-ATPase isoforms SERCA1 and SERCA2 had increased 41% and 55%, respectively ( P < 0.05). These data suggest that high-intensity training induces an enhanced peak SR Ca2+ release, due to an enhanced total volume of SR, whereas SR Ca2+ sequestration function is not altered.


Author(s):  
Mojtaba Kaviani ◽  
Keely Shaw ◽  
Philip D. Chilibeck

Background: Creatine monohydrate is a nutritional supplement often consumed by athletes in anaerobic sports. Creatine is naturally found in most meat products; therefore, vegetarians have reduced creatine stores and may benefit from supplementation. Objective: to determine the effects of creatine supplementation on vegetarians. Data sources: PubMed and SPORTDiscus. Eligibility criteria: Randomized controlled trials (parallel group, cross-over studies) or prospective studies. Participants: Vegetarians. Intervention: Creatine supplementation. Study appraisal and synthesis: A total of 64 records were identified, and eleven full-text articles (covering nine studies) were included in this systematic review. Results: Creatine supplementation in vegetarians increased total creatine, creatine, and phosphocreatine concentrations in vastus lateralis and gastrocnemius muscle, plasma, and red blood cells, often to levels greater than omnivores. Creatine supplementation had no effect on brain levels of phosphocreatine. Creatine supplementation increased lean tissue mass, type II fiber area, insulin-like growth factor-1, muscular strength, muscular endurance, Wingate mean power output, and brain function (memory and intelligence) in vegetarian participants. Studies were mixed on whether creatine supplementation improved exercise performance in vegetarians to a greater extent compared to omnivores. Limitations: Studies that were reviewed had moderate–high risk of bias. Conclusions: Overall, it appears vegetarian athletes are likely to benefit from creatine supplementation.


1992 ◽  
Vol 2 (4) ◽  
pp. 307-316 ◽  
Author(s):  
Matthew D. Vukovich ◽  
Rick L. Sharp ◽  
Douglas S. King ◽  
Kellie Kershishnik

Eleven subjects performed a graded exercise test after 1 week of protein supplementation (PRO) or glucose polymer placebo (CON), randomly assigned in a double blind fashion. The exercise consisted of 3-min graded exercise bouts separated by 10 min of active recovery at zero pedal resistance. Subjects then performed a 30-sec Wingate test (WIN) to assess performance during supramaximal exercise. Blood samples were obtained in the last 15 sec of each exercise and recovery period. PRO resulted in a decrease in blood lactate following 120%and WIN, an increase in blood alanine at all time points, and lower postexercise muscle lactate and glycogen. Resting muscle GPT activity was 47% higher during the PRO trial. Mean power output during the WIN did not differ between PRO and CON. The WIN fatigue index was not significantly different between PRO and CON. The increased alanine may reflect increased transamination of pyruvate, thereby reducing the accumulation of lactate, which in turn had a marginal effect on performance during supramaximal exercise.


2004 ◽  
Vol 97 (6) ◽  
pp. 2148-2153 ◽  
Author(s):  
Paul J. LeBlanc ◽  
Krista R. Howarth ◽  
Martin J. Gibala ◽  
George J. F. Heigenhauser

This is the first study to examine the effects of endurance training on the activation state of glycogen phosphorylase (Phos) and pyruvate dehydrogenase (PDH) in human skeletal muscle during exercise. We hypothesized that 7 wk of endurance training (Tr) would result in a posttransformationally regulated decrease in flux through Phos and an attenuated activation of PDH during exercise due to alterations in key allosteric modulators of these important enzymes. Eight healthy men (22 ± 1 yr) cycled to exhaustion at the same absolute workload (206 ± 5 W; ∼80% of initial maximal oxygen uptake) before and after Tr. Muscle biopsies (vastus lateralis) were obtained at rest and after 5 and 15 min of exercise. Fifteen minutes of exercise post-Tr resulted in an attenuated activation of PDH (pre-Tr: 3.75 ± 0.48 vs. post-Tr: 2.65 ± 0.38 mmol·min−1·kg wet wt−1), possibly due in part to lower pyruvate content (pre-Tr: 0.94 ± 0.14 vs. post-Tr: 0.46 ± 0.03 mmol/kg dry wt). The decreased pyruvate availability during exercise post-Tr may be due to a decreased muscle glycogenolytic rate (pre-Tr: 13.22 ± 1.01 vs. post-Tr: 7.36 ± 1.26 mmol·min−1·kg dry wt−1). Decreased glycogenolysis was likely mediated, in part, by posttransformational regulation of Phos, as evidenced by smaller net increases in calculated muscle free ADP (pre-Tr: 111 ± 16 vs. post-Tr: 84 ± 10 μmol/kg dry wt) and Pi (pre-Tr: 57.1 ± 7.9 vs. post-Tr: 28.6 ± 5.6 mmol/kg dry wt). We have demonstrated for the first time that several signals act to coordinately regulate Phos and PDH, and thus carbohydrate metabolism, in human skeletal muscle after 7 wk of endurance training.


2008 ◽  
Vol 295 (6) ◽  
pp. R1991-R1998 ◽  
Author(s):  
David Bishop ◽  
Johann Edge ◽  
Claire Thomas ◽  
Jacques Mercier

The purpose of this study was to investigate the effects of high-intensity interval training (3 days/wk for 5 wk), provoking large changes in muscle lactate and pH, on changes in intracellular buffer capacity (βmin vitro), monocarboxylate transporters (MCTs), and the decrease in muscle lactate and hydrogen ions (H+) after exercise in women. Before and after training, biopsies of the vastus lateralis were obtained at rest and immediately after and 60 s after 45 s of exercise at 190% of maximal O2 uptake. Muscle samples were analyzed for ATP, phosphocreatine (PCr), lactate, and H+; MCT1 and MCT4 relative abundance and βmin vitro were also determined in resting muscle only. Training provoked a large decrease in postexercise muscle pH (pH 6.81). After training, there was a significant decrease in βmin vitro (−11%) and no significant change in relative abundance of MCT1 (96 ± 12%) or MCT4 (120 ± 21%). During the 60-s recovery after exercise, training was associated with no change in the decrease in muscle lactate, a significantly smaller decrease in muscle H+, and increased PCr resynthesis. These results suggest that increases in βmin vitro and MCT relative abundance are not linked to the degree of muscle lactate and H+ accumulation during training. Furthermore, training that is very intense may actually lead to decreases in βmin vitro. The smaller postexercise decrease in muscle H+ after training is a further novel finding and suggests that training that results in a decrease in H+ accumulation and an increase in PCr resynthesis can actually reduce the decrease in muscle H+ during the recovery from supramaximal exercise.


2017 ◽  
Vol 12 (7) ◽  
pp. 964-968 ◽  
Author(s):  
Bent R. Rønnestad ◽  
Gunnar Slettaløkken Falch ◽  
Stian Ellefsen

Postactivation-potentiation exercise with added whole-body vibration (WBV) has been suggested as a potential way to acutely improve sprint performance. In cycling, there are many competitions and situations where sprinting abilities are important.Purpose:To investigate the effect of adding WBV to warm-up procedures on subsequent cycle sprint performance.Methods:Eleven well-trained cyclists participated in the study. All cyclists performed a familiarization session before 2 separate test sessions in randomized order. Each session included a standardized warm-up followed by 1 of the following preconditioning exercises: 30 s of half-squats without WBV or 30 s of half-squats with WBV at 40 Hz. A 15-s Wingate sprint was performed 1 min after the preconditioning exercise.Results:Performing preconditioning exercise with WBV at 40 Hz resulted in superior peak power output compared with preconditioning exercise without WBV (1413 ± 257 W vs 1353 ± 213 W, P = .04) and a tendency toward superior mean power output during a 15-second all-out sprint (850 ± 119 W vs 828 ± 101 W, P = .08). Effect sizes showed a moderate practical effect of WBV vs no WBV on both peak and mean power output.Conclusions:Preconditioning exercise performed with WBV at 40 Hz seems to have a positive effect on cycling sprint performance in young well-trained cyclists. This suggests that athletes can incorporate body-loaded squats with WBV in preparations to specific sprint training to improve the quality of the sprint training and also to improve sprint performance in relevant competitions.


1993 ◽  
Vol 75 (2) ◽  
pp. 712-719 ◽  
Author(s):  
G. C. Gaitanos ◽  
C. Williams ◽  
L. H. Boobis ◽  
S. Brooks

Eight male subjects volunteered to take part in this study. The exercise protocol consisted of ten 6-s maximal sprints with 30 s of recovery between each sprint on a cycle ergometer. Needle biopsy samples were taken from the vastus lateralis muscle before and after the first sprint and 10 s before and immediately after the tenth sprint. The energy required to sustain the high mean power output (MPO) that was generated over the first 6-s sprint (870.0 +/- 159.2 W) was provided by an equal contribution from phosphocreatine (PCr) degradation and anaerobic glycolysis. Indeed, within the first 6-s bout of maximal exercise PCr concentration had fallen by 57% and muscle lactate concentration had increased to 28.6 mmol/kg dry wt, confirming significant glycolytic activity. However, in the tenth sprint there was no change in muscle lactate concentration even though MPO was reduced only to 73% of that generated in the first sprint. This reduced glycogenolysis occurred despite the high plasma epinephrine concentration of 5.1 +/- 1.5 nmol/l after sprint 9. In face of a considerable reduction in the contribution of anaerobic glycogenolysis to ATP production, it was suggested that, during the last sprint, power output was supported by energy that was mainly derived from PCr degradation and an increased aerobic metabolism.


2021 ◽  
Vol 11 (18) ◽  
pp. 8329
Author(s):  
Michal Krzysztofik ◽  
Rafal Kalinowski ◽  
Aleksandra Filip-Stachnik ◽  
Michal Wilk ◽  
Adam Zajac

Post-activation performance enhancement remains a topic of debate in sport science. The purpose of this study was to examine the effects of lower-body plyometric conditioning activity (CA) with a self-selected intra-complex rest interval on upper and lower-body volleyball specific performance. Eleven resistance-trained female volleyball players participated in the study (age: 20 ± 2 years; body mass: 67.8 ± 4.4 kg; height: 178 ± 6 cm; half back squat one-repetition maximum: 78.6 ± 10.2 kg; experience in resistance training: 5.5 ± 2.1 years and in volleyball training: 10 ± 2.3 years). Each participant performed a plyometric CA followed by two different sport-specific tests: an attack jump and a standing spike attack. The changes in jump height (JH), relative mean power output (MP) and ball velocity (BV) were analyzed before and after the CA with self-selected rest intervals. The applied plyometric CA with self-selected intra-complex rest intervals led to an insignificant decline in JH (p = 0.594; effect size [ES]: −0.27) and MP (p = 0.328; ES: −0.46) obtained during the attack jump as well as a significant decline in BV (p = 0.029; ES: −0.72) during the standing spike attack. This study showed that a plyometric CA with self-selected intra-complex rest intervals failed to elicit localized and non-localized PAPE effect in a group of sub-elite volleyball players.


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