Adaptations in skeletal muscle exercise metabolism to a sustained session of heavy intermittent exercise

2000 ◽  
Vol 278 (1) ◽  
pp. E118-E126 ◽  
Author(s):  
H. Green ◽  
R. Tupling ◽  
B. Roy ◽  
D. O'Toole ◽  
M. Burnett ◽  
...  
Keyword(s):  
Citrate Synthase ◽  
Intermittent Exercise ◽  
Vastus Lateralis ◽  
Maximal Oxygen Consumption ◽  
Training Session ◽  
Creatine Phosphate ◽  
Oxidative Potential ◽  
Similar Time ◽  
Muscle Lactate ◽  
Metabolic Adaptations

The purpose of this study was to investigate the hypothesis that a single, extended session of heavy exercise would be effective in inducing adaptations in energy metabolism during exercise in the absence of increases in oxidative potential. Ten healthy males [maximal aerobic power (V˙o 2 peak) = 43.4 ± 2.2 (SE) ml ⋅ kg−1 ⋅ min−1] participated in a 16-h training session involving cycling for 6 min each hour at ∼90% of maximal oxygen consumption. Measurements of metabolic changes were made on tissue extracted from the vastus lateralis during a two-stage standardized submaximal cycle protocol before (Pre) and 36–48 h after (Post) the training session. At Pre, creatine phosphate (PCr) declined ( P < 0.05) by 32% from 0 to 3 min and then remained stable until 20 min of exercise at 60%V˙o 2 peak before declining ( P < 0.05) by a further 35% during 20 min of exercise at 75%V˙o 2 peak. Muscle lactate (mmol/kg dry wt) progressively increased ( P < 0.05) from 4.59 ± 0.64 at 0 min to 17.8 ± 2.7 and 30.9 ± 5.3 at 3 and 40 min, respectively, whereas muscle glycogen (mmol glucosyl units/kg dry wt) declined ( P < 0.05) from a rest value of 360 ± 24 to 276 ± 31 and 178 ± 36 at similar time points. During exercise after the training session, PCr and glycogen were not as depressed ( P < 0.05), and increases in muscle lactate were blunted ( P < 0.05). All of these changes occurred in the absence of increases in oxidative potential as measured by the maximal activities of citrate synthase and malate dehydrogenase. These findings are consistent with other studies, namely, that muscle metabolic adaptations to regular exercise are an early adaptive event that occurs before increases in oxidative potential.

Increases in muscle MCT are associated with reductions in muscle lactate after a single exercise session in humans

2002 ◽  
Vol 282 (1) ◽  
pp. E154-E160 ◽  
Author(s):  
H. Green ◽  
A. Halestrap ◽  
C. Mockett ◽  
D. O'Toole ◽  
S. Grant ◽  
...  
Keyword(s):  
Vastus Lateralis ◽  
Training Session ◽  
Exercise Session ◽  
Vastus Lateralis Muscle ◽  
Single Session ◽  
Cycle Exercise ◽  
Muscle Lactate ◽  
Metabolic Adaptations ◽  
Exercise Muscle ◽  
Lactate Levels

To investigate the effects of a single session of prolonged cycle exercise [60% peak O2 uptake (V˙o 2 peak) for 5–6 h] on metabolic adaptations in working vastus lateralis muscle, nine untrained males (peak O2 uptake = 47.2 ± 1.1 ml · kg−1 · min−1, means ± SE) were examined before (Pre) and at 2 (Post-2), 4 (Post-4), and 6 (Post-6) days after the training session. On the basis of 15 min of cycle exercise at 59% V˙o 2 peak, it was found that training reduced ( P < 0.05) exercise muscle lactate (mM) at Post-2 (6.65 ± 0.69), Post-4 (7.74 ± 0.63), and Post-6 (7.78 ± 1.2) compared with Pre (10.9 ± 1.3). No effect of training was observed on exercise ATP, phosphocreatine, and glycogen levels. After the single session of training, plasma volumes were elevated ( P < 0.05) at Post-2 (6.7 ± 1.7%), Post-4 (5.86 ± 1.9), and Post-6 (5.13 ± 2.5). The single exercise session also resulted in elevations ( P< 0.05) in the monocarboxylate transporters MCT1 and MCT4 throughout the 6 days after exercise. Although epinephrine and norepinephrine both increased with exercise, only norepinephrine was reduced ( P < 0.05) with training and only at Post-4. These results indicate that regulation of cellular lactate levels occurs rapidly and independently of other metabolic adaptations. It is proposed that increases in MCT and plasma volume are at least partly involved in the lower muscle lactate content observed after the training session by increasing lactate membrane transport and removal, respectively.

Contractile and biochemical properties of diaphragm: effects of exercise training and fatigue

1986 ◽  
Vol 60 (5) ◽  
pp. 1752-1758 ◽  
Author(s):  
J. M. Metzger ◽  
R. H. Fitts
Keyword(s):  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Exercise Program ◽  
Creatine Phosphate ◽  
Biochemical Properties ◽  
Fatigue Properties ◽  
Marker Enzyme ◽  
Mitochondrial Marker ◽  
Muscle Lactate ◽  
Rate Limiting

The effect of high-intensity trained (6 X 4.5 min at 40 m/min, 15% grade, 2.5-min rest between bouts, 5 days/wk, for 6 wk) on contractile, biochemical, and fatigue properties of the rat diaphragm were examined. The exercise program produced significant elevations in the mitochondrial marker enzyme citrate synthase (mumol X g-1 X min-1) in the soleus (SOL) (27.2 +/- 1.5 vs. 46.7 +/- 2.4; mean +/- SE), deep vastus lateralis (DVL) (40.8 +/- 2.6 vs. 58.3 +/- 2.8), and superficial vastus lateralis (SVL) (8.5 +/- 0.6 vs. 11.4 +/- 0.7). No significant differences were observed in the crural (CRU) (45.9 +/- 2.0 vs. 44.0 +/- 2.3) or ventral costal (VEN) (41.5 +/- 2.0 vs. 45.8 +/- 2.6) diaphragmatic regions. Phosphofructokinase, the rate-limiting enzyme of glycolysis, significantly increased in the SOL (19.0 +/- 0.8 vs. 23.3 +/- 1.3 mumol X g-1 X min-1) and DVL (69.3 +/- 6.0 vs. 86.6 +/- 5.0), but no alterations were seen in the SVL (98.6 +/- 5.7 vs. 106.1 +/- 9.0), CRU (54.4 +/- 2.8 vs. 53.8 +/- 1.5), or VEN (44.7 +/- 2.4 vs. 46.4 +/- 1.4) posttraining. Diaphragm contractile properties, with the exception of an increased rate of fall in twitch tension, remained unchanged after training. Glycogen values were significantly higher in trained diaphragms at rest (6.54 +/- 0.39 vs. 4.86 +/- 0.41 mg/g) and during 1, 5, and 10 min of fatiguing stimulation. During fatigue no differences were observed in force, rate of rise in force, rate of fall in force, muscle lactate, ATP, or creatine phosphate in trained vs. control.(ABSTRACT TRUNCATED AT 250 WORDS)

Progressive effect of endurance training on metabolic adaptations in working skeletal muscle

1996 ◽  
Vol 270 (2) ◽  
pp. E265-E272 ◽  
Author(s):  
S. M. Phillips ◽  
H. J. Green ◽  
M. A. Tarnopolsky ◽  
G. J. Heigenhauser ◽  
S. M. Grant
Keyword(s):  
Endurance Training ◽  
Acute Exercise ◽  
Vastus Lateralis ◽  
Lactate Concentration ◽  
Vastus Lateralis Muscle ◽  
O2 Consumption ◽  
Oxidative Potential ◽  
Mitochondrial Potential ◽  
Muscle Lactate ◽  
Metabolic Adaptations

We investigated the hypothesis that a program of prolonged endurance training, previously shown to decrease metabolic perturbations to acute exercise within 5 days of training, would result in greater metabolic adaptations after a longer training duration. Seven healthy male volunteers [O2 consumption = 3.52 +/- 0.20 (SE) l/min] engaged in a training program consisting of 2 h of cycle exercise at 59% of pretraining peak O2 consumption (VO2peak) 5-6 times/wk. Responses to a 90-min submaximal exercise challenge were assessed pretraining (PRE) and after 5 and 31 days of training. On the basis of biopsies obtained from the vastus lateralis muscle, it was found that, after 5 days of training, muscle lactate concentration, phosphocreatine (PCr) hydrolysis, and glycogen depletion were reduced vs. PRE (all P < 0.01). Further training (26 days) showed that, at 31 days, the reduction in PCr and the accumulation of muscle lactate was even less than at 5 days (P < 0.01). Muscle oxidative potential, estimated from the maximal activity of succinate dehydrogenase, was increased only after 31 days of training (+41%; P < 0.01). In addition, VO2peak was only increased (10%) by 31 days (P < 0.05). The results show that a period of short-term training results in many characteristic training adaptations but that these adaptations occurred before increases in mitochondrial potential. However, a further period of training resulted in further adaptations in muscle metabolism and muscle phosphorylation potential, which were linked to the increase in muscle mitochondrial capacity.

Early muscular and metabolic adaptations to prolonged exercise training in humans

1991 ◽  
Vol 70 (5) ◽  
pp. 2032-2038 ◽  
Author(s):  
H. J. Green ◽  
S. Jones ◽  
M. E. Ball-Burnett ◽  
D. Smith ◽  
J. Livesey ◽  
...  
Keyword(s):  
Citrate Synthase ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Creatine Phosphate ◽  
Area Ratio ◽  
Vastus Lateralis Muscle ◽  
Metabolic Potential ◽  
Oxidative Potential ◽  
Fiber Area ◽  
Glycerophosphate Dehydrogenase

A short-term training program involving 2 h of daily exercise at 59% of peak O2 uptake (VO2max) repeated for 10-12 consecutive days was employed to determine the significance of adaptations in energy metabolic potential on alterations in energy metabolism and substrate utilization in working muscle. The initial VO2max determined before training on the eight male subjects was 53.0 +/- 2.0 (SE) ml.kg-1.min-1. Analysis of samples obtained by needle biopsy from the vastus lateralis muscle before exercise (0 min) and at 15, 60, and 99 min of exercise indicated that on the average training resulted (P less than 0.05) in a 6.5% higher concentration of creatine phosphate, a 9.9% lower concentration of creatine, and a 39% lower concentration of lactate. Training had no effect on ATP concentration. These adaptations were also accompanied by a reduction in the utilization in glycogen such that by the end of exercise glycogen concentration was 47.1% higher in the trained muscle. Analysis of the maximal activities of representative enzymes of different metabolic pathways and segments indicated no change in potential in the citric acid cycle (succinate dehydrogenase, citrate synthase), beta-oxidation (3-hydroxyacyl CoA dehydrogenase), glucose phosphorylation (hexokinase), or potential for glycogenolysis (phosphorylase) and glycolysis (pyruvate kinase, phosphofructokinase, alpha-glycerophosphate dehydrogenase, lactate dehydrogenase). With the exception of increases in the capillary-to-fiber area ratio in type IIa fibers, no change was found in any fiber type (types I, IIa, and IIb) for area, number of capillaries, capillary-to-fiber area ratio, or oxidative potential with training.(ABSTRACT TRUNCATED AT 250 WORDS)

Six sessions of sprint interval training increases muscle oxidative potential and cycle endurance capacity in humans

2005 ◽  
Vol 98 (6) ◽  
pp. 1985-1990 ◽  
Author(s):  
Kirsten A. Burgomaster ◽  
Scott C. Hughes ◽  
George J. F. Heigenhauser ◽  
Suzanne N. Bradwell ◽  
Martin J. Gibala
Keyword(s):  
Citrate Synthase ◽  
Training Session ◽  
Interval Training ◽  
Maximal Activity ◽  
Work Capacity ◽  
Control Group ◽  
Endurance Capacity ◽  
Sprint Interval Training ◽  
Oxidative Potential ◽  
Cycle Endurance

Parra et al. ( Acta Physiol. Scand 169: 157–165, 2000) showed that 2 wk of daily sprint interval training (SIT) increased citrate synthase (CS) maximal activity but did not change “anaerobic” work capacity, possibly because of chronic fatigue induced by daily training. The effect of fewer SIT sessions on muscle oxidative potential is unknown, and aside from changes in peak oxygen uptake (V̇o2 peak), no study has examined the effect of SIT on “aerobic” exercise capacity. We tested the hypothesis that six sessions of SIT, performed over 2 wk with 1–2 days rest between sessions to promote recovery, would increase CS maximal activity and endurance capacity during cycling at ∼80% V̇o2 peak. Eight recreationally active subjects [age = 22 ± 1 yr; V̇o2 peak = 45 ± 3 ml·kg−1·min−1 (mean ± SE)] were studied before and 3 days after SIT. Each training session consisted of four to seven “all-out” 30-s Wingate tests with 4 min of recovery. After SIT, CS maximal activity increased by 38% (5.5 ± 1.0 vs. 4.0 ± 0.7 mmol·kg protein−1·h−1) and resting muscle glycogen content increased by 26% (614 ± 39 vs. 489 ± 57 mmol/kg dry wt) (both P < 0.05). Most strikingly, cycle endurance capacity increased by 100% after SIT (51 ± 11 vs. 26 ± 5 min; P < 0.05), despite no change in V̇o2 peak. The coefficient of variation for the cycle test was 12.0%, and a control group ( n = 8) showed no change in performance when tested ∼2 wk apart without SIT. We conclude that short sprint interval training (∼15 min of intense exercise over 2 wk) increased muscle oxidative potential and doubled endurance capacity during intense aerobic cycling in recreationally active individuals.

Altitude acclimatization and energy metabolic adaptations in skeletal muscle during exercise

1992 ◽  
Vol 73 (6) ◽  
pp. 2701-2708 ◽  
Author(s):  
H. J. Green ◽  
J. R. Sutton ◽  
E. E. Wolfel ◽  
J. T. Reeves ◽  
G. E. Butterfield ◽  
...  
Keyword(s):  
Prolonged Exercise ◽  
Vastus Lateralis ◽  
Acute Hypoxia ◽  
Lactate Concentration ◽  
Absolute Intensity ◽  
Muscle Lactate ◽  
Arterial Lactate ◽  
Metabolic Adaptations ◽  
Exercise Challenge ◽  
Male Subjects

To determine whether the working muscle is able to sustain ATP homeostasis during a hypoxic insult and the mechanisms associated with energy metabolic adaptations during the acclimatization process, seven male subjects [23 +/- 2 (SE) yr, 72.2 +/- 1.6 kg] were given a prolonged exercise challenge (45 min) at sea level (SL), within 4 h after ascent to an altitude of 4,300 m (acute hypoxia, AH), and after 3 wk of sustained residence at 4,300 m (chronic hypoxia, CH). The prolonged cycle test conducted at the same absolute intensity and representing 51 +/- 1% of SL maximal aerobic power (VO2 max) and between 64 +/- 2 (AH) and 66 +/- 1% (CH) at altitude was performed without a reduction in ATP concentration in the working vastus lateralis regardless of condition. Compared with rest, exercise performed during AH resulted in a greater increase (P < 0.05) in muscle lactate concentration (5.11 +/- 0.68 to 22.3 +/- 6.1 mmol/kg dry wt) than exercise performed either at SL (5.88 +/- 0.85 to 11.5 +/- 3.1) or CH (5.99 +/- 0.88 to 12.4 +/- 2.1). These differences in lactate concentration have been shown to reflect differences in arterial lactate concentration and glycolysis (Brooks et al. J. Appl. Physiol. 71: 333–341, 1991). The reduction in glycolysis at least between AH and CH appears to be accompanied by a tighter metabolic control. During CH, free ADP was lower and the ATP-to-free ADP ratio was increased (P < 0.05) compared with AH.(ABSTRACT TRUNCATED AT 250 WORDS)

Initial aerobic power does not alter muscle metabolic adaptations to short-term training

1999 ◽  
Vol 277 (1) ◽  
pp. E39-E48 ◽  
Author(s):  
H. Green ◽  
S. Grant ◽  
E. Bombardier ◽  
D. Ranney
Keyword(s):  
Time Course ◽  
Citrate Synthase ◽  
Aerobic Power ◽  
Vastus Lateralis ◽  
Maximal Activity ◽  
Short Term ◽  
Mitochondrial Potential ◽  
Metabolic Adaptations ◽  
Enzymatic Changes ◽  
Male Subjects

To investigate the hypothesis that training-induced increases in muscle mitochondrial potential are not obligatory to metabolic adaptations observed during submaximal exercise, regardless of peak aerobic power (V˙o 2 peak) of the subjects, a short-term training study was utilized. Two groups of untrained male subjects ( n = 7/group), one with a high (HI) and the other with a low (LO)V˙o 2 peak(means ± SE; 51.4 ± 0.90 vs. 41.0 ± 1.3 ml ⋅ kg−1 ⋅ min−1; P< 0.05), cycled for 2 h/day at 66–69% ofV˙o 2 peak for 6 days. Muscle tissue was extracted from vastus lateralis at 0, 3, and 30 min of standardized cycle exercise before training (0 days) and after 3 and 6 days of training and analyzed for metabolic and enzymatic changes. During exercise after 3 days of training in the combined HI + LO group, higher ( P < 0.05) concentrations (mmol/kg dry wt) of phosphocreatine (40.5 ± 3.4 vs. 52.2 ± 4.2) and lower ( P < 0.05) concentrations of Pi (61.5 ± 4.4 vs. 53.3 ± 4.4), inosine monophosphate (0.520 ± 0.19 vs. 0.151 ± 0.05), and lactate (37.9 ± 5.5 vs. 22.8 ± 4.8) were observed. These changes were also accompanied by reduced levels of calculated free ADP, AMP, and Pi. All adaptations were fully expressed by 3 min of exercise and by 3 days of training and were independent of initialV˙o 2 peak levels. Moreover, maximal activity of citrate synthase, a measure of mitochondrial capacity, was only increased with 6 days of training (5.71 ± 0.29 vs. 7.18 ± 0.37 mol ⋅ kg protein−1 ⋅ h−1; P < 0.05). These results demonstrate that metabolic adaptations to prolonged exercise occur within the first 3 days of training and during the non-steady-state period. Moreover, neither time course nor magnitude of metabolic adaptations appears to depend on increases in mitochondrial potential or on initial aerobic power.

Short-term training increases human muscle MCT1 and femoral venous lactate in relation to muscle lactate

1998 ◽  
Vol 274 (1) ◽  
pp. E102-E107 ◽  
Author(s):  
A. Bonen ◽  
K. J. A. McCullagh ◽  
C. T. Putman ◽  
E. Hultman ◽  
N. L. Jones ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Vastus Lateralis ◽  
Venous Blood ◽  
Maximal Oxygen Consumption ◽  
Bicycle Ergometer ◽  
Monocarboxylate Transporter ◽  
Short Term ◽  
Bicycle Ergometry ◽  
Muscle Lactate ◽  
Monocarboxylate Transporter 1

We examined the effects of increasing a known lactate transporter protein, monocarboxylate transporter 1 (MCT1), on lactate extrusion from human skeletal muscle during exercise. Before and after short-term bicycle ergometry training [2 h/day, 7 days at 65% maximal oxygen consumption (V˙o 2 max)], subjects ( n = 7) completed a continuous bicycle ergometer ride at 30%V˙o 2 max (15 min), 60%V˙o 2 max (15 min), and 75% V˙o 2 max (15 min). Muscle biopsy samples (vastus lateralis) and arterial and femoral venous blood samples were obtained before exercise and at the end of each workload. After 7 days of training the MCT1 content in muscle was increased (+18%; P < 0.05). The concentrations of both muscle lactate and femoral venous lactate were reduced during exercise ( P < 0.05) that was performed after training. High correlations were observed between muscle lactate and venous lactate before training ( r = 0.92, P < 0.05) and after training ( r = 0.85, P < 0.05), but the slopes of the regression lines between these variables differed markedly. Before training, the slope was 0.12 ± 0.01 mM lactate ⋅ mmol lactate−1 ⋅ kg muscle dry wt−1, and this was increased by 33% after training to 0.18 ± 0.02 mM lactate ⋅ mmol lactate−1 ⋅ kg muscle dry wt−1. This indicated that after training the femoral venous lactate concentrations were increased for a given amount of muscle lactate. These results suggest that lactate extrusion from exercising muscles is increased after training, and this may be associated with the increase in skeletal muscle MCT1.

Creatine supplementation increases muscle total creatine but not maximal intermittent exercise performance

1999 ◽  
Vol 87 (6) ◽  
pp. 2244-2252 ◽  
Author(s):  
Michael J. McKenna ◽  
Judith Morton ◽  
Steve E. Selig ◽  
Rodney J. Snow
Keyword(s):  
Time Course ◽  
Intermittent Exercise ◽  
Vastus Lateralis ◽  
Creatine Supplementation ◽  
Creatine Phosphate ◽  
Dry Mass ◽  
Cycle Ergometer ◽  
Initial Increase ◽  
Main Effect ◽  
Total Creatine

This study investigated creatine supplementation (CrS) effects on muscle total creatine (TCr), creatine phosphate (CrP), and intermittent sprinting performance by using a design incorporating the time course of the initial increase and subsequent washout period of muscle TCr. Two groups of seven volunteers ingested either creatine [Cr; 6 × (5 g Cr-H2O + 5 g dextrose)/day)] or a placebo (6 × 5 g dextrose/day) over 5 days. Five 10-s maximal cycle ergometer sprints with rest intervals of 180, 50, 20, and 20 s and a resting vastus lateralis biopsy were conducted before and 0, 2, and 4 wk after placebo or CrS. Resting muscle TCr, CrP, and Cr were unchanged after the placebo but were increased ( P < 0.05) at 0 [by 22.9 ± 4.2, 8.9 ± 1.9, and 14.0 ± 3.3 (SE) mmol/kg dry mass, respectively] and 2 but not 4 wk after CrS. An apparent placebo main effect of increased peak power and cumulative work was found after placebo and CrS, but no treatment (CrS) main effect was found on either variable. Thus, despite the rise and washout of muscle TCr and CrP, maximal intermittent sprinting performance was unchanged by CrS.

Decreased glucose turnover after short-term training is unaccompanied by changes in muscle oxidative potential

1995 ◽  
Vol 269 (2) ◽  
pp. E222-E230 ◽  
Author(s):  
S. M. Phillips ◽  
H. J. Green ◽  
M. A. Tarnopolsky ◽  
S. M. Grant
Keyword(s):  
Blood Glucose ◽  
Citrate Synthase ◽  
Blood Glucose Concentration ◽  
Vastus Lateralis ◽  
Glucose Turnover ◽  
Vastus Lateralis Muscle ◽  
Metabolic Clearance ◽  
Glycogen Depletion ◽  
Oxidative Potential ◽  
Mitochondrial Potential

This study investigated the hypothesis that training-induced reductions in exercise blood glucose utilization can occur independently of increases in muscle mitochondrial potential. To induce a training adaptation, eight active participants (23 +/- 1 yr, 80.6 +/- 3.7 kg, mean +/- SE) with a maximal oxygen consumption (VO2max) of 45.5 +/- 2.4 ml.kg-1.min-1, cycled at 59% VO2max for 2 h per day for 10 consecutive days. Measurements of blood glucose appearance (Ra) and disappearance (Rd), using a primed continuous infusion of [6,6-2H2]glucose, were made during 90 min of cycle exercise (59% VO2max) performance before and after training. Training resulted in a 25% decrease (P < 0.01) in mean glucose Ra during exercise (43.0 +/- 3.7 to 34.4 +/- 2.8 mumol.kg-1.min-1). Since blood glucose concentration was not different between training conditions, glucose metabolic clearance rate was also depressed (P < 0.05). Exercise-induced glycogen depletion in vastus lateralis muscle was reduced (P < 0.05) with training. Calculation of carbohydrate and fat oxidation based on the respiratory exchange ratio supported a shift toward greater preference for fat. Because training did not elicit changes in the maximal activities of citrate synthase and malate dehydrogenase, two enzymes of the citric acid cycle, it would appear that increases in mitochondrial potential are not necessary for the adaptations that occurred.

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