Metabolic adaptations to short-term training are expressed early in submaximal exercise

1995 ◽  
Vol 73 (4) ◽  
pp. 474-482 ◽  
Author(s):  
H. J. Green ◽  
M. Ball-Burnett ◽  
G. Jamieson ◽  
J. Cadefau ◽  
R. Cussó
Keyword(s):  
Steady State ◽  
Metabolic Control ◽  
Vastus Lateralis ◽  
Lactate Concentration ◽  
Muscle Metabolism ◽  
Dry Weight ◽  
Submaximal Exercise ◽  
Short Term ◽  
Oxidative Potential ◽  
Metabolic Adaptations

In previous studies we have been able to demonstrate tighter metabolic control of muscle metabolism during prolonged steady-state exercise 5 to 6 days after the initiation of training and well before changes in oxidative potential. To examine whether the metabolic adaptations are manifested during the non-steady-state adjustment to submaximal exercise, 11 male subjects ([Formula: see text] peak, 45 ± 2.4 mL∙kg−1∙min−1, [Formula: see text]) performed 98 min of cycle exercise at 67% of [Formula: see text] peak prior to and following 3 to 4 days of training for 2 h per day. Analysis of lactate concentration (mmol/kg dry weight) in samples rapidly extracted from vastus lateralis indicated reductions (p < 0.05) of 44% at 3 min (42.1 ± 7.1 vs. 23.6 ± 7.7), 29% at 15 min (35.4 ± 6.4 vs. 25.0 ± 6.0), and 32% at 98 min (22.9 ± 6.9 vs. 15.6 ± 3.2) with training. Training also resulted in higher phosphocreatine and lower creatine and Pi values that were not specific to any exercise time point. In addition, [Formula: see text] was not altered either during the non-steady state or during the steady-state phases of exercise. These results suggest that at least part of the tightening of the metabolic control and the apparent reduction in glycogenolysis and glycolysis in response to short-term training occurs during the adjustment phase to steady-state exercise.Key words: training, metabolic control, nonsteady state.

Adaptations in muscle metabolism to prolonged voluntary exercise and training

1995 ◽  
Vol 78 (1) ◽  
pp. 138-145 ◽  
Author(s):  
H. J. Green ◽  
S. Jones ◽  
M. Ball-Burnett ◽  
B. Farrance ◽  
D. Ranney
Keyword(s):  
Metabolic Response ◽  
Vastus Lateralis ◽  
Lactate Concentration ◽  
Succinic Dehydrogenase ◽  
Voluntary Exercise ◽  
Glycogen Depletion ◽  
O2 Uptake ◽  
Short Term ◽  
Oxidative Potential ◽  
Metabolic Adaptations

In previous research we established using a short-term (5–7 days) training model that increases in muscle oxidative potential are not a prerequisite for the characteristic energy metabolic adaptations (lower lactate, glycogen depletion, and phosphocreatine hydrolysis) observed during prolonged exercise. To investigate whether increased muscle aerobic potential further potentiates the metabolic adaptive response, seven healthy male volunteers [maximal O2 uptake (VO2max) = 45.1 +/- 1.1 (SE) ml.kg-1.min-1] engaged in an 8-wk training program consisting of 2 h of cycle exercise at 62% of pretraining VO2max 5–6 times/wk. Analysis of tissue samples obtained from the vastus lateralis after 60 min of exercise revealed that by 4 wk of training muscle lactate concentration, phosphocreatine hydrolysis, and glycogen depletion were depressed (all P < 0.05). Further training for 4 wk had no additional effect (P < 0.05). The ratio of fructose 6-phosphate to fructose 1,6-phosphate, an index of phosphofructokinase activity, was not altered with training. Muscle oxidative potential as estimated from the maximal activity of succinic dehydrogenase increased by 31% by 4 wk of training (P <0.05) before plateauing during the final 4 wk of training. The increase in VO2max of 15.6% (P < 0.05) noted with training was also primarily expressed during the initial 4 wk. O2 uptake during submaximal exercise was unchanged. Because the metabolic response was similar in magnitude to that previously observed with short-term training, we conclude that, at least for the conditions of this study, the development of increased muscle aerobic potential is of minimal consequence on the magnitude of the energy metabolic adaptations examined.

scholarly journals High-resistance training and muscle metabolism during prolonged exercise

1999 ◽  
Vol 276 (3) ◽  
pp. E489-E496 ◽  
Author(s):  
C. Goreham ◽  
H. J. Green ◽  
M. Ball-Burnett ◽  
D. Ranney
Keyword(s):  
Resistance Training ◽  
High Resistance ◽  
Metabolic Response ◽  
Muscle Metabolism ◽  
Submaximal Exercise ◽  
Oxidative Potential ◽  
Cross Sectional ◽  
Metabolic Adaptations ◽  
Before And After ◽  
Rate Of Oxygen Consumption

To investigate the hypothesis that changes in muscle submaximal exercise metabolism would occur as a result of fiber hypertrophy, induced by high-resistance training (HRT), active but untrained males (age 20 ± 0.7 yr; mean ± SE) performed lower-limb weight training 3 days/wk for 12 wk using three sets of 6–8 repetitions maximal (RM)/day. Muscle metabolism was examined at different stages of training (4, 7, and 12 wk) using a two-stage continuous cycle test performed at the same absolute power output and duration (56.4 ± 2.9 min) and representing 57 and 72% of pretraining peak aerobic power (V˙o 2 peak). Compared with pretraining, at the end of exercise, HRT resulted in a higher ( P < 0.05) phosphocreatine (PCr; 27.4 ± 6.7 vs. 38.0 ± 1.9 mmol/kg dry wt), a lower lactate (38.9 ± 8.5 vs. 24.4 ± 6.1 mmol/kg dry wt), and a higher ( P < 0.05) glycogen content (132 ± 11 vs. 181 ± 7.5 mmol glucosyl units/kg dry wt). The percent change from rest before and after training was 63 and 50% for PCr, 676 and 410% for lactate, and 60 and 43% for glycogen, respectively. These adaptations, which were observed only at 72%V˙o 2 peak, occurred by 4 wk of training in the case of PCr and glycogen and before any changes in fiber cross-sectional area, capillarization, or oxidative potential. Fiber hypertrophy, observed at 7 and 12 wk of training, failed to potentiate the metabolic response. No effect of HRT was found onV˙o 2 peak with training (41.2 ± 2.9 vs. 41.0 ± 2.1 ml ⋅ kg−1 ⋅ min−1) or on the steady-state, submaximal exercise rate of oxygen consumption. It is concluded that the HRT results in muscle metabolic adaptations that occur independently of fiber hypertrophy.

7 DO METABOLIC ADAPTATIONS TO SUBMAXIMAL EXERCISE FOLLOWING SHORT TERM TRAINING OCCUR DURING THE NON-STEADY STATE PHASE?

1993 ◽  
Vol 25 (Supplement) ◽  
pp. S2
Author(s):  
H. J. Green ◽  
J. Cadefau ◽  
R. Cuss?? ◽  
M. Ball-Barnett ◽  
S. Grant ◽  
...  
Keyword(s):  
Steady State ◽  
Submaximal Exercise ◽  
Short Term ◽  
Metabolic Adaptations

Time-dependent effects of short-term training on muscle metabolism during the early phase of exercise

2009 ◽  
Vol 297 (5) ◽  
pp. R1383-R1391 ◽  
Author(s):  
H. J. Green ◽  
E. Bombardier ◽  
M. E. Burnett ◽  
I. C. Smith ◽  
S. M. Tupling ◽  
...  
Keyword(s):  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Succinic Dehydrogenase ◽  
Muscle Metabolism ◽  
Short Term ◽  
Oxidative Potential ◽  
Tissue Samples ◽  
Nonsteady State ◽  
Pyruvate Ratio

In this study, we investigated the hypothesis that the metabolic adaptations observed during steady-state exercise soon after the onset of training would be displayed during the nonsteady period of moderate exercise and would occur in the absence of increases in peak aerobic power (V̇o2peak) and in muscle oxidative potential. Nine untrained males [age = 20.8 ± 0.70 (SE) yr] performed a cycle task at 62% V̇o2peak before (Pre-T) and after (Post-T) training for 2 h/day for 5 days at task intensity. Tissue samples extracted from the vastus lateralis at 0 min (before exercise) and at 10, 60, and 180 s of exercise, indicated that at Pre-T, reductions ( P < 0.05) in phosphocreatine and increases ( P < 0.05) in creatine, inorganic phosphate, calculated free ADP, and free AMP occurred at 60 and 180 s but not at 10 s. At Post-T, the concentrations of all metabolites were blunted ( P < 0.05) at 60 s. Training also reduced ( P < 0.05) the increase in lactate and the lactate-to-pyruvate ratio observed during exercise at Pre-T. These adaptations occurred in the absence of change in V̇o2peak (47.8 ± 1.7 vs. 49.2 ± 1.7 ml·kg−1·min−1) and in the activities (mol·kg protein−1·h−1) of succinic dehydrogenase (3.48 ± 0.21 vs. 3.77 ± 0.35) and citrate synthase (7.48 ± 0.61 vs. 8.52 ± 0.65) but not cytochrome oxidase (70.8 ± 5.1 vs. 79.6 ± 6.6 U/g protein; P < 0.05). It is concluded that the tighter metabolic control observed following short-term training is initially expressed during the nonsteady state, probably as a result of increases in oxidative phosphorylation that is not dependent on changes in V̇o2peak while the role of oxidative potential remains uncertain.

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.

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.

Can increases in capillarization explain the early adaptations in metabolic regulation in human muscle to short-term training?

2012 ◽  
Vol 90 (5) ◽  
pp. 557-566 ◽  
Author(s):  
Howard J. Green ◽  
Margaret Burnett ◽  
Helen Kollias ◽  
Jing Ouyang ◽  
Ian Smith ◽  
...  
Keyword(s):  
Fibre Type ◽  
Metabolic Regulation ◽  
Vastus Lateralis ◽  
Succinic Dehydrogenase ◽  
Capillary Density ◽  
Peak Oxygen Consumption ◽  
Short Term ◽  
Oxidative Potential ◽  
Fibre Area ◽  
Fibre Type Distribution

To investigate the hypothesis that increases in fibre capillary density would precede increases in oxidative potential following training onset, tissue was extracted from the vastus lateralis prior to (0 days) and following 3 and 6 consecutive days of submaximal cycle exercise (2 h·day–1). Participants were untrained males (age = 21.4 ± 0.58 years; peak oxygen consumption = 46.2 ± 1.6 mL·kg–1·min–1; mean ± standard error (SE)). Tissue was assessed for succinic dehydrogenase activity (SDH) by microphotometry and indices of capillarization based on histochemically assessed area and capillary counts (CC) in specific fibre types. Three days of training (n = 13) resulted in a generalized decrease (p < 0.05) in fibre area (–14.2% ± 3.0%; mean ± SE) and increase (p < 0.05) in CC/Area (20.4% ± 2.7%) and no change in either CC or SDH activity. Following 6 days of treatment (n = 6), increases (p < 0.05) in CC (18.2% ± 4.2%), CC/Area (28.9% ± 3.2%), and SDH activity (22.9% ± 6.0%) occurred that was not specific to major fibre type. No changes in either fibre area or fibre-type distribution were observed with additional training. We conclude that increases in angiogenic-based capillary density and oxidative potential occur coincidentally following training onset, while increases in capillary density, mediated by reductions in fibre area, represent an initial isolated response, the significance of which may be linked to the metabolic alterations that also result.

Sign in / Sign up

Export Citation Format

Share Document