Increased muscle oxidative potential following resistance training induced fibre hypertrophy in young men

2006 ◽  
Vol 31 (5) ◽  
pp. 495-501 ◽  
Author(s):  
Jason E. Tang ◽  
Joseph W. Hartman ◽  
Stuart M. Phillips
Keyword(s):  
Resistance Training ◽  
Muscle Fibre ◽  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Atp Synthesis ◽  
Acid Oxidation ◽  
Mitochondrial Enzymes ◽  
Oxidative Potential ◽  
Cross Sectional ◽  
Resistance Training Program

Some evidence suggests that resistance training may lower relative muscle mitochondrial content via “dilution” of the organelle in a larger muscle fibre. Such an adaptation would reduce fatigue resistance, as well as compromise oxidative ATP synthesis and the capacity for fatty-acid oxidation. We investigated the effect of resistance training on mitochondrial enzymes of the citric acid cycle (citrate synthase; CS) and β-oxidation (β-hydroxyacyl CoA dehydrogenase; β-HAD), as well as markers of the potential for glucose phosphorylation (hexokinase; HK) and glycolysis (phosphofructokinase; PFK). Twelve untrained men (21.9 ± 0.5 y; 1.79 ± 0.03 m; 83.2 ± 3.2 kg) participated in a 12 week progressive resistance-training program. Muscle biopsies were taken from the vastus lateralis before (PRE) and after (POST) training. Training increased mean muscle fibre cross-sectional area (p < 0.05) and the activities of CS (PRE = 4.53 ± 0.44 mol·kg protein–1·h–1; POST = 5.63 ± 0.40 mol·kg protein–1·h–1; p < 0.001) and β-HAD (PRE = 2.55 ± 0.28 mol·kg protein–1·h–1; POST = 3.11 ± 0.21 mol·kg protein–1·h–1; p < 0.05). The activity of HK increased 42% (p < 0.05), whereas the activity of PFK remained unchanged. We conclude that resistance training provides a stimulus for improving muscle oxidative potential, as reflected by the increased activities of CS and β-HAD following resistance training induced hypertrophy.

scholarly journals Downregulation in muscle Na+-K+-ATPase following a 21-day expedition to 6,194 m

2000 ◽  
Vol 88 (2) ◽  
pp. 634-640 ◽  
Author(s):  
Howard Green ◽  
Brian Roy ◽  
Susan Grant ◽  
Margaret Burnett ◽  
Russ Tupling ◽  
...  
Keyword(s):  
Citrate Synthase ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Succinic Dehydrogenase ◽  
Vastus Lateralis Muscle ◽  
Mitochondrial Enzymes ◽  
Succinic Dehydrogenase Activity ◽  
Oxidative Potential ◽  
Tissue Samples ◽  
Fiber Type Distribution

To investigate the hypothesis that acclimatization to altitude would result in a downregulation in muscle Na+-K+-ATPase pump concentration, tissue samples were obtained from the vastus lateralis muscle of six volunteers (5 males and 1 female), ranging in age from 24 to 35 yr, both before and within 3 days after a 21-day expedition to the summit of Mount Denali, Alaska (6,194 m). Na+-K+-ATPase, measured by the [3H]ouabain-binding technique, decreased by 13.8% [348 ± 12 vs. 300 ± 7.6 (SE) pmol/g wet wt; P< 0.05]. No changes were found in the maximal activities (mol ⋅ kg protein− 1 ⋅ h− 1) of the mitochondrial enzymes, succinic dehydrogenase (3.63 ± 0.20 vs. 3.25 ± 0.23), citrate synthase (4.76 ± 0.44 vs. 4.94 ± 0.44), and malate dehydrogenase (12.6 ± 1.8 vs. 12.7 ± 1.2). Similarly, the expedition had no effect on any of the histochemical properties examined, namely fiber-type distribution (types I, IIA, IIB, IC, IIC, IIAB), area, capillarization, and succinic dehydrogenase activity. Peak aerobic power (52.3 ± 2.1 vs. 50.6 ± 1.9 ml ⋅ kg− 1 ⋅ min− 1) and body mass (76.9 ± 3.7 vs. 75.5 ± 2.9 kg) were also unaffected. We concluded that acclimatization to altitude results in a downregulation in muscle Na+-K+-ATPase pump concentration, which occurs without changes in oxidative potential and other fiber-type histochemical properties.

scholarly journals Resistance Training does not Induce Uniform Adaptations to Quadriceps Muscles

2018 ◽  
Author(s):  
Gerald T. Mangine ◽  
Michael J. Redd ◽  
Adam M. Gonzalez ◽  
Jeremy R. Townsend ◽  
Adam J Wells ◽  
...  
Keyword(s):  
Resistance Training ◽  
High Intensity ◽  
Repeated Measures ◽  
Vastus Lateralis ◽  
Muscle Thickness ◽  
Rectus Femoris ◽  
Muscle Size ◽  
Fascicle Length ◽  
Cross Sectional ◽  
Resistance Training Program

AbstractResistance training may differentially affect morphological adaptations along the length of uni-articular and bi-articular muscles. The purpose of this study was to compare changes in muscle morphology along the length of the rectus femoris (RF) and vastus lateralis (VL) in response to resistance training. Following a 2-wk preparatory phase, 15 resistance-trained men (24.0 ± 3.0 y, 90.0 ± 13.8 kg, 174.9 ± 20.7 cm) completed pre-training (PRE) assessments of muscle thickness (MT), pennation angle (PA), cross-sectional area (CSA), and echo-intensity in the RF and VL at 30, 50, and 70% of each muscle’s length; fascicle length (FL) was estimated from respective measurements of MT and PA within each muscle and region. Participants then began a high intensity, low volume (4 × 3 − 5 repetitions, 3min rest) lower-body resistance training program, and repeated all PRE-assessments after 8 weeks (2 d · wk−1) of training (POST). Although three-way (muscle [RF, VL] × region [30, 50, 70%] × time [PRE, POST]) repeated measures analysis of variance did not reveal significant interactions for any assessment of morphology, significant simple (muscle × time) effects were observed for CSA (p = 0.002) and FL (p = 0.016). Specifically, average CSA changes favored the VL (2.96 ± 0.69 cm2, pp < 0.001) over the RF (0.59 ± 0.20 cm2, p = 0.011), while significant decreases in average FL were noted for the RF (–1.03 ± 0.30 cm, p = 0.004) but not the VL (–0.05 ± 0.36 cm, p = 0.901). No other significant differences were observed. The findings of this study demonstrate the occurrence of non-homogenous adaptations in RF and VL muscle size and architecture following 8 weeks of high-intensity resistance training in resistance-trained men. However, training does not appear to influence region-specific adaptations in either muscle.

Regulation of fiber size, oxidative potential, and capillarization in human muscle by resistance exercise

1999 ◽  
Vol 276 (2) ◽  
pp. R591-R596 ◽  
Author(s):  
H. Green ◽  
C. Goreham ◽  
J. Ouyang ◽  
M. Ball-Burnett ◽  
D. Ranney
Keyword(s):  
Fiber Type ◽  
Vastus Lateralis ◽  
Succinic Dehydrogenase ◽  
Quadriceps Muscle ◽  
Cellular Tissue ◽  
Cross Sectional Area ◽  
Fiber Types ◽  
Sectional Area ◽  
Oxidative Potential ◽  
Cross Sectional

To examine the hypothesis that increases in fiber cross-sectional area mediated by high-resistance training (HRT) would result in a decrease in fiber capillarization and oxidative potential, regardless of fiber type, we studied six untrained males (maximum oxygen consumption, 45.6 ± 2.3 ml ⋅ kg−1 ⋅ min−1; mean ± SE) participating in a 12-wk program designed to produce a progressive hypertrophy of the quadriceps muscle. The training sessions, which were conducted 3 times/wk, consisted of three sets of three exercises, each performed for 6–8 repetitions maximum (RM). Measurements of fiber-type distribution obtained from tissue extracted from the vastus lateralis at 0, 4, 7, and 12 wk indicated reductions ( P < 0.05) in type IIB fibers (15.1 ± 2.1% vs. 7.2 ± 1.3%) by 4 wk in the absence of changes in the other fiber types (types I, IIA, and IIAB). Training culminated in a 17% increase ( P < 0.05) in cross-sectional area by 12 wk with initial increases observed at 4 wk. The increase was independent of fiber type-specific changes. The number of capillaries in contact with each fiber type increased by 12 wk, whereas capillary contacts-to-fiber area ratios remained unchanged. In a defined cross-sectional field, HRT also increased the capillaries per fiber at 12 wk. Training failed to alter cellular oxidative potential, as measured by succinic dehydrogenase (SDH) activity, regardless of fiber type and training duration. It is concluded that modest hypertrophy induced by HRT does not compromise cellular tissue capillarization and oxidative potential regardless of fiber type.

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.

Rat diaphragm during postnatal development. I. Changes in distribution of muscle fibre type and in oxidative potential

1996 ◽  
Vol 8 (3) ◽  
pp. 391 ◽  
Author(s):  
MD Fratacci ◽  
M Levame ◽  
A Rauss ◽  
H Bousbaa ◽  
G Atlan
Keyword(s):  
Muscle Fibre ◽  
Fibre Type ◽  
Oxidative Capacity ◽  
Cross Sectional Area ◽  
Fibre Types ◽  
Type I ◽  
Sectional Area ◽  
Rat Diaphragm ◽  
Oxidative Potential ◽  
Cross Sectional

The changes occurring in the histochemical characteristics of the rat diaphragm during the postnatal period were examined. Fibre-type distribution, fibre oxidative capacity, i.e. succinate-dehydrogenase (SDH) activity, and cross-sectional area were compared in the costal (COS) and crural (CRU) regions, and across their abdominal and thoracic surfaces. The proportions of type I and IIb fibres in both COS and CRU increased with age, while the proportion of type IIa fibres progressively decreased. For COS, fibre distribution was homogeneous over the entire muscle and did not change after 4 weeks. For CRU, it was heterogeneous with a higher proportion of type I fibres on the thoracic surface as from the first week. All fibre types significantly increased in cross-sectional area between 1 and 8 weeks, with no significant differences in COS and CRU. Mean SDH activity did not differ between COS and CRU or across the muscles. Mean SDH activities-were low and identical in all fibre types at birth, and then increased, peaking at the 6th week in type I and IIa fibres. When total muscle fibre oxidative capacity was calculated from an index including fibre-type proportion, cross-sectional area and mean SDH activity, it was significantly higher at 1 than at 8 weeks after birth; this might have functional implications for the newborn.

scholarly journals Frequent Manipulation of Resistance Training Variables Promotes Myofibrillar Spacing Changes in Resistance-Trained Individuals

2021 ◽  
Vol 12 ◽  
Author(s):  
Carlton D. Fox ◽  
Paulo H. C. Mesquita ◽  
Joshua S. Godwin ◽  
Vitor Angleri ◽  
Felipe Damas ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Resistance Training ◽  
Relative Abundance ◽  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Volume Load ◽  
Protein Pool ◽  
Percent Area ◽  
Actin Protein ◽  
Training Protocols

We sought to determine if manipulating resistance training (RT) variables differentially altered the expression of select sarcoplasmic and myofibril proteins as well as myofibrillar spacing in myofibers. Resistance-trained men (n = 20; 26 ± 3 years old) trained for 8 weeks where a randomized leg performed either a standard (CON) or variable RT protocol (VAR: manipulation of load, volume, muscle action, and rest intervals at each RT session). A pre-training (PRE) vastus lateralis biopsy was obtained from a randomized single leg, and biopsies were obtained from both legs 96 h following the last training bout. The sarcoplasmic protein pool was assayed for proteins involved in energy metabolism, and the myofibril protein pool was assayed for relative myosin heavy chain (MHC) and actin protein abundances. Sections were also histologically analyzed to obtain myofibril spacing characteristics. VAR resulted in ~12% greater volume load (VL) compared to CON (p &lt; 0.001). The mean fiber cross-sectional area increased following both RT protocols [CON: 14.6% (775.5 μm2), p = 0.006; VAR: 13.9% (743.2 μm2), p = 0.01 vs. PRE for both], but without significant differences between protocols (p = 0.79). Neither RT protocol affected a majority of assayed proteins related to energy metabolism, but both training protocols increased hexokinase 2 protein levels and decreased a mitochondrial beta-oxidation marker (VLCAD protein; p &lt; 0.05). Citrate synthase activity levels increased with CON RT (p &lt; 0.05), but not VAR RT. The relative abundance of MHC (summed isoforms) decreased with both training protocols (p &lt; 0.05). However, the relative abundance of actin protein (summed isoforms) decreased with VAR only (13.5 and 9.0%, respectively; p &lt; 0.05). A decrease in percent area occupied by myofibrils was observed from PRE to VAR (−4.87%; p = 0.048), but not for the CON (4.53%; p = 0.979). In contrast, there was an increase in percent area occupied by non-contractile space from PRE to VAR (10.14%; p = 0.048), but not PRE to CON (0.72%; p = 0.979). In conclusion, while both RT protocols increased muscle fiber hypertrophy, a higher volume-load where RT variables were frequently manipulated increased non-contractile spacing in resistance-trained individuals.

scholarly journals Acute and chronic resistance training downregulates select LINE-1 retrotransposon activity markers in human skeletal muscle

2018 ◽  
Vol 314 (3) ◽  
pp. C379-C388 ◽  
Author(s):  
Matthew A. Romero ◽  
C. Brooks Mobley ◽  
Petey W. Mumford ◽  
Paul A. Roberson ◽  
Cody T. Haun ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Resistance Training ◽  
Resistance Exercise ◽  
Satellite Cell ◽  
Vastus Lateralis ◽  
Future Research ◽  
Resistance Training Program ◽  
Myoblast Proliferation ◽  
Retrotransposon Activity

Herein, we examined if acute or chronic resistance exercise affected markers of skeletal muscle long interspersed nuclear element-1 (LINE-1) retrotransposon activity. In study 1, 10 resistance-trained college-aged men performed three consecutive daily back squat sessions, and vastus lateralis biopsies were taken before (Pre), 2 h following session 1 (Post1), and 3 days following session 3 (Post2). In study 2, 13 untrained college-aged men performed a full-body resistance training program (3 days/wk), and vastus lateralis biopsies were taken before ( week 0) and ~72 h following training cessation ( week 12). In study 1, LINE-1 mRNA decreased 42–48% at Post1 and 2 ( P < 0.05), and reverse transcriptase (RT) activity trended downward at Post2 (−37%, P = 0.067). In study 2, LINE-1 mRNA trended downward at week 12 (−17%, P = 0.056) while LINE-1 promoter methylation increased (+142%, P = 0.041). Open reading frame (ORF)2p protein expression (−24%, P = 0.059) and RT activity (−26%, P = 0.063) also trended downward by week 12. Additionally, changes in RT activity versus satellite cell number were inversely associated ( r = −0.725, P = 0.008). Follow-up in vitro experiments demonstrated that 48-h treatments with lower doses (1 μM and 10 μM) of efavirenz and nevirapine (non-nucleoside RT inhibitors) increased myoblast proliferation ( P < 0.05). However, we observed a paradoxical decrease in myoblast proliferation with higher doses (50 μM) of efavirenz and delavirdine. This is the first report suggesting that resistance exercise downregulates markers of skeletal muscle LINE-1 activity. Given our discordant in vitro findings, future research is needed to thoroughly assess whether LINE-1-mediated RT activity enhances or blunts myoblast, or primary satellite cell, proliferative capacity.

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.

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.

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