Short-Term Training: When Do Repeated Bouts of Resistance Exercise Become Training?

2000 ◽  
Vol 25 (3) ◽  
pp. 185-193 ◽  
Author(s):  
Stuart M. Phillips
Keyword(s):  
Protein Synthesis ◽  
Resistance Exercise ◽  
Muscle Fibre ◽  
Time Course ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Cross Sectional ◽  
Volume Percentage ◽  
Muscle Balance ◽  
Induced Changes

Chronic resistance training induces increases in muscle fibre cross-sectional area (CSA), otherwise known as hypertrophy. This is due to an increased volume percentage of myofibrillar proteins within a given fibre. The exact time-course for muscle fibre hypertrophy is not well-documented but appears to require at least 6-7 weeks of regular resistive training at reasonably high intensity before increases in fibre CSA are deemed significant. Proposed training-induced changes in neural drive are hypothesized to increase strength due to increased synchrony of motor unit firing, reduced antagonist muscle activity and/or a reduction in any bilateral strength deficit. Nonetheless, increases in muscle protein synthesis were observed following an isolated bout of resistance exercise. In addition, muscle balance was positive, following resistance exercise when amino acids were infused/ingested. This showed that protein accretion occurred during the postexercise period. The implications of this hypothesis for training-induced increases in strength are discussed. Key words: hypertrophy, muscle protein synthesis, muscle protein breakdown, myofibrillar protein, strength.

Age-related Differences In Muscle Protein Synthesis And mTORC1 Signaling Following Resistance Exercise: A 24-hour Time-course

2010 ◽  
Vol 42 ◽  
pp. 63
Author(s):  
Christopher S. Fry ◽  
Micah J. Drummond ◽  
Erin L. Glynn ◽  
Jared M. Dickinson ◽  
David M. Gundermann ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Resistance Exercise ◽  
Time Course ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Age Related ◽  
Mtorc1 Signaling

THE TIME COURSE FOR ELEVATED MUSCLE PROTEIN SYNTHESIS FOLLOWING HEAVY RESISTANCE EXERCISE

1995 ◽  
Vol 27 (Supplement) ◽  
pp. S66
Author(s):  
J. D. MacDougall ◽  
M. Gibala ◽  
M. Tarnopolsky ◽  
J. MacDonald ◽  
S. Interisano ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Resistance Exercise ◽  
Time Course ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Heavy Resistance Exercise

Bigger weights may not beget bigger muscles: evidence from acute muscle protein synthetic responses after resistance exercise

2012 ◽  
Vol 37 (3) ◽  
pp. 551-554 ◽  
Author(s):  
Nicholas A. Burd ◽  
Cameron J. Mitchell ◽  
Tyler A. Churchward-Venne ◽  
Stuart M. Phillips
Keyword(s):  
Protein Synthesis ◽  
Resistance Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Muscle Growth ◽  
Exercise Recovery ◽  
Maximal Strength ◽  
Volitional Fatigue ◽  
Exercise Induced ◽  
Induced Changes

It is often recommended that heavier training intensities (∼70%–80% of maximal strength) be lifted to maximize muscle growth. However, we have reported that intensities as low as 30% of maximum strength, when lifted to volitional fatigue, are equally effective at stimulating muscle protein synthesis rates during resistance exercise recovery. This paper discusses the idea that high-intensity contractions are not the exclusive driver of resistance exercise-induced changes in muscle protein synthesis rates.

scholarly journals TIME COURSE OF MIXED MUSCLE PROTEIN SYNTHESIS FOLLOWING RESISTANCE EXERCISE IN HUMANS 1321

1997 ◽  
Vol 29 (Supplement) ◽  
pp. 230
Author(s):  
S. M. Phillips ◽  
K. D. Tipton ◽  
A. A. Aarsland ◽  
S. E. Wolf ◽  
R. R. Wolfe
Keyword(s):  
Protein Synthesis ◽  
Resistance Exercise ◽  
Time Course ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Exercise In Humans

Resistance training alters the response of fed state mixed muscle protein synthesis in young men

2008 ◽  
Vol 294 (1) ◽  
pp. R172-R178 ◽  
Author(s):  
Jason E. Tang ◽  
Jennifer G. Perco ◽  
Daniel R. Moore ◽  
Sarah B. Wilkinson ◽  
Stuart M. Phillips
Keyword(s):  
Protein Synthesis ◽  
Resistance Training ◽  
Resistance Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Young Men ◽  
Knee Extension ◽  
Type I ◽  
Cross Sectional ◽  
Fed State

Ten healthy young men (21.0 ± 1.5 yr, 1.79 ± 0.1 m, 82.7 ± 14.7 kg, means ± SD) participated in 8 wk of intense unilateral resistance training (knee extension exercise) such that one leg was trained (T) and the other acted as an untrained (UT) control. After the 8 wk of unilateral training, infusions of l-[ring-d5]phenylalanine, l-[ring-13C6]phenylalanine, and d3-α-ketoisocaproic acid were used to measure mixed muscle protein synthesis in the T and UT legs by the direct incorporation method [fractional synthetic rate (FSR)]. Protein synthesis was determined at rest as well as 4 h and 28 h after an acute bout of resistance exercise performed at the same intensity relative to the gain in single repetition maximum before and after training. Training increased mean muscle fiber cross-sectional area only in the T leg (type I: 16 ± 10%; type II: 20 ± 19%, P < 0.05). Acute resistance exercise increased muscle protein FSR in both legs at 4 h (T: 162 ± 76%; UT: 108 ± 62%, P < 0.01 vs. rest) with the increase in the T leg being significantly higher than in the UT leg at this time ( P < 0.01). At 28 h postexercise, FSR in the T leg had returned to resting levels; however, the rate of protein synthesis in the UT leg remained elevated above resting (70 ± 49%, P < 0.01). We conclude that resistance training attenuates the protein synthetic response to acute resistance exercise, despite higher initial increases in FSR, by shortening the duration for which protein synthesis is elevated.

scholarly journals The response of muscle protein synthesis following whole-body resistance exercise is greater following 40 g than 20 g of ingested whey protein

2016 ◽  
Vol 4 (15) ◽  
pp. e12893 ◽  
Author(s):  
Lindsay S. Macnaughton ◽  
Sophie L. Wardle ◽  
Oliver C. Witard ◽  
Chris McGlory ◽  
D. Lee Hamilton ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Resistance Exercise ◽  
Whey Protein ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Whole Body ◽  
Body Resistance

scholarly journals Resistance exercise maintains skeletal muscle protein synthesis during bed rest

1997 ◽  
Vol 82 (3) ◽  
pp. 807-810 ◽  
Author(s):  
Arny A. Ferrando ◽  
Kevin D. Tipton ◽  
Marcas M. Bamman ◽  
Robert R. Wolfe
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Resistance Training ◽  
Resistance Exercise ◽  
Lean Body Mass ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Bed Rest ◽  
Skeletal Muscle Protein ◽  
Skeletal Muscle Protein Synthesis

Ferrando, Arny A., Kevin D. Tipton, Marcas M. Bamman, and Robert R. Wolfe. Resistance exercise maintains skeletal muscle protein synthesis during bed rest. J. Appl. Physiol. 82(3): 807–810, 1997.—Spaceflight results in a loss of lean body mass and muscular strength. A ground-based model for microgravity, bed rest, results in a loss of lean body mass due to a decrease in muscle protein synthesis (MPS). Resistance training is suggested as a proposed countermeasure for spaceflight-induced atrophy because it is known to increase both MPS and skeletal muscle strength. We therefore hypothesized that scheduled resistance training throughout bed rest would ameliorate the decrease in MPS. Two groups of healthy volunteers were studied during 14 days of simulated microgravity. One group adhered to strict bed rest (BR; n = 5), whereas a second group engaged in leg resistance exercise every other day throughout bed rest (BREx; n = 6). MPS was determined directly by the incorporation of infusedl-[ ring-13C6]phenylalanine into vastus lateralis protein. After 14 days of bed rest, MPS in the BREx group did not change and was significantly greater than in the BR group. Thus moderate-resistance exercise can counteract the decrease in MPS during bed rest.

scholarly journals Exercise May Promote Skeletal Muscle Hypertrophy via Enhancing Leucine-Sensing: Preliminary Evidence

2021 ◽  
Vol 12 ◽  
Author(s):  
Yan Zhao ◽  
Jason Cholewa ◽  
Huayu Shang ◽  
Yueqin Yang ◽  
Xiaomin Ding ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Resistance Exercise ◽  
Aerobic Exercise ◽  
Protein Concentration ◽  
Muscle Hypertrophy ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Muscle Fibers ◽  
Mtor Signaling ◽  
Treadmill Running

Several studies have indicated a positive effect of exercise (especially resistance exercise) on the mTOR signaling that control muscle protein synthesis and muscle remodeling. However, the relationship between exercise, mTOR activation and leucine-sensing requires further clarification. Two month old Sprague-Dawley rats were subjected to aerobic exercise (treadmill running at 20 m/min, 6° incline for 60 min) and resistance exercise (incremental ladder climbing) for 4 weeks. The gastrocnemius muscles were removed for determination of muscle fibers diameter, cross-sectional area (CSA), protein concentration and proteins involved in muscle leucine-sensing and protein synthesis. The results show that 4 weeks of resistance exercise increased the diameter and CSA of gastrocnemius muscle fibers, protein concentration, the phosphorylation of mTOR (Ser2448), 4E-BP1(Thr37/46), p70S6K (Thr389), and the expression of LeuRS, while aerobic exercise just led to a significant increase in protein concentration and the phosphorylation of 4E-BP1(Thr37/46). Moreover, no difference was found for Sestrin2 expression between groups. The current study shows resistance exercise, but not aerobic exercise, may increase muscle protein synthesis and protein deposition, and induces muscle hypertrophy through LeuRS/mTOR signaling pathway. However, further studies are still warranted to clarify the exact effects of vary intensities and durations of aerobic exercise training.

Sign in / Sign up

Export Citation Format

Share Document