Dose-Dependent Effects of Protein Ingestion and Resistance Exercise on Muscle Protein Synthesis in Aging Adults: A Literature Review

The myofibrillar protein synthesis (MPS) response to resistance exercise (REX) and protein ingestion during energy deficit (ED) is unknown. In young men ( n = 8) and women ( n = 7), we determined protein signaling and resting postabsorptive MPS during energy balance [EB; 45 kcal·kg fat-free mass (FFM)−1·day−1] and after 5 days of ED (30 kcal·kg FFM−1·day−1) as well as MPS while in ED after acute REX in the fasted state and with the ingestion of whey protein (15 and 30 g). Postabsorptive rates of MPS were 27% lower in ED than EB ( P < 0.001), but REX stimulated MPS to rates equal to EB. Ingestion of 15 and 30 g of protein after REX in ED increased MPS ∼16 and ∼34% above resting EB ( P < 0.02). p70 S6K Thr389 phosphorylation increased above EB only with combined exercise and protein intake (∼2–7 fold, P < 0.05). In conclusion, short-term ED reduces postabsorptive MPS; however, a bout of REX in ED restores MPS to values observed at rest in EB. The ingestion of protein after REX further increases MPS above resting EB in a dose-dependent manner. We conclude that combining REX with increased protein availability after exercise enhances rates of skeletal muscle protein synthesis during short-term ED and could in the long term preserve muscle mass.

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Protein ingestion increases muscle protein synthesis after, but not during, endurance exercise

British Journal of Sports Medicine ◽

10.1136/bjsm.2010.078972.19 ◽

2010 ◽

Vol 44 (14) ◽

pp. i6-i7 ◽

Cited By ~ 1

Author(s):

C. Hulston ◽

E. Wolsk ◽

T. Grondahl ◽

C. Yfanti ◽

G. van Hall

Keyword(s):

Protein Synthesis ◽

Endurance Exercise ◽

Muscle Protein ◽

Muscle Protein Synthesis ◽

Protein Ingestion

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

Physiological Reports ◽

10.14814/phy2.12893 ◽

2016 ◽

Vol 4 (15) ◽

pp. e12893 ◽

Cited By ~ 75

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

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Resistance exercise maintains skeletal muscle protein synthesis during bed rest

Journal of Applied Physiology ◽

10.1152/jappl.1997.82.3.807 ◽

1997 ◽

Vol 82 (3) ◽

pp. 807-810 ◽

Cited By ~ 147

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.

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

Frontiers in Physiology ◽

10.3389/fphys.2021.741038 ◽

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.

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