scholarly journals Resistance exercise load does not determine training-mediated hypertrophic gains in young men

2012 ◽  
Vol 113 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Cameron J. Mitchell ◽  
Tyler A. Churchward-Venne ◽  
Daniel W. D. West ◽  
Nicholas A. Burd ◽  
Leigh Breen ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Resistance Exercise ◽  
Acute Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Vastus Lateralis ◽  
Muscle Volume ◽  
Maximal Strength ◽  
Heavy Load ◽  
Exercise Load

We have reported that the acute postexercise increases in muscle protein synthesis rates, with differing nutritional support, are predictive of longer-term training-induced muscle hypertrophy. Here, we aimed to test whether the same was true with acute exercise-mediated changes in muscle protein synthesis. Eighteen men (21 ± 1 yr, 22.6 ± 2.1 kg/m2; means ± SE) had their legs randomly assigned to two of three training conditions that differed in contraction intensity [% of maximal strength (1 repetition maximum)] or contraction volume (1 or 3 sets of repetitions): 30%-3, 80%-1, and 80%-3. Subjects trained each leg with their assigned regime for a period of 10 wk, 3 times/wk. We made pre- and posttraining measures of strength, muscle volume by magnetic resonance (MR) scans, as well as pre- and posttraining biopsies of the vastus lateralis, and a single postexercise (1 h) biopsy following the first bout of exercise, to measure signaling proteins. Training-induced increases in MR-measured muscle volume were significant ( P < 0.01), with no difference between groups: 30%-3 = 6.8 ± 1.8%, 80%-1 = 3.2 ± 0.8%, and 80%-3= 7.2 ± 1.9%, P = 0.18. Isotonic maximal strength gains were not different between 80%-1 and 80%-3, but were greater than 30%-3 ( P = 0.04), whereas training-induced isometric strength gains were significant but not different between conditions ( P = 0.92). Biopsies taken 1 h following the initial resistance exercise bout showed increased phosphorylation ( P < 0.05) of p70S6K only in the 80%-1 and 80%-3 conditions. There was no correlation between phosphorylation of any signaling protein and hypertrophy. In accordance with our previous acute measurements of muscle protein synthetic rates a lower load lifted to failure resulted in similar hypertrophy as a heavy load lifted to failure.

Resistance exercise acutely increases MHC and mixed muscle protein synthesis rates in 78–84 and 23–32 yr olds

2000 ◽  
Vol 278 (4) ◽  
pp. E620-E626 ◽  
Author(s):  
Debbie L. Hasten ◽  
Jina Pak-Loduca ◽  
Kathleen A. Obert ◽  
Kevin E. Yarasheski
Keyword(s):  
Protein Synthesis ◽  
Resistance Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Vastus Lateralis ◽  
Weight Lifting ◽  
Synthesis Rate ◽  
Vastus Lateralis Muscle ◽  
Short Term ◽  
Mixed Protein

We determined whether short-term weight-lifting exercise increases the synthesis rate of the major contractile proteins, myosin heavy chain (MHC), actin, and mixed muscle proteins in nonfrail elders and younger women and men. Fractional synthesis rates of mixed, MHC, and actin proteins were determined in seven healthy sedentary 23- to 32-yr-old and seven healthy 78- to 84-yr-old participants in paired studies done before and at the end of a 2-wk weight-lifting program. The in vivo rate of incorporation of 1-[13C]leucine into vastus lateralis MHC, actin, and mixed proteins was determined using a 14-h constant intravenous infusion of 1-[13C]leucine. Before exercise, the mixed and MHC fractional synthetic rates were lower in the older than in the younger participants ( P ≤ 0.04). Baseline actin protein synthesis rates were similar in the two groups ( P = not significant). Over a 2-wk period, participants completed ten 1- to 1.5-h weight-lifting exercise sessions: 2–3 sets per day of 9 exercises, 8–12 repetitions per set, at 60–90% of maximum voluntary muscle strength. At the end of exercise, MHC and mixed protein synthetic rates increased in the younger (88 and 121%) and older participants (105 and 182%; P < 0.001 vs. baseline). These findings indicate that MHC and mixed protein synthesis rates are reduced more than actin in advanced age. Similar to that of 23–32 yr olds, the vastus lateralis muscle in 78–84 yr olds retains the capacity to increase MHC and mixed protein synthesis rates in response to short-term resistance exercise.

Effect of an Amino Acid, Protein, and Carbohydrate Mixture on Net Muscle Protein Balance after Resistance Exercise

2004 ◽  
Vol 14 (3) ◽  
pp. 255-271 ◽  
Author(s):  
Elisabet Børsheim ◽  
Asle Aarsland ◽  
Robert R. Wolfe
Keyword(s):  
Protein Synthesis ◽  
Resistance Exercise ◽  
Whey Protein ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Vastus Lateralis ◽  
Area Under The Curve ◽  
Constant Infusion ◽  
Delayed Response ◽  
Protein Balance

This study tests the hypotheses that (a) a mixture of whey protein, amino acids (AA), and carbohydrates (CHO) stimulates net muscle protein synthesis to a greater extent than isoenergetic CHO alone after resistance exercise; and (b) that the stimulatory effect of a protein, AA, and CHO mixture will last beyond the 1 st hour after intake. Eight subjects participated in 2 trials. In one (PAAC), they ingested 77.4 g CHO, 17.5 g whey protein, and 4.9 g AA 1 hr after resistance exercise. In the other (CON), 100 g CHO was ingested instead. They received a primed constant infusion of L-[2H5]-phenylalanine, and samples from femoral artery and vein, and biopsies from vastus lateralis were obtained. The area under the curve for net uptake of phenylalanine into muscle above pre-drink value was 128 ±42 mg • leg-1 (PAAC) versus 32 ± 10 mg - leg-1 (CON) for the 3 hr after the drink (p = .04). The net protein balance response to the mixture consisted of two components, one rapid immediate response, and a smaller delayed response about 90 min after drink, whereas in CON only a small delayed response was seen. We conclude that after resistance exercise, a mixture of whey protein, AA, and CHO stimulated muscle protein synthesis to a greater extent than isoenergetic CHO alone. Further, compared to previously reported findings, the addition of protein to an AA + CHO mixture seems to extend the anabolic effect.

scholarly journals Effect of a cyclooxygenase-2 inhibitor on postexercise muscle protein synthesis in humans

2010 ◽  
Vol 298 (2) ◽  
pp. E354-E361 ◽  
Author(s):  
Nicholas A. Burd ◽  
Jared M. Dickinson ◽  
Jennifer K. LeMoine ◽  
Chad C. Carroll ◽  
Bridget E. Sullivan ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Resistance Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Vastus Lateralis ◽  
Constant Infusion ◽  
Synthesis Rate ◽  
Cox 2 ◽  
Cox 1

Nonselective blockade of the cyclooxygenase (COX) enzymes in skeletal muscle eliminates the normal increase in muscle protein synthesis following resistance exercise. The current study tested the hypothesis that this COX-mediated increase in postexercise muscle protein synthesis is regulated specifically by the COX-2 isoform. Sixteen males (23 ± 1 yr) were randomly assigned to one of two groups that received three doses of either a selective COX-2 inhibitor (celecoxib; 200 mg/dose, 600 mg total) or a placebo in double-blind fashion during the 24 h following a single bout of knee extensor resistance exercise. At rest and 24 h postexercise, skeletal muscle protein fractional synthesis rate (FSR) was measured using a primed constant infusion of [2H5]phenylalanine coupled with muscle biopsies of the vastus lateralis, and measurements were made of mRNA and protein expression of COX-1 and COX-2. Mixed muscle protein FSR in response to exercise ( P < 0.05) was not suppressed by the COX-2 inhibitor (0.056 ± 0.004 to 0.108 ± 0.014%/h) compared with placebo (0.074 ± 0.004 to 0.091 ± 0.005%/h), nor was there any difference ( P > 0.05) between the placebo and COX-2 inhibitor postexercise when controlling for resting FSR. The COX-2 inhibitor did not influence COX-1 mRNA, COX-1 protein, or COX-2 protein levels, whereas it did increase ( P < 0.05) COX-2 mRNA (3.0 ± 0.9-fold) compared with placebo (1.3 ± 0.3-fold). It appears that the elimination of the postexercise muscle protein synthesis response by nonselective COX inhibitors is not solely due to COX-2 isoform blockade. Furthermore, the current data suggest that the COX-1 enzyme is likely the main isoform responsible for the COX-mediated increase in muscle protein synthesis following resistance exercise in humans.

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 A comparison of 2H2O and phenylalanine flooding dose to investigate muscle protein synthesis with acute exercise in rats

2009 ◽  
Vol 297 (1) ◽  
pp. E252-E259 ◽  
Author(s):  
Heath G. Gasier ◽  
Steven E. Riechman ◽  
Michael P. Wiggs ◽  
Stephen F. Previs ◽  
James D. Fluckey
Keyword(s):  
Protein Synthesis ◽  
Resistance Exercise ◽  
High Intensity ◽  
Acute Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Primary Objective ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Single Bout

The primary objective of this investigation was to determine whether 2H2O and phenylalanine (Phe) flooding dose methods yield comparable fractional rates of protein synthesis (FSR) in skeletal muscle following a single bout of high-intensity resistance exercise (RE). Sprague-Dawley rats were assigned by body mass to either 4-h control (CON 4 h; n = 6), 4-h resistance exercise (RE 4 h; n = 6), 24-h control (CON 24 h; n = 6), or 24-h resistance exercise (RE 24 h; n = 6). The RE groups were operantly conditioned to engage in a single bout of high-intensity, “squat-like” RE. All rats were given an intraperitoneal injection of 99.9% 2H2O and provided 4.0% 2H2O drinking water for either 24 ( n = 12) or 4 h ( n = 12) prior to receiving a flooding dose of l-[2,3,4,5,6-3H]Phe 16 h post-RE. Neither method detected an effect of RE on FSR in the mixed gastrocnemius, plantaris, or soleus muscle. Aside from the qualitative similarities between methods, the 4-h 2H2O FSR measurements, when expressed in percent per hour, were quantitatively greater than the 24-h 2H2O and Phe flooding in all muscles ( P < 0.001), and the 24-h 2H2O was greater than the Phe flooding dose in the mixed gastrocnemius and plantaris ( P < 0.05). In contrast, the actual percentage of newly synthesized protein was significantly higher in the 24- vs. 4-h 2H2O and Phe flooding dose groups ( P < 0.001). These results suggest that the methodologies provide “qualitatively” similar results when a perturbation such as RE is studied. However, due to potential quantitative differences between methods, the experimental question should determine what approach should be used.

scholarly journals Effect of carbohydrate intake on net muscle protein synthesis during recovery from resistance exercise

2004 ◽  
Vol 96 (2) ◽  
pp. 674-678 ◽  
Author(s):  
Elisabet Børsheim ◽  
Melanie G. Cree ◽  
Kevin D. Tipton ◽  
Tabatha A. Elliott ◽  
Asle Aarsland ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Resistance Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Vastus Lateralis ◽  
Exercise Bout ◽  
Protein Breakdown ◽  
Protein Balance ◽  
Muscle Biopsies ◽  
Placebo Drink

The purpose of this study was to determine the effect of ingestion of 100 g of carbohydrates on net muscle protein balance (protein synthesis minus protein breakdown) after resistance exercise. Two groups of eight subjects performed a resistance exercise bout (10 sets of 8 repetitions of leg presses at 80% of 1-repetition maximum) before they rested in bed for 4 h. One group (CHO) received a drink consisting of 100 g of carbohydrates 1 h postexercise. The other group (Pla) received a noncaloric placebo drink. Leg amino acid metabolism was determined by infusion of 2H5- or 13C6-labeled phenylalanine, sampling from femoral artery and vein, and muscle biopsies from vastus lateralis. Drink intake did not affect arterial insulin concentration in Pla, whereas insulin increased several times after the drink in CHO ( P < 0.05 vs. Pla). Arterial phenylalanine concentration fell slightly after the drink in CHO. Net muscle protein balance between synthesis and breakdown did not change in Pla, whereas it improved in CHO from -17 ± 3 nmol·ml-1·100 ml leg-1 before drink to an average of -4 ± 4 and 0 ± 3 nmol·ml-1·100 ml leg-1 during the second and third hour after the drink, respectively ( P < 0.05 vs. Pla during last hour). The improved net balance in CHO was due primarily to a progressive decrease in muscle protein breakdown. We conclude that ingestion of carbohydrates improved net leg protein balance after resistance exercise. However, the effect was minor and delayed compared with the previously reported effect of ingestion of amino acids.

scholarly journals Timing of amino acid-carbohydrate ingestion alters anabolic response of muscle to resistance exercise

2001 ◽  
Vol 281 (2) ◽  
pp. E197-E206 ◽  
Author(s):  
Kevin D. Tipton ◽  
Blake B. Rasmussen ◽  
Sharon L. Miller ◽  
Steven E. Wolf ◽  
Sharla K. Owens-Stovall ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Resistance Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Vastus Lateralis ◽  
Healthy Human ◽  
Anabolic Response ◽  
Carbohydrate Ingestion

The present study was designed to determine whether consumption of an oral essential amino acid-carbohydrate supplement (EAC) before exercise results in a greater anabolic response than supplementation after resistance exercise. Six healthy human subjects participated in two trials in random order, PRE (EAC consumed immediately before exercise), and POST (EAC consumed immediately after exercise). A primed, continuous infusion ofl-[ ring-2H5]phenylalanine, femoral arteriovenous catheterization, and muscle biopsies from the vastus lateralis were used to determine phenylalanine concentrations, enrichments, and net uptake across the leg. Blood and muscle phenylalanine concentrations were increased by ∼130% after drink consumption in both trials. Amino acid delivery to the leg was increased during exercise and remained elevated for the 2 h after exercise in both trials. Delivery of amino acids (amino acid concentration times blood flow) was significantly greater in PRE than in POST during the exercise bout and in the 1st h after exercise ( P < 0.05). Total net phenylalanine uptake across the leg was greater ( P = 0.0002) during PRE (209 ± 42 mg) than during POST (81 ± 19). Phenylalanine disappearance rate, an indicator of muscle protein synthesis from blood amino acids, increased after EAC consumption in both trials. These results indicate that the response of net muscle protein synthesis to consumption of an EAC solution immediately before resistance exercise is greater than that when the solution is consumed after exercise, primarily because of an increase in muscle protein synthesis as a result of increased delivery of amino acids to the leg.

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.

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