scholarly journals Essential amino acids and muscle protein recovery from resistance exercise

2002 ◽  
Vol 283 (4) ◽  
pp. E648-E657 ◽  
Author(s):  
Elisabet Børsheim ◽  
Kevin D. Tipton ◽  
Steven E. Wolf ◽  
Robert R. Wolfe
Keyword(s):  
Amino Acids ◽  
Resistance Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Vastus Lateralis ◽  
Area Under The Curve ◽  
Essential Amino Acids ◽  
Constant Infusion ◽  
Protein Balance ◽  
Dose Dependent

This study tests the hypothesis that a dose of 6 g of orally administered essential amino acids (EAAs) stimulates net muscle protein balance in healthy volunteers when consumed 1 and 2 h after resistance exercise. Subjects received a primed constant infusion ofl-[2H5]phenylalanine andl-[1-13C]leucine. Samples from femoral artery and vein and biopsies from vastus lateralis were obtained. Arterial EAA concentrations increased severalfold after drinks. Net muscle protein balance (NB) increased proportionally more than arterial AA concentrations in response to drinks, and it returned rapidly to basal values when AA concentrations decreased. Area under the curve for net phenylalanine uptake above basal value was similar for the first hour after each drink (67 ± 17 vs. 77 ± 20 mg/leg, respectively). Because the NB response was double the response to two doses of a mixture of 3 g of EAA + 3 g of nonessential AA (NEAA) (14), we conclude that NEAA are not necessary for stimulation of NB and that there is a dose-dependent effect of EAA ingestion on muscle protein synthesis.

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 Postexercise net protein synthesis in human muscle from orally administered amino acids

1999 ◽  
Vol 276 (4) ◽  
pp. E628-E634 ◽  
Author(s):  
Kevin D. Tipton ◽  
Arny A. Ferrando ◽  
Stuart M. Phillips ◽  
David Doyle ◽  
Robert R. Wolfe
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Resistance Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Random Order ◽  
Essential Amino Acids ◽  
Constant Infusion ◽  
Protein Balance

We examined the response of net muscle protein synthesis to ingestion of amino acids after a bout of resistance exercise. A primed, constant infusion ofl-[ ring-2H5]phenylalanine was used to measure net muscle protein balance in three male and three female volunteers on three occasions. Subjects consumed in random order 1 liter of 1) a mixed amino acid (40 g) solution (MAA), 2) an essential amino acid (40 g) solution (EAA), and 3) a placebo solution (PLA). Arterial amino acid concentrations increased ∼150–640% above baseline during ingestion of MAA and EAA. Net muscle protein balance was significantly increased from negative during PLA ingestion (−50 ± 23 nmol ⋅ min−1 ⋅ 100 ml leg volume−1) to positive during MAA ingestion (17 ± 13 nmol ⋅ min−1 ⋅ 100 ml leg volume−1) and EAA (29 ± 14 nmol ⋅ min−1 ⋅ 100 ml leg volume−1; P < 0.05). Because net balance was similar for MAA and EAA, it does not appear necessary to include nonessential amino acids in a formulation designed to elicit an anabolic response from muscle after exercise. We concluded that ingestion of oral essential amino acids results in a change from net muscle protein degradation to net muscle protein synthesis after heavy resistance exercise in humans similar to that seen when the amino acids were infused.

scholarly journals Increased net muscle protein balance in response to simultaneous and separate ingestion of carbohydrate and essential amino acids following resistance exercise

2014 ◽  
Vol 39 (3) ◽  
pp. 329-339 ◽  
Author(s):  
Oliver C. Witard ◽  
Tara L. Cocke ◽  
Arny A. Ferrando ◽  
Robert R. Wolfe ◽  
Kevin D. Tipton
Keyword(s):  
Amino Acids ◽  
Resistance Exercise ◽  
Acute Exercise ◽  
Muscle Protein ◽  
Exercise Bout ◽  
Essential Amino Acids ◽  
Delayed Response ◽  
Protein Balance ◽  
Post Exercise ◽  
Exercise Muscle

Relative to essential amino acids (EAAs), carbohydrate (CHO) ingestion stimulates a delayed response of net muscle protein balance (NBAL). We investigated if staggered ingestion of CHO and EAA would superimpose the response of NBAL following resistance exercise, thus resulting in maximal anabolic stimulation. Eight recreationally trained subjects completed 2 trials: combined (COMB — drink 1, CHO+EAA; drink 2, placebo) and separated (SEP — drink 1, CHO; drink 2, EAA) post-exercise ingestion of CHO and EAA. Drink 1 was administered 1 h following an acute exercise bout and was followed 1 h later by drink 2. A primed, continuous infusion of l-[ring-13C6]-phenylalanine was combined with femoral arteriovenous sampling and muscle biopsies for the determination of muscle protein kinetics. Arterial amino acid concentrations increased following ingestion of EAA in both conditions. No difference between conditions was observed for phenylalanine delivery to the leg (COMB: 167 ± 23 μmol·min−1·(100 mL leg vol)−1 × 6 h; SEP: 167 ± 21 μmol·min−1·(100 mL leg vol)−1 × 6 h, P > 0.05). In the first hour following ingestion of the drink containing EAA, phenylalanine uptake was 50% greater for the SEP trial than the COMB trial. However, phenylalanine uptake was similar for COMB (110 ± 19 mg) and SEP (117 ± 24 mg) over the 6 h period. These data suggest that whereas separation of CHO and EAA ingestion following exercise may have a transient physiological impact on NBAL, this response is not reflected over a longer period. Thus, separation of CHO and EAA ingestion is unnecessary to optimize post-exercise muscle protein metabolism.

scholarly journals Nutritional and contractile regulation of human skeletal muscle protein synthesis and mTORC1 signaling

2009 ◽  
Vol 106 (4) ◽  
pp. 1374-1384 ◽  
Author(s):  
Micah J. Drummond ◽  
Hans C. Dreyer ◽  
Christopher S. Fry ◽  
Erin L. Glynn ◽  
Blake B. Rasmussen
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Protein Synthesis ◽  
Resistance Exercise ◽  
Human Skeletal Muscle ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Essential Amino Acids ◽  
Skeletal Muscle Protein ◽  
Mtorc1 Signaling

In this review we discuss current findings in the human skeletal muscle literature describing the acute influence of nutrients (leucine-enriched essential amino acids in particular) and resistance exercise on muscle protein synthesis and mammalian target of rapamycin complex 1 (mTORC1) signaling. We show that essential amino acids and an acute bout of resistance exercise independently stimulate human skeletal muscle protein synthesis. It also appears that ingestion of essential amino acids following resistance exercise leads to an even larger increase in the rate of muscle protein synthesis compared with the independent effects of nutrients or muscle contraction. Until recently the cellular mechanisms responsible for controlling the rate of muscle protein synthesis in humans were unknown. In this review, we highlight new studies in humans that have clearly shown the mTORC1 signaling pathway is playing an important regulatory role in controlling muscle protein synthesis in response to nutrients and/or muscle contraction. We propose that essential amino acid ingestion shortly following a bout of resistance exercise is beneficial in promoting skeletal muscle growth and may be useful in counteracting muscle wasting in a variety of conditions such as aging, cancer cachexia, physical inactivity, and perhaps during rehabilitation following trauma or surgery.

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.

scholarly journals Skeletal muscle protein anabolic response to resistance exercise and essential amino acids is delayed with aging

2008 ◽  
Vol 104 (5) ◽  
pp. 1452-1461 ◽  
Author(s):  
Micah J. Drummond ◽  
Hans C. Dreyer ◽  
Bart Pennings ◽  
Christopher S. Fry ◽  
Shaheen Dhanani ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Resistance Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Essential Amino Acids ◽  
Skeletal Muscle Protein ◽  
Eif2α Phosphorylation ◽  
Increased Risk ◽  
Old Men

Skeletal muscle loss during aging leads to an increased risk of falls, fractures, and eventually loss of independence. Resistance exercise is a useful intervention to prevent sarcopenia; however, the muscle protein synthesis (MPS) response to resistance exercise is less in elderly compared with young subjects. On the other hand, essential amino acids (EAA) increase MPS equally in both young and old subjects when sufficient EAA is ingested. We hypothesized that EAA ingestion following a bout of resistance exercise would stimulate anabolic signaling and MPS similarly between young and old men. Each subject ingested 20 g of EAA 1 h following leg resistance exercise. Muscle biopsies were obtained before and 1, 3, and 6 h after exercise to measure the rate of MPS and signaling pathways that regulate translation initiation. MPS increased early in young (1–3 h postexercise) and later in old (3–6 h postexercise). At 1 h postexercise, ERK1/2 MNK1 phosphorylation increased and eIF2α phosphorylation decreased only in the young. mTOR signaling (mTOR, S6K1, 4E-BP1, eEF2) was similar between groups at all time points, but MNK1 phosphorylation was lower at 3 h and AMP-activated protein kinase-α (AMPKα) phosphorylation was higher in old 1–3 h postexercise. We conclude that the acute MPS response after resistance exercise and EAA ingestion is similar between young and old men; however, the response is delayed with aging. Unresponsive ERK1/2 signaling and AMPK activation in old muscle may be playing a role in the delayed activation of MPS. Notwithstanding, the combination of resistance exercise and EAA ingestion should be a useful strategy to combat sarcopenia.

scholarly journals An oral essential amino acid-carbohydrate supplement enhances muscle protein anabolism after resistance exercise

2000 ◽  
Vol 88 (2) ◽  
pp. 386-392 ◽  
Author(s):  
Blake B. Rasmussen ◽  
Kevin D. Tipton ◽  
Sharon L. Miller ◽  
Steven E. Wolf ◽  
Robert R. Wolfe
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Resistance Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Venous Blood ◽  
Compartment Model ◽  
Essential Amino Acids

This study was designed to determine the response of muscle protein to the bolus ingestion of a drink containing essential amino acids and carbohydrate after resistance exercise. Six subjects (3 men, 3 women) randomly consumed a treatment drink (6 g essential amino acids, 35 g sucrose) or a flavored placebo drink 1 h or 3 h after a bout of resistance exercise on two separate occasions. We used a three-compartment model for determination of leg muscle protein kinetics. The model involves the infusion of ring-2H5-phenylalanine, femoral arterial and venous blood sampling, and muscle biopsies. Phenylalanine net balance and muscle protein synthesis were significantly increased above the predrink and corresponding placebo value ( P < 0.05) when the drink was taken 1 or 3 h after exercise but not when the placebo was ingested at 1 or 3 h. The response to the amino acid-carbohydrate drink produced similar anabolic responses at 1 and 3 h. Muscle protein breakdown did not change in response to the drink. We conclude that essential amino acids with carbohydrates stimulate muscle protein anabolism by increasing muscle protein synthesis when ingested 1 or 3 h after resistance exercise.

scholarly journals Acute response of net muscle protein balance reflects 24-h balance after exercise and amino acid ingestion

2003 ◽  
Vol 284 (1) ◽  
pp. E76-E89 ◽  
Author(s):  
Kevin D. Tipton ◽  
Elisabet Borsheim ◽  
Steven E. Wolf ◽  
Arthur P. Sanford ◽  
Robert R. Wolfe
Keyword(s):  
Amino Acids ◽  
Resistance Exercise ◽  
Muscle Protein ◽  
Essential Amino Acids ◽  
Protein Balance ◽  
Muscle Response ◽  
Acute Response ◽  
Synthetic Rate ◽  
Fractional Synthetic Rate ◽  
The Difference

The purpose of this study was to determine if the acute anabolic muscle response to resistance exercise and essential amino acids (EAA) reflects the response over 24 h. Seven subjects participated in the following two 24-h studies: 1) resting (REST) and 2) rest plus resistance exercise and consumption of EAA (ES). Net balance (NB) across the leg was determined for four amino acids. [13C6]phenylalanine was infused to determine mixed muscle fractional synthetic rate (FSR). Twenty-four-hour FSR was significantly greater for ES than for REST ( P = 0.003). Exchange of phenylalanine across the leg was −194 ± 74 (SE) mg for ES and −371 ± 88 mg for REST ( P = 0.07) over 24 h and 229 ± 42 mg (ES) and 28 ± 15 mg (REST; P < 0.01) over 3 h corresponding to exercise and EAA consumption for ES. The difference in phenylalanine exchange between REST and ES was not different for measurements over 24 and 3 h. Increases in NB during ES were primarily the result of increases in protein synthesis. Results for other amino acids were similar. The acute anabolic response of muscle to EAA intake and exercise is additive to the response at rest and thus reflects the 24-h response.

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.

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