scholarly journals Dose-Dependent Increases in Whole-Body Net Protein Balance and Dietary Protein-Derived Amino Acid Incorporation into Myofibrillar Protein During Recovery from Resistance Exercise in Older Men

2019 ◽  
Vol 149 (2) ◽  
pp. 221-230 ◽  
Author(s):  
Andrew M Holwerda ◽  
Kevin J M Paulussen ◽  
Maarten Overkamp ◽  
Joy P B Goessens ◽  
Irene Fleur Kramer ◽  
...  

ABSTRACT Background Age-related decline in skeletal muscle mass is at least partly attributed to anabolic resistance to food intake. Resistance exercise sensitizes skeletal muscle tissue to the anabolic properties of amino acids. Objective The present study assessed protein digestion and amino acid absorption kinetics, whole-body protein balance, and the myofibrillar protein synthetic response to ingestion of different amounts of protein during recovery from resistance exercise in older men. Methods Forty-eight healthy older men [mean ± SEM age: 66 ± 1 y; body mass index (kg/m2): 25.4 ± 0.3] were randomly assigned to ingest 0, 15, 30, or 45 g milk protein concentrate after a single bout of resistance exercise consisting of 4 sets of 10 repetitions of leg press and leg extension and 2 sets of 10 repetitions of lateral pulldown and chest press performed at 75–80% 1-repetition maximum. Postprandial protein digestion and amino acid absorption kinetics, whole-body protein metabolism, and myofibrillar protein synthesis rates were assessed using primed, continuous infusions of l-[ring-2H5]-phenylalanine, l-[ring-2H2]-tyrosine, and l-[1-13C]-leucine combined with ingestion of intrinsically l-[1-13C]-phenylalanine and l-[1-13C]-leucine labeled protein. Results Whole-body net protein balance showed a dose-dependent increase after ingestion of 0, 15, 30, or 45 g of protein (0.015 ± 0.002, 0.108 ± 0.004, 0.162 ± 0.008, and 0.215 ± 0.009 μmol Phe · kg−1 · min−1, respectively; P < 0.001). Myofibrillar protein synthesis rates were higher after ingesting 30 (0.0951% ± 0.0062%/h, P = 0.07) or 45 g of protein (0.0970% ± 0.0062%/h, P < 0.05) than after 0 g (0.0746% ± 0.0051%/h). Incorporation of dietary protein–derived amino acids (l-[1-13C]-phenylalanine) into de novo myofibrillar protein showed a dose-dependent increase after ingestion of 15, 30, or 45 g protein (0.0171 ± 0.0017, 0.0296 ± 0.0030, and 0.0397 ± 0.0026 mole percentage excess, respectively; P < 0.05). Conclusions Dietary protein ingested during recovery from resistance exercise is rapidly digested and absorbed. Whole-body net protein balance and dietary protein-derived amino acid incorporation into myofibrillar protein show dose-dependent increases. Ingestion of ≥30 g protein increases postexercise myofibrillar protein synthesis rates in older men. This trial was registered at Nederlands Trial Register as NTR4492.

2018 ◽  
Vol 314 (5) ◽  
pp. E457-E467 ◽  
Author(s):  
Jorn Trommelen ◽  
Imre W. K. Kouw ◽  
Andrew M. Holwerda ◽  
Tim Snijders ◽  
Shona L. Halson ◽  
...  

The purpose of this study was to determine the impact of ingesting 30 g casein protein with and without 2 g free leucine before sleep on myofibrillar protein synthesis rates during postexercise overnight recovery. Thirty-six healthy young men performed a single bout of resistance-type exercise in the evening (1945) after a full day of dietary standardization. Thirty minutes before sleep (2330), subjects ingested 30 g intrinsically l-[1-13C]phenylalanine-labeled protein with (PRO+leu, n = 12) or without (PRO, n = 12) 2 g free leucine, or a noncaloric placebo (PLA, n = 12). Continuous intravenous l-[ ring-2H5]phenylalanine, l-[1-13C]leucine, and l-[ ring-2H2]tyrosine infusions were applied. Blood and muscle tissue samples were collected to assess whole body protein net balance, myofibrillar protein synthesis rates, and overnight incorporation of dietary protein-derived amino acids into myofibrillar protein. Protein ingestion before sleep improved overnight whole body protein net balance ( P < 0.001). Myofibrillar protein synthesis rates did not differ significantly between treatments as assessed by l-[ ring-2H5]phenylalanine (0.057 ± 0.002, 0.055 ± 0.002, and 0.055 ± 0.004%/h for PLA, PRO, and PRO+leu, respectively; means ± SE; P = 0.850) or l-[1-13C]leucine (0.080 ± 0.004, 0.073 ± 0.004, and 0.083 ± 0.006%/h, respectively; P = 0.328). Myofibrillar l-[1-13C]phenylalanine enrichments increased following protein ingestion but did not differ between the PRO and PRO+leu treatments. In conclusion, protein ingestion before sleep improves whole body protein net balance and provides amino acids that are incorporated into myofibrillar protein during sleep. However, the ingestion of 30 g casein protein with or without additional free leucine before sleep does not increase muscle protein synthesis rates during postexercise overnight recovery.


2019 ◽  
Vol 149 (9) ◽  
pp. 1533-1542 ◽  
Author(s):  
Imre W K Kouw ◽  
Jan Willem van Dijk ◽  
Astrid M H Horstman ◽  
Irene Fleur Kramer ◽  
Joy P B Goessens ◽  
...  

ABSTRACT Background Excess lipid availability has been associated with the development of anabolic resistance. As such, obesity may be accompanied by impairments in muscle protein metabolism. Objective We hypothesized that basal and postprandial muscle protein synthesis rates are lower in obese than in lean men. Methods Twelve obese men [mean ± SEM age: 48 ± 2 y; BMI (in kg/m2): 37.0 ± 1.5; body fat: 32 ± 2%] and 12 age-matched lean controls (age: 43 ± 3 y; BMI: 23.4 ± 0.4; body fat: 21 ± 1%) received primed continuous L-[ring-2H5]-phenylalanine and L-[ring-3,5-2H2]-tyrosine infusions and ingested 25 g intrinsically L-[1-13C]-phenylalanine labeled whey protein. Repeated blood and muscle samples were obtained to assess protein digestion and amino acid absorption kinetics, and basal and postprandial myofibrillar protein synthesis rates. Results Exogenous phenylalanine appearance rates increased after protein ingestion in both groups (P < 0.001), with a total of 53 ± 1% and 53 ± 2% of dietary protein–derived phenylalanine appearing in the circulation over the 5-h postprandial period in lean and obese men, respectively (P = 0.82). After protein ingestion, whole-body protein synthesis and oxidation rates increased to a greater extent in lean men than in the obese (P-interaction < 0.05), resulting in a higher whole-body protein net balance in the lean than in the obese (7.1 ± 0.2 and 4.6 ± 0.4 µmol phenylalanine · h−1 · kg−1, respectively; P-interaction < 0.001). Myofibrillar protein synthesis rates increased from 0.030 ± 0.002 and 0.028 ± 0.003%/h in the postabsorptive period to 0.034 ± 0.002 and 0.035 ± 0.003%.h−1 in the 5-h postprandial period (P = 0.03) in lean and obese men, respectively, with no differences between groups (P-interaction = 0.58). Conclusions Basal, postabsorptive myofibrillar protein synthesis rates do not differ between lean and obese middle-aged men. Postprandial protein handling, including protein digestion and amino acid absorption, and the postprandial muscle protein synthetic response after the ingestion of 25 g whey protein are not impaired in obese men. This trial was registered at www.trialregister.nl as NTR4060.


2018 ◽  
Vol 58 (2) ◽  
pp. 583-595 ◽  
Author(s):  
Søren Reitelseder ◽  
Kasper Dideriksen ◽  
Jakob Agergaard ◽  
Nikolaj M. Malmgaard-Clausen ◽  
Rasmus L. Bechshoeft ◽  
...  

2019 ◽  
Vol 317 (3) ◽  
pp. E473-E482 ◽  
Author(s):  
Andrew M. Holwerda ◽  
Kevin J. M. Paulussen ◽  
Maarten Overkamp ◽  
Joy P. B. Goessens ◽  
Irene-Fleur Kramer ◽  
...  

Older adults have shown an attenuated postexercise increase in muscle protein synthesis rates following ingestion of smaller amounts of protein compared with younger adults. Consequently, it has been suggested that older adults require the ingestion of more protein to increase postexercise muscle protein synthesis rates compared with younger adults. We investigated whether coingestion of 1.5 g of free leucine with a single 15-g bolus of protein further augments the postprandial muscle protein synthetic response during recovery from resistance-type exercise in older men. Twenty-four healthy older men (67 ± 1 yr) were randomly assigned to ingest 15 g of milk protein concentrate (MPC80) with (15G+LEU; n = 12) or without (15G; n = 12) 1.5 g of free leucine after performing a single bout of resistance-type exercise. Postprandial protein digestion and amino acid absorption kinetics, whole body protein metabolism, and postprandial myofibrillar protein synthesis rates were assessed using primed, continuous infusions with l-[ ring-2H5]phenylalanine, l-[ ring-2H2]tyrosine, and l-[1-13C]leucine combined with ingestion of intrinsically l-[1-13C]phenylalanine-labeled milk protein. A total of 70 ± 1% (10.5 ±0.2 g) and 75 ± 2% (11.2 ± 0.3 g) of the protein-derived amino acids were released in the circulation during the 6-h postexercise recovery phase in 15G+LEU and 15G, respectively ( P < 0.05). Postexercise myofibrillar protein synthesis rates were 16% (0.058 ± 0.003 vs. 0.049 ± 0.002%/h, P < 0.05; based on l-[ ring-2H5]phenylalanine) and 19% (0.071 ± 0.003 vs. 0.060 ± 0.003%/h, P < 0.05; based on l-[1-13C]leucine) greater in 15G+LEU compared with 15G. Leucine coingestion further augments the postexercise muscle protein synthetic response to the ingestion of a single 15-g bolus of protein in older men.


2011 ◽  
Vol 141 (4) ◽  
pp. 568-573 ◽  
Author(s):  
Nicholas A. Burd ◽  
Daniel W. D. West ◽  
Daniel R. Moore ◽  
Philip J. Atherton ◽  
Aaron W. Staples ◽  
...  

Author(s):  
Melynda S. Coker ◽  
Kaylee R. Ladd ◽  
Scott E. Schutzler ◽  
Sanghee Park ◽  
Rick H. Williams ◽  
...  

Wild game consumption has been associated with health benefits, but the influence on protein metabolism remains unknown. We compared the feeding-induced response to 2 oz of free-range reindeer (FR) versus commercial beef (CB) using stable isotope methodology. Seven male and female participants (age: 38&plusmn;12 years; body mass index: 24&plusmn;3 kg/m2) completed two studies using a randomized, crossover design in which they ingested 2 oz of FR or CB. L-[ring 2H5]phenylalanine &amp; L-[ring 2H2]tyrosine were delivered via primed, continuous intravenous infusion. Blood samples were collected during the basal period and following consumption of FR or CB. Feeding-induced changes in whole body protein synthesis (PS), protein breakdown (PB), and net protein balance (NB) were determined via analysis of plasma samples for phenyalanine and tyrosine enrichment by gas chromatography mass spectrometry; plasma essential amino acid concentrations were determined by liquid chromatography-electrospray ionization-mass spectrometry. Plasma post-prandial essential amino acid (EAA) concentrations were higher with the ingestion of FR compared to CB (P=0.02). The acute feeding-induced response in PS was not different in either trial, but PB was reduced with the ingestion of FR compared to CB (P&lt;0.0001). The difference in PB contributed to a superior level of NB (P&lt;0.0001). When protein kinetics were normalized relative to the amino acids ingested, PB/EAAs and total amino acids ingested were reduced (P&lt;0.01 and 0.001, respectively) in FR compared to CB; contributing to greater NB/total amino acid ingested (P&lt;0.0001) between FR and CB. We conclude that the nutrient profiles of FR may have a more favorable benefit on protein metabolism compared to CB. These data support the potential health benefits of wild game in the preservation of whole-body protein.


2011 ◽  
Vol 300 (1) ◽  
pp. E231-E242 ◽  
Author(s):  
Søren Reitelseder ◽  
Jakob Agergaard ◽  
Simon Doessing ◽  
Ida C. Helmark ◽  
Peter Lund ◽  
...  

Muscle protein turnover following resistance exercise and amino acid availability are relatively well described. By contrast, the beneficial effects of different sources of intact proteins in relation to exercise need further investigation. Our objective was to compare muscle anabolic responses to a single bolus intake of whey or casein after performance of heavy resistance exercise. Young male individuals were randomly assigned to participate in two protein trials ( n = 9) or one control trial ( n = 8). Infusion of l-[1-13C]leucine was carried out, and either whey, casein (0.3 g/kg lean body mass), or a noncaloric control drink was ingested immediately after exercise. l-[1-13C]leucine-labeled whey and casein were used while muscle protein synthesis (MPS) was assessed. Blood and muscle tissue samples were collected to measure systemic hormone and amino acid concentrations, tracer enrichments, and myofibrillar protein synthesis. Western blots were used to investigate the Akt signaling pathway. Plasma insulin and branched-chain amino acid concentrations increased to a greater extent after ingestion of whey compared with casein. Myofibrillar protein synthesis was equally increased 1–6 h postexercise after whey and casein intake, both of which were higher compared with control ( P < 0.05). Phosphorylation of Akt and p70S6K was increased after exercise and protein intake ( P < 0.05), but no differences were observed between the types of protein except for total 4E-BP1, which was higher after whey intake than after casein intake ( P < 0.05). In conclusion, whey and casein intake immediately after resistance exercise results in an overall equal MPS response despite temporal differences in insulin and amino acid concentrations and 4E-BP1.


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