Failed Recovery of Glycemic Control and Myofibrillar Protein Synthesis With 2 wk of Physical Inactivity in Overweight, Prediabetic Older Adults

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.

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Aerobic Exercise Training Improves Myofibrillar Protein Synthesis, Capillarization, and Quadriceps Strength in Older Adults

Medicine & Science in Sports & Exercise ◽

10.1249/01.mss.0000537222.24538.0d ◽

2018 ◽

Vol 50 (5S) ◽

pp. 646

Author(s):

Camille R. Brightwell ◽

Tatiana Moro ◽

Christopher S. Fry ◽

Melissa M. Markofski ◽

Elena Volpi ◽

...

Keyword(s):

Older Adults ◽

Protein Synthesis ◽

Exercise Training ◽

Aerobic Exercise ◽

Quadriceps Strength ◽

Myofibrillar Protein ◽

Aerobic Exercise Training ◽

Myofibrillar Protein Synthesis

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A mycoprotein-based high-protein vegan diet supports equivalent daily myofibrillar protein synthesis rates compared with an isonitrogenous omnivorous diet in older adults: a randomised controlled trial

British Journal Of Nutrition ◽

10.1017/s0007114520004481 ◽

2020 ◽

pp. 1-11

Author(s):

Alistair J. Monteyne ◽

Mandy V. Dunlop ◽

David J. Machin ◽

Mariana O. C. Coelho ◽

George F. Pavis ◽

...

Keyword(s):

Older Adults ◽

Protein Synthesis ◽

Controlled Trial ◽

Control Period ◽

Myofibrillar Protein ◽

High Protein ◽

Dietary Control ◽

Deuterated Water ◽

Healthy Older Adults ◽

Myofibrillar Protein Synthesis

Abstract Animal-derived dietary protein ingestion and physical activity stimulate myofibrillar protein synthesis rates in older adults. We determined whether a non-animal-derived diet can support daily myofibrillar protein synthesis rates to the same extent as an omnivorous diet. Nineteen healthy older adults (aged 66 (sem 1) years; BMI 24 (sem 1) kg/m2; twelve males, seven females) participated in a randomised, parallel-group, controlled trial during which they consumed a 3-d isoenergetic high-protein (1·8 g/kg body mass per d) diet, where the protein was provided from predominantly (71 %) animal (OMNI; n 9; six males, three females) or exclusively vegan (VEG; n 10; six males, four females; mycoprotein providing 57 % of daily protein intake) sources. During the dietary control period, participants conducted a daily bout of unilateral resistance-type leg extension exercise. Before the dietary control period, participants ingested 400 ml of deuterated water, with 50-ml doses consumed daily thereafter. Saliva samples were collected throughout to determine body water 2H enrichments, and muscle samples were collected from rested and exercised muscle to determine daily myofibrillar protein synthesis rates. Deuterated water dosing resulted in body water 2H enrichments of approximately 0·78 (sem 0·03) %. Daily myofibrillar protein synthesis rates were 13 (sem 8) (P = 0·169) and 12 (sem 4) % (P = 0·016) greater in the exercised compared with rested leg (1·59 (sem 0·12) v. 1·77 (sem 0·12) and 1·76 (sem 0·14) v. 1·93 (sem 0·12) %/d) in OMNI and VEG groups, respectively. Daily myofibrillar protein synthesis rates did not differ between OMNI and VEG in either rested or exercised muscle (P > 0·05). Over the course of a 3-d intervention, omnivorous- or vegan-derived dietary protein sources can support equivalent rested and exercised daily myofibrillar protein synthesis rates in healthy older adults consuming a high-protein diet.

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No independent or combined effects of vitamin D and conjugated linoleic acids on muscle protein synthesis in older adults: a randomized, double-blind, placebo-controlled clinical trial

American Journal of Clinical Nutrition ◽

10.1093/ajcn/nqaa240 ◽

2020 ◽

Vol 112 (5) ◽

pp. 1382-1389

Author(s):

Stephan van Vliet ◽

Alan Fappi ◽

Dominic N Reeds ◽

Bettina Mittendorfer

Keyword(s):

Older Adults ◽

Vitamin D ◽

Protein Synthesis ◽

Muscle Protein ◽

Muscle Protein Synthesis ◽

Myofibrillar Protein ◽

Controlled Clinical Trial ◽

Double Blind ◽

Before And After ◽

Myofibrillar Protein Synthesis

ABSTRACT Background Aging is associated with skeletal muscle anabolic resistance (i.e., reduced muscle protein synthesis during anabolic conditions such as hyperaminoacidemia). The results from studies conducted in cell culture systems and animals suggest that both vitamin D and conjugated linoleic acids (CLAs) stimulate muscle protein synthesis. Objectives To conduct a randomized, double-blind, placebo-controlled clinical trial to determine the independent and combined effects of dietary vitamin D and CLA supplementation on myofibrillar protein synthesis rates in sedentary older adults. Methods Thirty-two sedentary, older adults were randomized to receive either: 1) 2000 IU vitamin D-3 (Vit D) per day; 2) 4000 mg CLA per day; 3) both Vit D (2000 IU/d) and CLA (4000 mg/d); or 4) placebo for 8 wk. Myofibrillar protein synthesis rates were evaluated by using intravenous [ring-2H5]phenylalanine infusion in conjunction with muscle biopsies during basal, postabsorptive conditions and during combined amino acid and insulin infusion before and after the supplementation period. Results Before the intervention, basal myofibrillar protein synthesis rates were not different among groups (Placebo: 0.033 ± 0.003; Vit D: 0.034 ± 0.002; CLA: 0.029 ± 0.005; Vit D + CLA: 0.038 ± 0.005 %·h-1), and hyperinsulinemia–hyperaminoacidemia increased myofibrillar protein synthesis rates by ∼35%. Compared with placebo, neither Vit D nor CLA nor combined Vit D + CLA supplementation affected the basal myofibrillar protein synthesis rates (placebo: 0.040 ± 0.004%/h; Vit D: 0.044 ± 0.006%/h; CLA: 0.039 ± 0.006%/h; Vit D + CLA: 0.040 ± 0.007%/h) or the hyperinsulinemia–hyperaminoacidemia–induced increase in myofibrillar protein synthesis (percentage increase from basal before and after the interventions: placebo, 30 ± 11 and 36 ± 11; Vit D, 38 ± 8 and 34 ± 10; CLA, 50 ± 14 and 51 ± 16; Vit D + CLA, 29 ± 15 and 35 ± 8). Conclusions Vitamin D and/or CLA supplementation, at the doses provided in our study, does not have muscle anabolic effects in sedentary older adults. The study was registered at clinicaltrials.gov (NCT03115775).

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Presleep dietary protein-derived amino acids are incorporated in myofibrillar protein during postexercise overnight recovery

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00273.2016 ◽

2018 ◽

Vol 314 (5) ◽

pp. E457-E467 ◽

Cited By ~ 33

Author(s):

Jorn Trommelen ◽

Imre W. K. Kouw ◽

Andrew M. Holwerda ◽

Tim Snijders ◽

Shona L. Halson ◽

...

Keyword(s):

Amino Acids ◽

Protein Synthesis ◽

Dietary Protein ◽

Myofibrillar Protein ◽

Whole Body ◽

Body Protein ◽

Protein Ingestion ◽

Casein Protein ◽

The Impact ◽

Myofibrillar Protein Synthesis

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.

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Hypoenergetic diet-induced reductions in myofibrillar protein synthesis are restored with resistance training and balanced daily protein ingestion in older men

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00550.2014 ◽

2015 ◽

Vol 308 (9) ◽

pp. E734-E743 ◽

Cited By ~ 58

Author(s):

Caoileann H. Murphy ◽

Tyler A. Churchward-Venne ◽

Cameron J. Mitchell ◽

Nathan M. Kolar ◽

Amira Kassis ◽

...

Keyword(s):

Protein Synthesis ◽

Resistance Training ◽

Older Men ◽

Myofibrillar Protein ◽

Energy Restriction ◽

Protein Distribution ◽

Protein Meal ◽

Fed State ◽

Sarcoplasmic Protein ◽

Myofibrillar Protein Synthesis

Strategies to enhance weight loss with a high fat-to-lean ratio in overweight/obese older adults are important since lean loss could exacerbate sarcopenia. We examined how dietary protein distribution affected muscle protein synthesis during energy balance (EB), energy restriction (ER), and energy restriction plus resistance training (ER + RT). A 4-wk ER diet was provided to overweight/obese older men (66 ± 4 yr, 31 ± 5 kg/m2) who were randomized to either a balanced (BAL: 25% daily protein/meal × 4) or skewed (SKEW: 7:17:72:4% daily protein/meal; n = 10/group) pattern. Myofibrillar and sarcoplasmic protein fractional synthetic rates (FSR) were measured during a 13-h primed continuous infusion of l-[ ring-13C6]phenylalanine with BAL and SKEW pattern of protein intake in EB, after 2 wk ER, and after 2 wk ER + RT. Fed-state myofibrillar FSR was lower in ER than EB in both groups ( P < 0.001), but was greater in BAL than SKEW ( P = 0.014). In ER + RT, fed-state myofibrillar FSR increased above ER in both groups and in BAL was not different from EB ( P = 0.903). In SKEW myofibrillar FSR remained lower than EB ( P = 0.002) and lower than BAL ( P = 0.006). Fed-state sarcoplasmic protein FSR was reduced similarly in ER and ER + RT compared with EB ( P < 0.01) in both groups. During ER in overweight/obese older men a BAL consumption of protein stimulated the synthesis of muscle contractile proteins more effectively than traditional, SKEW distribution. Combining RT with a BAL protein distribution “rescued” the lower rates of myofibrillar protein synthesis during moderate ER.

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Rapid aminoacidemia enhances myofibrillar protein synthesis and anabolic intramuscular signaling responses after resistance exercise

American Journal of Clinical Nutrition ◽

10.3945/ajcn.111.013722 ◽

2011 ◽

Vol 94 (3) ◽

pp. 795-803 ◽

Cited By ~ 154

Author(s):

D. W. West ◽

N. A. Burd ◽

V. G. Coffey ◽

S. K. Baker ◽

L. M. Burke ◽

...

Keyword(s):

Protein Synthesis ◽

Resistance Exercise ◽

Myofibrillar Protein ◽

Myofibrillar Protein Synthesis

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Impact of Short-term Sedentariness on Week-to-Week Myofibrillar Protein Synthesis Rates in Physically Active Young Men

Medicine & Science in Sports & Exercise ◽

10.1249/01.mss.0000536301.79919.83 ◽

2018 ◽

Vol 50 (5S) ◽

pp. 370

Author(s):

Brandon J. Shad ◽

Andrew M. Holwerda ◽

Yasir S. Elhassan ◽

Luc J.C. van Loon ◽

Janice L. Thompson ◽

...

Keyword(s):

Protein Synthesis ◽

Young Men ◽

Myofibrillar Protein ◽

Short Term ◽

Physically Active ◽

Myofibrillar Protein Synthesis

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Improved recovery from skeletal muscle damage is largely unexplained by myofibrillar protein synthesis or inflammatory and regenerative gene expression pathways

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00454.2020 ◽

2020 ◽

Author(s):

George Frederick Pavis ◽

Tom SO Jameson ◽

Marlou L. Dirks ◽

Benjamin P. Lee ◽

Doaa Reda Abdelrahman ◽

...

Keyword(s):

Skeletal Muscle ◽

Protein Synthesis ◽

Muscle Damage ◽

Muscle Function ◽

Nutritional Intervention ◽

Myofibrillar Protein ◽

Skeletal Muscle Damage ◽

Amino Acid Availability ◽

Expression Pathways ◽

Myofibrillar Protein Synthesis

The contribution of myofibrillar protein synthesis (MyoPS) to recovery from skeletal muscle damage in humans is unknown. Recreationally active males and females consumed a daily protein-polyphenol beverage targeted at increasing amino acid availability and reducing inflammation (PPB; n=9), both known to affect MyoPS, or an isocaloric placebo (PLA; n=9) during 168 h of recovery from 300 maximal unilateral eccentric contractions (EE). Muscle function was assessed daily. Muscle biopsies were collected 24, 27, 36, 72 and 168 h for MyoPS measurements using 2H2O and expression of 224 genes using RT-qPCR and pathway analysis. PPB improved recovery of muscle function, which was impaired for five days following EE in PLA (interaction; P<0.05). Acute postprandial MyoPS rates were unaffected by nutritional intervention (24-27 h). EE increased overnight (27-36 h) MyoPS versus control leg (PLA: 33±19%; PPB: 79±25%; leg P<0.01), and PPB tended to increase this further (interaction P=0.06). Daily MyoPS rates were greater with PPB between 72-168 h after EE, albeit after function had recovered. Inflammatory and regenerative signaling pathways were dramatically upregulated and clustered following EE but were unaffected by nutritional intervention. These results suggest that accelerated recovery from EE is not explained by elevated MyoPS or suppression of inflammation.

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