Protein Ingestion before Sleep Increases Muscle Mass and Strength Gains during Prolonged Resistance-Type Exercise Training in Healthy Young Men.
BACKGROUND
It has been demonstrated that protein ingestion before sleep increases muscle protein synthesis rates during overnight recovery from an exercise bout. However, it remains to be established whether dietary protein ingestion before sleep can effectively augment the muscle adaptive response to resistance-type exercise training.


OBJECTIVE
Here we assessed the impact of dietary protein supplementation before sleep on muscle mass and strength gains during resistance-type exercise training.


METHODS
Forty-four young men (22 ± 1 y) were randomly assigned to a progressive, 12-wk resistance exercise training program. One group consumed a protein supplement containing 27.5 g of protein, 15 g of carbohydrate, and 0.1 g of fat every night before sleep. The other group received a noncaloric placebo. Muscle hypertrophy was assessed on a whole-body (dual-energy X-ray absorptiometry), limb (computed tomography scan), and muscle fiber (muscle biopsy specimen) level before and after exercise training. Strength was assessed regularly by 1-repetition maximum strength testing.


RESULTS
Muscle strength increased after resistance exercise training to a significantly greater extent in the protein-supplemented (PRO) group than in the placebo-supplemented (PLA) group (+164 ± 11 kg and +130 ± 9 kg, respectively; P < 0.001). In addition, quadriceps muscle cross-sectional area increased in both groups over time (P < 0.001), with a greater increase in the PRO group than in the PLA group (+8.4 ± 1.1 cm(2) vs. +4.8 ± 0.8 cm(2), respectively; P < 0.05). Both type I and type II muscle fiber size increased after exercise training (P < 0.001), with a greater increase in type II muscle fiber size in the PRO group (+2319 ± 368 μm(2)) than in the PLA group (+1017 ± 353 μm(2); P < 0.05).


CONCLUSIONS
Protein ingestion before sleep represents an effective dietary strategy to augment muscle mass and strength gains during resistance exercise training in young men. This trial was registered at clinicaltrials.gov as NCT02222415.
Department of Human Movement Sciences, Faculty of Health, Medicine, and Life Sciences, School for Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands;
Tim
T
Snijders
Department of Human Movement Sciences, Faculty of Health, Medicine, and Life Sciences, School for Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands;
Peter T
PT
Res
Department of Human Movement Sciences, Faculty of Health, Medicine, and Life Sciences, School for Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands;
Joey S J
JS
Smeets
Department of Human Movement Sciences, Faculty of Health, Medicine, and Life Sciences, School for Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands;
Stephan
S
van Vliet
Department of Human Movement Sciences, Faculty of Health, Medicine, and Life Sciences, School for Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands;
Janneau
J
van Kranenburg
Unit Elite Sports, Dutch Olympic Committee*Dutch Sports Federation, Arnhem, The Netherlands; and.
Kamiel
K
Maase
DSM Biotechnology Center, Department of Applied Biochemistry, Delft, The Netherlands.
Arie K
AK
Kies
Department of Human Movement Sciences, Faculty of Health, Medicine, and Life Sciences, School for Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands;
Lex B
LB
Verdijk
Department of Human Movement Sciences, Faculty of Health, Medicine, and Life Sciences, School for Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands; Department of Human Movement Sciences, Faculty of Health, Medicine, and Life Sciences, School for Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands; L.vanLoon@maastrichtuniversity.nl.
Luc J C
LJ
van Loon
D015502:Absorptiometry, Photon; D001823:Body Composition; D015930:Diet Records; D004044:Dietary Proteins / Q000008:administration & dosage*; D004311:Double-Blind Method; D002149:Energy Intake; D006801:Humans; D008297:Male; D018656:Muscle Fibers, Fast-Twitch / Q000502:physiology*; D053580:Muscle Strength; D009752:Nutritional Status; D052097:Quadriceps Muscle / Q000502:physiology; D055070:Resistance Training; D012890:Sleep / Q000502:physiology*; D055815:Young Adult
D004044:Dietary Proteins
exercise training; fiber size; muscle mass; protein; strength