Contraction mode and whey protein intake affect the synthesis rate of intramuscular connective tissue.
In this study we investigated the impact of whey protein hydrolysate and maltodextrin (WPH) intake on intramuscular connective tissue (IMCT) protein fractional synthesis rate (FSR) after maximal shortening and lengthening contractions.



Twenty young men were randomized to receive either WPH or maltodextrin [carbohydrate (CHO)] immediately after completion of unilateral shortening and lengthening knee extensions. Ring-13C6-phenylalanine was infused, and muscle biopsies were obtained. IMCT protein FSR was measured at 1-5, as well as 1-3 and 3-5 hours after contractions and nutrient intake.



During the 1-3-hour recovery, lengthening contractions resulted in a higher FSR than shortening contractions (P < 0.01), independent of supplementation type and, during the 3-5-hour recovery, WPH had a higher FSR than CHO (P < 0.05), independent of prior contraction mode.



The later appearance of a stimulating effect of WPH on the IMCT FSR after strenuous muscle contractions lends support to its ability to promote recovery of the muscle connective tissue matrix after exercise. Muscle Nerve 55: 128-130, 2017.
Institute of Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital, Copenhagen, Denmark.|Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
Lars
L
Holm
Section for Sport Science, Department of Public Health, Aarhus University, Aarhus, Denmark.
Stine Klejs
SK
Rahbek
Section for Sport Science, Department of Public Health, Aarhus University, Aarhus, Denmark.
Jean
J
Farup
Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark.|Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark.
Mikkel Holm
MH
Vendelbo
Section for Sport Science, Department of Public Health, Aarhus University, Aarhus, Denmark.
Kristian
K
Vissing
D000328:Adult; D000704:Analysis of Variance; D003238:Connective Tissue / Q000187:drug effects* / Q000378:metabolism*; D007839:Functional Laterality; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000166:cytology*; D010649:Phenylalanine; D011134:Polysaccharides / Q000494:pharmacology*; D000067816:Whey Proteins / Q000096:biosynthesis* / Q000378:metabolism; D055815:Young Adult
D009124:Muscle Proteins; D011134:Polysaccharides; D000067816:Whey Proteins; D010649:Phenylalanine; C008315:maltodextrin
concentric contraction; eccentric contraction; fractional synthesis rate; milk protein; muscle collagen; resistance exercise