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Satellite Cell Behavior in Cyclists Following Intensified Training With and Without Protein Supplementation
Author(s) -
Luden Nicholas,
McKenzie Alec,
Saunders Michael,
Womack Christopher,
D'Lugos Andrew,
Gworek Keith
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.1240.1
Subject(s) - myosin , medicine , biology , chemistry , endocrinology , microbiology and biotechnology
Our objective was to investigate the satellite cell (SC) response of endurance‐trained cyclists (n=8) to 10 days of intensified cycle training (ICT) and 10 days of subsequent recovery (RVT – reduced volume training), with carbohydrate (CHO) and carbohydrate‐protein (PRO) supplementation. Muscle biopsies were obtained from the vastus lateralis before and after ICT and RVT. Immunofluorescent microscopy was used to analyze SCs and myosin heavy chain (MHC) I and IIa. Data were analyzed using magnitude‐based inferences. MHC I SCs were abundant at baseline (38 ± 20 SCs/100 fibers), decreased ( unclear ) from PRE CHO to ICT CHO , and then likely increased by 60 ± 64% following RVT CHO . No other changes in SC content were observed. Myonuclear content of MHC I fibers most likely increased (16 ± 6%) from baseline to ICT CHO . Likewise, MHC IIa myonuclear content likely increased (14 ± 14%) from PRE CHO to RVT CHO . Though there were no changes in fiber size (cross sectional area) under CHO conditions, ICT with PRO supplementation very likely increased MHC I size (14 ± 8%) and likely increased MHC IIa size (16 ± 19%). Trained endurance cyclists possess a relatively large pool of SCs that appeared to facilitate myonuclear accretion with heavy training under carbohydrate conditions. These data strengthen the growing body of evidence demonstrating the non‐hypertrophic role of SCs in skeletal muscle and the possible benefit of protein supplementation. Support or Funding Information This project was supported by James Madison University's College of Health and Behavioral Studies Faculty Research Grant (N. Luden and A. McKenzie) and the Dairy Research Institute (N. Luden and M. Saunders).