title: Myogenic response of human skeletal muscle to 12 weeks of resistance training at light loading intensity.
abstract: There is strong evidence for enhanced numbers of satellite cells with heavy resistance training. The satellite cell response to very light muscle loading is, however, unknown. We, therefore, designed a 12-week training protocol where volunteers trained one leg with a high load (H) and the other leg with a light load (L). Twelve young healthy men [mean age 25 ± 3 standard deviation (SD) years] volunteered for the study. Muscle biopsies were collected from the m. vastus lateralis of both legs before and after the training period and satellite cells were visualized by CD56 immunohistochemistry. A significant main effect of time was observed (P<0.001) for the number of CD56+ cells per fiber (L: from 0.11 ± 0.02 to 0.13 ± 0.03; H: from 0.12 ± 0.03 to 0.15 ± 0.05, mean ± SD). The finding that 12 weeks of training skeletal muscle even with very light loads can induce an increase in the number of satellite cells reveals a new aspect of myogenic precursor cell activation and suggests that satellite cells may play a role in skeletal muscle adaptation over a broad physiological range.
authors.affiliation: Department of Orthopaedic Surgery M, Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark. abigail.mackey@gmail.com
authors.forename: A L
authors.initials: AL
authors.lastname: Mackey
authors.forename: L
authors.initials: L
authors.lastname: Holm
authors.forename: S
authors.initials: S
authors.lastname: Reitelseder
authors.forename: T G
authors.initials: TG
authors.lastname: Pedersen
authors.forename: S
authors.initials: S
authors.lastname: Doessing
authors.forename: F
authors.initials: F
authors.lastname: Kadi
authors.forename: M
authors.initials: M
authors.lastname: Kjaer
mesh_terms: D000328:Adult; D001706:Biopsy; D019002:CD56 Antigen / Q000032:analysis / Q000378:metabolism; D003718:Denmark; D006801:Humans; D008297:Male; D024510:Muscle Development / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D052097:Quadriceps Muscle / Q000254:growth & development* / Q000378:metabolism / Q000502:physiology; D055070:Resistance Training; D032496:Satellite Cells, Skeletal Muscle / Q000378:metabolism*; D055815:Young Adult
chemical_list: D019002:CD56 Antigen