title: Relation between cycling exercise capacity, fiber-type composition, and lower extremity muscle strength and muscle endurance.
abstract: The aim of the study was to determine the relation between peak oxygen uptake V(O2)peak), peak work rate (WRpeak), fiber-type composition, and lower extremity strength and endurance during a maximal incremental cycle test. Thirty-nine healthy sedentary men, aged 30-46, participated in the study. Subjects performed a maximal incremental cycle test and isokinetic knee extension (KE) and flexion (KF) strength and endurance tests at velocities of 60 and 180° · s(-1). Muscle biopsies were taken from m. vastus lateralis and analyzed for fiber-type composition. A significant correlation existed between KE strength and V(O2)peak and WRpeak. Also, KF endurance correlated significantly to V(O2)peak and WRpeak. The KE endurance correlated significantly to WRpeak (rp = 0.32, p < 0.05) and almost significantly to V(O2)peak (rp = 0.28, p = 0.06). Stepwise multiple regression analyses showed that KE strength, KF endurance, and the percentage of type I fibers could explain up to 40% of the variation in V(O2) and WRpeak. The performance of sedentary subjects in a maximal incremental cycle test is highly affected by knee muscle strength and endurance. Fiber-type composition also contributes but to a smaller extent.
authors.affiliation: Department of Health Sciences, Division of Physiotherapy, Lund University, Lund, Sweden. asa.segerstrom@med.lu.se
authors.forename: Asa B
authors.initials: AB
authors.lastname: Segerström
authors.forename: Anna M
authors.initials: AM
authors.lastname: Holmbäck
authors.forename: Ola
authors.initials: O
authors.lastname: Hansson
authors.forename: Targ
authors.initials: T
authors.lastname: Elgzyri
authors.forename: Karl-Fredrik
authors.initials: KF
authors.lastname: Eriksson
authors.forename: Karin
authors.initials: K
authors.lastname: Ringsberg
authors.forename: Leif
authors.initials: L
authors.lastname: Groop
authors.forename: Per
authors.initials: P
authors.lastname: Wollmer
authors.forename: Ola
authors.initials: O
authors.lastname: Thorsson
mesh_terms: D000328:Adult; D005080:Exercise Test; D006801:Humans; D007717:Knee / Q000502:physiology; D035002:Lower Extremity / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology; D018485:Muscle Fibers, Skeletal / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology*