title: Alterations in Whole-Body Insulin Sensitivity Resulting From Repeated Eccentric Exercise of a Single Muscle Group: A Pilot Investigation.
abstract: Unaccustomed eccentric exercise using large muscle groups elicits soreness, decrements in physical function and impairs markers of whole-body insulin sensitivity; although these effects are attenuated with a repeated exposure. Eccentric exercise of a small muscle group (elbow flexors) displays similar soreness and damage profiles in response to repeated exposure. However, it is unknown whether damage to small muscle groups impacts upon whole-body insulin sensitivity. This pilot investigation aimed to characterize whole-body insulin sensitivity in response to repeated bouts of eccentric exercise of the elbow flexors. Nine healthy males completed two bouts of eccentric exercise separated by 2 weeks. Insulin resistance (updated homeostasis model of insulin resistance, HOMA2-IR) and muscle damage profiles (soreness and physical function) were assessed before, and 48 h after exercise. Matsuda insulin sensitivity indices (ISI Matsuda) were also determined in 6 participants at the same time points as HOMA2-IR. Soreness was elevated, and physical function impaired, by both bouts of exercise (both p < .05) but to a lesser extent following bout 2 (time x bout interaction, p < .05). Eccentric exercise decreased ISI Matsuda after the first but not the second bout of eccentric exercise (time x bout interaction p < .05). Eccentric exercise performed with an isolated upper limb impairs whole-body insulin sensitivity after the first, but not the second, bout.
authors: Dept. of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle-upon-Tyne, UK.
authors: Javier T
authors: JT
authors: Gonzalez
authors: Martin J
authors: MJ
authors: Barwood
authors: Stuart
authors: S
authors: Goodall
authors: Kevin
authors: K
authors: Thomas
authors: Glyn
authors: G
authors: Howatson
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D012090:Cumulative Trauma Disorders / Q000097:blood / Q000209:etiology / Q000378:metabolism* / Q000503:physiopathology; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism / Q000517:prevention & control*; D004550:Elbow; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D009119:Muscle Contraction; D053581:Muscle Strength Dynamometer; D018482:Muscle, Skeletal / Q000502:physiology* / Q000503:physiopathology; D063806:Myalgia / Q000209:etiology*; D010865:Pilot Projects; D016059:Range of Motion, Articular; D055070:Resistance Training / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin