title: Effect of eccentric exercise with reduced muscle glycogen on plasma interleukin-6 and neuromuscular responses of musculus quadriceps femoris.
abstract: Eccentric exercise can result in muscle damage and interleukin-6 (IL-6) secretion. Glycogen availability is a potent stimulator of IL-6 secretion. We examined effects of eccentric exercise in a low-glycogen state on neuromuscular function and plasma IL-6 secretion. Twelve active men (23 ± 4 yr, 179 ± 5 cm, 77 ± 10 kg, means ± SD) completed two downhill treadmill runs (gradient, -12%, 5 × 8 min; speed, 12.1 ± 1.1 km/h) with normal (NG) and reduced muscle glycogen (RG) in randomized order and at least 6 wk apart. Muscle glycogen was reduced using an established cycling protocol until exhaustion and dietary manipulation the evening before the morning run. Physiological responses were measured up to 48 h after the downhill runs. During recovery, force deficits of musculus quadriceps femoris by maximal isometric contractions were similar. Changes in low-frequency fatigue were larger with RG. Voluntary activation and plasma IL-6 levels were similar in recovery between conditions. It is concluded that unaccustomed, damaging eccentric exercise with low muscle glycogen of the m. quadriceps femoris 1) exacerbated low-frequency fatigue but 2) had no additional effect on IL-6 secretion. Neuromuscular impairment after eccentric exercise with low muscle glycogen appears to have a greater peripheral component in early recovery.
authors.affiliation: Department of Sport and Exercise Sciences, University of Chichester, Chichester, United Kingdom.
authors.forename: James P
authors.initials: JP
authors.lastname: Gavin
authors.affiliation: Department of Sport and Exercise Sciences, University of Chichester, Chichester, United Kingdom.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Myers
authors.affiliation: Department of Sport and Exercise Sciences, University of Chichester, Chichester, United Kingdom m.willems@chi.ac.uk.
authors.forename: Mark E T
authors.initials: ME
authors.lastname: Willems
mesh_terms: D000328:Adult; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods; D005221:Fatigue / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism*; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism*; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D052097:Quadriceps Muscle / Q000378:metabolism* / Q000502:physiology*; D012420:Running / Q000502:physiology; D055815:Young Adult
chemical_list: D015850:Interleukin-6; D006003:Glycogen
keywords: eccentric exercise; keyword: interleukin-6; muscle glycogen