title: Heart rate and perceived muscle pain responses to a functional walking test in McArdle disease.
abstract: The aim of this study was to assess a 12-min self-paced walking test in patients with McArdle disease. Twenty patients (44.7 ± 11 years; 11 female) performed the walking test where walking speed, distance walked, heart rate (HR) and perceived muscle pain (Borg CR10 scale) were measured. Median (interquartile range) distance walked was 890 m (470-935). From 1 to 6 min, median walking speed decreased (from 75.0 to 71.4 m∙min(-1)) while muscle pain and %HR reserve increased (from 0.3 to 3.0 and 37% to 48%, respectively). From 7 to 12 min, walking speed increased to 74.2 m∙min(-1), muscle pain decreased to 1.6 and %HR reserve remained between 45% and 48%. To make relative comparisons, HR and muscle pain were divided by walking speed and expressed as ratios. These ratios rose significantly between 1 and 6 min (HR:walking speed P = .001 and pain:walking speed P < .001) and similarly decreased between 6 and 11 min (P = .002 and P = .001, respectively). Peak ratios of HR:walking speed and pain:walking speed were inversely correlated to distance walked: rs (HR) = -.82 (P < .0001) and rs (pain) = -.55 (P = .012). Largest peak ratios were found in patients who walked < 650 m. A 12-min walking test can be used to assess exercise capacity and detect the second wind in McArdle disease.
authors.affiliation: a Department of Clinical Sciences and Nutrition , University of Chester , Chester , UK.
authors.forename: John P
authors.initials: JP
authors.lastname: Buckley
authors.forename: Ros M
authors.initials: RM
authors.lastname: Quinlivan
authors.forename: Julius
authors.initials: J
authors.lastname: Sim
authors.forename: Roger G
authors.initials: RG
authors.lastname: Eston
authors.forename: Deborah S
authors.initials: DS
authors.lastname: Short
mesh_terms: D000328:Adult; D003402:Creatine Kinase / Q000097:blood / Q000652:urine; D005080:Exercise Test; D006012:Glycogen Storage Disease Type V / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D063806:Myalgia / Q000503:physiopathology* / Q000523:psychology*; D009211:Myoglobin / Q000097:blood; D009212:Myoglobinuria; D010465:Perception; D016138:Walking / Q000502:physiology*
chemical_list: D009211:Myoglobin; D003402:Creatine Kinase
keywords: 12-min walk test; Borg’s pain scale; second-wind