title: High-intensity interval training improves performance in young and older individuals by increasing mechanical efficiency.
abstract: This study evaluated the effects of 6 weeks of high-intensity interval training (HIIT) on mechanical efficiency (ME) in young and older groups. Seventeen healthy young adults [26.2(2.4) year], and thirteen healthy older adults [54.5(2.3) year] completed a 6-week HIIT intervention (three sessions per week) on an electromagnetically braked cycle ergometer. Each HIIT session contained six repetitions of supramaximal exercise intervals (6 seconds each) with 2 min of passive recovery between each repetition. ME (%) were computed in net terms across stages corresponding to ventilator thresholds 1 (VT1) and 2 (VT2) and at 100% of maximal oxygen consumption (VO2max) of an incremental maximal cycling test. After 6 weeks, the ME values did not differ between the two groups and were significantly higher than the ones at baseline (P<0.01). In this study, the multiple linear regression analysis demonstrated the increases in maximal power (Pmax) contributed significantly to ME increases over 6 weeks at VT1, VT2 and at 100% of VO2maxThis model accounted respectively for 28, 38, and 42%, of the increases. In older adults, ME determined during incremental maximal cycling test increases at VT1, VT2 and at 100% over 6-week HIIT intervention, and the increment appeared to be related to increases in Pmax. HIIT can be recommended as a strategy aimed at improving muscle efficiency among older adults.
authors.affiliation: School of Kinesiology and Leisure, Faculty of Health Sciences and Community Services, Université de Moncton, Moncton, New Brunswick, Canada georgesjabbour1980@hotmail.com.
authors.forename: Georges
authors.initials: G
authors.lastname: Jabbour
authors.affiliation: School of Kinesiology and Leisure, Faculty of Health Sciences and Community Services, Université de Moncton, Moncton, New Brunswick, Canada.
authors.forename: Horia-Daniel
authors.initials: HD
authors.lastname: Iancu
authors.affiliation: Department of Kinesiology, Université Laval, Québec, Canada.
authors.forename: Pascale
authors.initials: P
authors.lastname: Mauriège
authors.affiliation: Department of Kinesiology, Université Laval, Québec, Canada.
authors.forename: Denis R
authors.initials: DR
authors.lastname: Joanisse
authors.affiliation: Department of Biology, Faculty of Sciences, Université de Moncton, Moncton, New Brunswick, Canada.
authors.forename: Luc J
authors.initials: LJ
authors.lastname: Martin
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000502:physiology; D000072696:High-Intensity Interval Training; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology; D055815:Young Adult
keywords: Energy expenditure; mechanical efficiency; power; ratings of perceived‐exertion; ventilator thresholds 1; ventilator thresholds 2