title: The limit to exercise tolerance in humans: mind over muscle?
abstract: In exercise physiology, it has been traditionally assumed that high-intensity aerobic exercise stops at the point commonly called exhaustion because fatigued subjects are no longer able to generate the power output required by the task despite their maximal voluntary effort. We tested the validity of this assumption by measuring maximal voluntary cycling power before (mean +/- SD, 1,075 +/- 214 W) and immediately after (731 +/- 206 W) (P < 0.001) exhaustive cycling exercise at 242 +/- 24 W (80% of peak aerobic power measured during a preliminary incremental exercise test) in ten fit male human subjects. Perceived exertion during exhaustive cycling exercise was strongly correlated (r = -0.82, P = 0.003) with time to exhaustion (10.5 +/- 2.1 min). These results challenge the long-standing assumption that muscle fatigue causes exhaustion during high-intensity aerobic exercise, and suggest that exercise tolerance in highly motivated subjects is ultimately limited by perception of effort.
authors.affiliation: School of Sport, Health and Exercise Sciences, Bangor University, Normal Site, Holyhead Road, Bangor, Gwynedd LL57 2PZ, Wales, UK. s.m.marcora@bangor.ac.uk
authors.forename: Samuele Maria
authors.initials: SM
authors.lastname: Marcora
authors.forename: Walter
authors.initials: W
authors.lastname: Staiano
mesh_terms: D001642:Bicycling; D015444:Exercise / Q000523:psychology*; D017079:Exercise Tolerance; D006339:Heart Rate; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008960:Models, Psychological; D009042:Motivation; D009119:Muscle Contraction; D018763:Muscle Fatigue; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000502:physiology*; D010101:Oxygen Consumption; D010465:Perception; D015203:Reproducibility of Results; D013997:Time Factors; D055815:Young Adult
chemical_list: D019344:Lactic Acid