title: Exercise Tolerance Can Be Enhanced through a Change in Work Rate within the Severe Intensity Domain: Work above Critical Power Is Not Constant.
abstract: BACKGROUND
  The characterization of the hyperbolic power-time (P-tlim) relationship using a two-parameter model implies that exercise tolerance above the asymptote (Critical Power; CP), i.e. within the severe intensity domain, is determined by the curvature (W') of the relationship.
  
  
  OBJECTIVE
  The purposes of this study were (1) to test whether the amount of work above CP (W>CP) remains constant for varied work rate experiments of high volatility change and (2) to ascertain whether W' determines exercise tolerance within the severe intensity domain.
  
  
  METHODS
  Following estimation of CP (208 ± 19 W) and W' (21.4 ± 4.2 kJ), 14 male participants (age: 26 ± 3; peak VO2: 3708 ± 389 ml.min(-1)) performed two experimental trials where the work rate was initially set to exhaust 70% of W' in 3 ('THREE') or 10 minutes ('TEN') before being subsequently dropped to CP plus 10 W.
  
  
  RESULTS
  W>CP for TEN (104 ± 22% W') and W' were not significantly different (P>0.05) but lower than W>CP for THREE (119 ± 17% W', P<0.05). For both THREE (r = 0.71, P<0.01) and TEN (r = 0.64, P<0.01), a significant bivariate correlation was found between W' and tlim.
  
  
  CONCLUSIONS
  W>CP and tlim can be greater than predicted by the P-tlim relationship when a decrement in the work rate of high-volatility is applied. Exercise tolerance can be enhanced through a change in work rate within the severe intensity domain. W>CP is not constant.
authors.affiliation: Centre for Sport and Exercise Science and Medicine, University of Brighton, Eastbourne, United Kingdom.
authors.forename: Jeanne
authors.initials: J
authors.lastname: Dekerle
authors.affiliation: Physical Effort Laboratory, Sports Center, Federal University of Santa Catarina, Florianópolis, Brazil.
authors.forename: Kristopher Mendes
authors.initials: KM
authors.lastname: de Souza
authors.affiliation: Physical Effort Laboratory, Sports Center, Federal University of Santa Catarina, Florianópolis, Brazil.
authors.forename: Ricardo Dantas
authors.initials: RD
authors.lastname: de Lucas
authors.affiliation: Physical Effort Laboratory, Sports Center, Federal University of Santa Catarina, Florianópolis, Brazil.
authors.forename: Luiz Guilherme Antonacci
authors.initials: LG
authors.lastname: Guglielmo
authors.affiliation: UNESP, Human Performance Laboratory, Rio Claro, Brazil.
authors.forename: Camila Coelho
authors.initials: CC
authors.lastname: Greco
authors.affiliation: UNESP, Human Performance Laboratory, Rio Claro, Brazil.
authors.forename: Benedito Sérgio
authors.initials: BS
authors.lastname: Denadai
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000328:Adult; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods*; D017079:Exercise Tolerance / Q000502:physiology*; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology*; D055815:Young Adult