title: Acute Responses to High-Intensity Intermittent Exercise in CHD Patients.
abstract: OBJECTIVE
  although the acute physiological responses to continuous exercise have been well documented in CHD patients, no previous study has examined the responses to high-intensity intermittent exercise in these patients. The purpose of this study was to compare the physiological responses to a high-intensity interval exercise (HIIE) protocol versus a moderate-intensity continuous exercise (MICE) protocol of similar energy expenditure in CHD patients.
  
  
  METHODS
  twenty patients with stable CHD (19 males and 1 female, 62 ± 11 yr) were assigned in random order to a single session of HIIE corresponding to 15-s intervals at 100% of peak power output (PPO) and 15-s passive recovery intervals and, 2 wk later, to an isocaloric MICE corresponding to 70% of PPO.
  
  
  RESULTS
  both protocols were equivalent in terms of energy expenditure. The HIIE protocol resulted in lower mean ventilation (P < 0.001) for a small difference in metabolic demand. All participants preferred the HIIE mainly because the perceived exertion measured by the Borg scale was lower (P < 0.05). No elevation of serum concentration of troponin T was found in all participants at baseline and at 20 min and 24 h after the exercise sessions, thus excluding the presence of any exercise-induced myocardial injury in our patients.
  
  
  CONCLUSIONS
  when considering physiological responses, safety, and perceived exertion, the HIIE protocol seemed to be well tolerated and more efficient in this group of stable CHD patients.
authors.affiliation: Montreal Heart Institute, Cardiovascular Prevention Centre (Centre ÉPIC), University de Montreal, Montreal, CANADA.
authors.forename: Thibaut
authors.initials: T
authors.lastname: Guiraud
authors.forename: Anil
authors.initials: A
authors.lastname: Nigam
authors.forename: Martin
authors.initials: M
authors.lastname: Juneau
authors.forename: Philippe
authors.initials: P
authors.lastname: Meyer
authors.forename: Mathieu
authors.initials: M
authors.lastname: Gayda
authors.forename: Laurent
authors.initials: L
authors.lastname: Bosquet
mesh_terms: D000368:Aged; D003327:Coronary Disease / Q000628:therapy*; D004734:Energy Metabolism / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D020107:Troponin T / Q000097:blood
chemical_list: D020107:Troponin T