title: Relationship between %HRmax, %HR reserve, %VO2max, and %VO2 reserve in elite cyclists.
abstract: OBJECTIVE
  To evaluate the relations between %HRmax, %HRR, %VO2max, and %VO2R in elite cyclists and to check whether the intensity scale recommended by ACSM in its 1998 position stand is also applicable to this specific population.
  
  
  METHODS
  Twenty-six male elite road cyclists (25.1 +/- 0.7 yr, 71.0 +/- 1.2 kg, 70.9 +/- 1.2 mL x kg(-1) x min(-1), 433.9 +/- 9.8 W) performed an incremental maximal exercise test (50 W x 3 min(-1)). Individual linear regressions based on HR and VO2 values measured at rest, end of each stage, and maximum, were used to calculate slopes and intercepts, and to predict %HRmax, %HRR, %VO2max, or %VO2R for a given exercise intensity.
  
  
  RESULTS
  Below 85% VO2max or VO2R, predicted %HRmax values were significantly higher (P < 0.001) than the ACSM intensity scale (58, 65, 73, and 87% vs 55, 62, 70, and 85% HRmax at 40, 50, 60, and 80% VO2max, and 48, 61, 74% vs 35, 55, and 70% HRmax at 20, 40, and 60% VO2R). The %HRR versus %VO2max regression mean slope (1.069 +/- 0.01) and intercept (-5.747 +/- 0.80) were significantly different (P < 0.0001) from 1 and 0, respectively. Conversely, the %HRR versus %VO2R regression was indistinguishable from the line of identity (mean slope = 1.003 +/- 0.01; mean intercept = 0.756 +/- 0.7). Predicted %VO2R values were equivalent to %HRR in the 35-95%HRR range. %VO2max was equivalent to %HRR at and above 75%HRR, and it was significantly higher at (P < 0.05) and below 65%HRR (P < 0.001).
  
  
  CONCLUSIONS
  The intensity scale recommended by ACSM underestimates exercise intensity in elite cyclists. Prediction of %HRR by %VO2R is better than by %VO2max. Thus, elite cyclists should use %HRR in relation to %VO2R rather than in relation to %VO2max.
authors.affiliation: Unit for Exercise Biology and Sports Medicine, University Hospital Center, Amiens, France.
authors.forename: Joseph
authors.initials: J
authors.lastname: Lounana
authors.forename: Frederic
authors.initials: F
authors.lastname: Campion
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Noakes
authors.forename: Jean
authors.initials: J
authors.lastname: Medelli
mesh_terms: D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology*; D000886:Anthropometry; D001642:Bicycling / Q000502:physiology*; D015992:Body Mass Index; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007321:Inspiratory Reserve Volume; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology*; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange / Q000502:physiology; D012146:Rest