Relationship between %HRmax, %HR Reserve, %VO sub(2max), and %VO sub(2) Reserve in Elite Cyclists

• Published in: Medicine and science in sports and exercise 2007-02, Vol.39 (2), p.350-357
• Main Authors: Lounana, J, Campion, F, Noakes, T D, Medelli, J
• Format: Article
• Language: English
• ISSN: 0195-9131
• DOI: 10.1249/01.mss.0000246996.63976.5f

Purpose: To evaluate the relations between %HRmax, %HRR, %VO sub(2max), and %VO sub(2)R 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 plus or minus 0.7 yr, 71.0 plus or minus 1.2 kg, 70.9 plus or minus 1.2 mL times kg super(-1) times min super(-1), 433.9 plus or minus 9.8 W) performed an incremental maximal exercise test (50 W times 3 min super(-1)). Individual linear regressions based on HR and VO sub(2) values measured at rest, end of each stage, and maximum, were used to calculate slopes and intercepts, and to predict %HRmax, %HRR, %VO sub(2max), or %VO sub(2)R for a given exercise intensity. Results: Below 85% VO sub(2max) or VO sub(2)R, 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% VO sub(2max), and 48, 61, 74% vs 35, 55, and 70% HRmax at 20, 40, and 60% VO sub(2)R). The %HRR versus %VO sub(2max) regression mean slope (1.069 plus or minus 0.01) and intercept (-5.747 plus or minus 0.80) were significantly different (P < 0.0001) from 1 and 0, respectively. Conversely, the %HRR versus %VO sub(2)R regression was indistinguishable from the line of identity (mean slope = 1.003 plus or minus 0.01; mean intercept = 0.756 plus or minus 0.7). Predicted %VO sub(2)R values were equivalent to %HRR in the 35-95%HRR range. %VO sub(2max) 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). Conclusion: The intensity scale recommended by ACSM underestimates exercise intensity in elite cyclists. Prediction of %HRR by %VO sub(2)R is better than by %VO sub(2max). Thus, elite cyclists should use %HRR in relation to %VO sub(2)R rather than in relation to %VO sub(2max).