The relationship between %HRpeak %VO2peak in patients with chronic obstructive pulmonary disease

Purpose: The relationship between the percent peak oxygen consumption (%VO2 peak) and percent peak heart rate (%(HRpeak)) has been suggested as a metho d for exercise prescription. According to the American College of Sports Me dicine (ACSM), 50, 60, 80, and 85% of VO2peak represent 62, 70, 85, and 90% of HRpeak respectively. Recent research with young healthy adults has show n that this relationship is not as ACSM suggests. Furthermore, it has been suggested that this relationship be examined in populations with low functi onal capacity. Methods: The present study evaluated the relationship betwee n %HRpeak and %VO2peak in 125 patients with chronic obstructive pulmonary d isease before and then after 3 months of exercise intervention. Results: Th e mean percentages of HRpeak for the COPD patients at baseline were 70, 76, 87, and 90% at 50, 60, 80, and 85% of VO2peak. Percentages of HRpeak, at 5 0, 60, and 80% of VO2peak were significantly different from those suggested by ACSM. The mean percentages of HRpeak after the 3-month exercise interve ntion were 71, 77, 87, and 90% at 50, 60, 80, and 85% of VO2peak. Percentag es of HRpeak, at 50, 60, and 80% of VO2peak were significantly different fr om those suggested by ACSM. There were no significant differences between t he slopes and the intercepts of the two equations used to describe the rela tionship between %HRpeak and %VO2peak. Therefore, we pooled the data from t he pre- and post-intervention tests to form the following equation to descr ibe the relationship between %HRpeak and %VO2peak for COPD patients: %HRpea k = 0.55 (+/- 0.01)%VO2peak + 43.2 (+/-1.4). Conclusion: In conclusion, the relationship between %HRpeak and %VO2peak described by ACSM is not applica ble to patients with COPD. Furthermore, this relationship does not change w ith exercise training and can be described by a single equation.