Exercise intensity prescription in cancer survivors: ventilatory and lactate thresholds are useful submaximal alternatives to VO2peak.

PURPOSE: Most studies with cancer survivors use percentages of peak oxygen uptake (VO2peak) for intensity prescription. Lactate or ventilatory thresholds might be useful submaximal alternatives, but this has never been investigated. Therefore, we aimed at comparing three training sessions prescribed using %VO2peak (reference), lactate thresholds, and ventilatory thresholds in terms of meeting the vigorous-intensity zone, physiological, and psychological responses. METHODS: Twenty breast (58 +/- 10 years) and 20 prostate cancer survivors (68 +/- 6 years), 3.6 +/- 2.4 months after primary therapy, completed a maximal cardiopulmonary exercise test and three vigorous training sessions in randomized order: 38 min of cycling at 70% VO2peak (M-VO2peak), 97% of individual anaerobic lactate threshold (M-IAT), and 67% between ventilatory thresholds 1 and 2 (M-VT). Heart rate (HR), blood lactate concentration (bLa), perceived exertion, and enjoyment were assessed. RESULTS: Cancer survivors exercised at 75 +/- 23, 85 +/- 18, and 79 +/- 19 W during M-VO2peak, M-IAT, and M-VT (p > .05). Sessions could not be completed in 3, 8, and 6 cases. Session completers showed HR of 82 +/- 7, 83 +/- 9, and 84 +/- 8 %HRpeak and bLa of 3.7 +/- 1.9, 3.9 +/- 0.9, and 3.9 +/- 1.5 mmol.l(-1), which was not different between sessions (p > .05). However, variance in bLa was lower in M-IAT compared to M-VO2peak (p = .001) and to M-VT (p = .022). CONCLUSION: All intensity prescription methods on average met the targeted intensity zone. Metabolic response was most homogeneous when using lactate thresholds. IMPLICATIONS FOR CANCER SURVIVORS: Submaximal thresholds are at least as useful as VO2peak for intensity prescription in cancer survivors. Overall, slightly lower percentages should be chosen to improve durability of the training sessions.