Purpose: Cardiorespiratory fitness (CRF) is generally regarded as an objective and reproducible measure of recent habitual physical activity (PA). Considering that the majority of daily PA is performed at light intensity, it is likely that CRF benefits will be detected at submaximal rather than maximal exercise. The purpose of this study was to evaluate daily minutes of light (LIPA), moderate (MIPA) and vigorous (VIPA) intensity physical activity among men with cardiovascular disease (CVD), and to determine the relation between PA and submaximal (oxygen uptake efficiency slope (OUES)) and maximal (V̇O2 peak) indices of CRF. Methods: A total 32 male participants (mean ( SD): age of 60.0 ± 8.7 yr, V̇O2 peak (L/min) 2.0  0.45, V̇O2 peak (mL/kg/min) 23.3  5.7, were recruited during an induction to a community based exercise referral program following completion of phase 2 cardiac rehabilitation. Participants underwent a graded exercise test on a cycle ergometer with breath by breath open circuit spirometry after which they wore a wrist worn accelerometer (Actigraph) for 7 d. Absolute and relative submaximal OUES were calculated by plotting V̇O2 in mL/min on the x axis, and the log transformed VE on the y axis (V̇O2 = a log 10 VE + b). Exercise data up to the ventilatory anaerobic threshold was included in the analysis. Results: Participants performed 589.05  69.41 min of daily LIPA, 161.38  66.16 min of MIPA and no daily min of VIPA. There was no significant relation between peak V̇O2 and either LIPA or MIPA. There was a significant correlation between submaximal OUES (r=0.44; p<0.01) and LIPA. The relation between submaximal OUES/kg and LIPA min almost reached statistical significance (r=0.33; p<0.07). There was no significant relation between MIPA and OUES or OUES/kg. Conclusion: Men with CVD spend the majority (78%) of their day performing LIPA. OUES, a submaximal measure of CRF was related LIPA whereas no relation was found between V̇O2 peak and LIPA.