The simple instrument for self-reported PA introduced by Saltin and Grimby has been shown to discriminate between sedentary and active counterparts regarding maximum oxygen uptake (17) and has been validated against biological measures (18). Indeed, studies have indicated that such single self-reported approximation of the level of PA, may predict risk for morbidity and cardiovascular as well as total mortality (19-21). The self-assessed PA-level concurs well with the actual physical fitness of the individual (22-24). This is also important, since cardiorespiratory fitness may also predict cardiovascular risk and mortality (25).