The conundrum of exercise dose: when the unknown gets knowable

The motto "Exercise is a medicine" has reached plethoric tone and the beneficial effects of exercise are tions of regular physical activity (PA) and exercise are well documented and represent an essential component of primary and secondary prevention strategies [1,2]. However, when it comes to prescription and adherence to exercise training and programs, these behavioural interventions have showed limited efficacy [3]. As a result, physical inactivity remains largely prevalent among general and unhealthy populations. In addition, for people with several chronic diseases, physical inactivity is an increasingly worsening factor. The concept of optimal dose of exercise is still a matter of debate. This is the key for designing individually tailored programs so to yield health benefits, at the minimally conceived level. In a pandemic context of environmental syndromic factors, dose-response studies are urgently advocated to determine the clear-cut therapeutic effects and the multiple health-promoting benefits of exercise.