Heartbeat: Is all physical activity beneficial for cardiovascular health?

There is considerable evidence to support the beneficial effects of exercise on cardiovascular health. However, it remains controversial whether physical exertion in the workplace provides the same benefit as sports physical activity (PA). In a study of 3576 employed men with no cardiovascular disease (CVD) at baseline, low levels of occupational PA were associated with a higher risk of CVD events over a median follow-up of 14 years compared with those with moderate occupational PA (1.66, 95% CI 1.06 to 2.59) but higher levels of occupational PA were not associated with a reduced risk of CVD.1 Congruent with previous studies, sports PA was associated with reduced CVD event rates but the protective effect of sports PA was only seen in sedentary workers. Paradoxically, men with high levels of occupational PA who also engaged in recommended levels of sports PA paradoxically had higher CVD event rates (table 1).2 View this table: Table 1 Risk factors-adjusted HRs (with 95% CIs) for SpPA in different OPA categories, and test for SpPA–OPA interaction on the incidence of CHD and CVD events In the accompanying editorial, Coenen1 suggests several possible explanations for this apparent paradox including differences in the duration or intensity of occupational versus sports PA, inadequate recovery times after activity, confounding lifestyle factors or methodological limitations in self-reporting of activity compared with accelerometer data. Even so, he concludes: ‘The benefits of being physical active are apparent and undeniable in primary and secondary (cardiovascular) disease prevention. However, it appears important that clinicians (including cardiologists) …