Table 1.

Deriving a Modeled Estimate of the Association Between PA and Health Outcomes at Any Level of PA Using the Results From These Meta‐Analyses

The results reported in this article (displayed in Table 4) collapse the modeled relationship between PA and health outcomes across a continuous PA metric to a single parameter in order to provide comparable results across disease outcomes. These parameters can be used to estimate the modeled association between PA and health outcome for the difference between any two levels of PA. For example, the meta‐analysis of CVD incidence using an Additional or Marginal METs approach suggests that the RR for a change from 0 MET h/day to 1.61 MET h/day (equivalent to 11.25 MET h/week) is 0.83. These values can be put into equation (1) to obtain the estimate b=−0.15. $$\text{RR}=1+\text{b MET}{\text{hr/day}}^{0.25}$$ (1) This can then be used to estimate the RR for a unit increase of MET h/day at any PA level. For example, the RR of CVD incidence associated with a change from 2 to 5 MET h/day is estimated as follows: $${\text{RR}}_2=1-0.15\times 2^{0.25}=0.82$$ $${\text{RR}}_5=1-0.15\times 5^{0.25}=0.77$$ $${\text{RR}}_{2\to 5}=\frac{{\text{RR}}_5}{{\text{RR}}_2}=0.94$$

CVD indicates cardiovascular disease; MET, metabolic equivalent of task; PA, physical activity; RR, relative risk.