Test for significant linear and nonlinear relationships between survival and MET-hours/d of total exercise in walkers.

*Hazard ratios (95% confidence intervals) from Cox proportional hazard analyses. † Semi-hazard ratios (95% confidence intervals) from competing risk regression analyses. All analyses adjusted for age (age, age2), race, sex, education, prior heart attack, aspirin use, and intakes of red meat, fruit, and alcohol. Total mortality also adjusted for cancer history.