ABSTRACT: BACKGROUND:Associations between driving and physical-activity (PA) intensities are unclear, particularly among older adults. We estimated prospective associations of travel modes with total PA, sedentary time (ST), light-intensity PA (LPA), and moderate-to-vigorous intensity PA (MVPA) among adults aged 39-70?years. METHODS:We studied 90?810 UK Biobank participants (56.1?±?7.8?years). Driving status, specific travel modes (non-work travel; commuting to/from work) and covariates were assessed by questionnaire (2006-10). PA was assessed over 7?days by wrist-worn accelerometers (2013-15). We estimated associations using overall and age-stratified multivariable linear-regression models. RESULTS:Drivers accumulated 1.4% more total PA (95% confidence interval: 0.9, 1.9), 11.2?min/day less ST (-12.9, -9.5), 12.2?min/day more LPA (11.0, 13.3) and 0.9?min/day less MVPA (-1.6, -0.2) than non-drivers. Compared with car/motor-vehicle users, cyclists and walkers had the most optimal activity profiles followed by mixed-mode users (e.g. for non-work travel, cyclists: 10.7% more total PA, 9.0, 12.4; 20.5?min/day less ST, -26.0, -15.0; 14.5?min/day more MVPA, 12.0, 17.2; walkers: 4.2% more total PA, 3.5, 5.0; 7.5?min/day less ST -10.2, -4.9; 10.1?min/day more MVPA, 8.9, 11.3; mixed-mode users: 2.3% more total PA, 1.9, 2.7; 3.4?min/day less ST -4.8, -2.1; 4.9?min/day more MVPA, 4.3, 5.5). Some associations varied by age (p interaction?