Background and aim No prospective studies have investigated the association between physical activity (PA) and carotid subclinical cardiovascular disease across childhood. Therefore, the primary aim was to investigate the association between PA intensity across childhood and carotid intima media thickness (cIMT) and stiffness in adolescence. Second, we included a clustered cardiovascular disease risk score as outcome.

Methods This was a prospective study of a sample of 254 children (baseline age 8–10 years) with a 6-year follow-up. The mean exposure and the change in minutes of moderate-and-vigorous and vigorous PA intensity were measured using the Actigraph activity monitor. Subclinical cardiovascular disease was expressed as cIMT, carotid arterial stiffness and secondarily as a metabolic risk z-score including the homoeostasis model assessment score of insulin resistance, triglycerides, total cholesterol to high-density lipoprotein ratio, inverse of cardiorespiratory fitness, systolic blood pressure and the sum of four skinfolds.

Results No associations were observed between PA intensity variables and cIMT or carotid arterial stiffness (p>0.05). Neither change in PA intensity (moderate-and-vigorous nor vigorous) nor mean minutes of moderate-and-vigorous PA intensity was associated to the metabolic risk z-score in adolescence (p>0.05). However, a significant inverse association was observed between mean minutes of vigorous PA and the metabolic risk z-score in adolescence independent of gender and biological maturity (standard β=–0.19 p=0.007).

Conclusions A high mean exposure to, or changes in, minutes spent at higher PA intensities across childhood was not associated to cIMT or stiffness in the carotid arteries in adolescence. Our observations suggest that a high volume of vigorous PA across childhood independently associated with lower metabolic cardio vascular disease risk in adolescence.