Age at puberty and accelerometer-measured physical activity: Findings from two independent UK cohorts

Background It is unclear if puberty timing influences future physical activity (PA).Aim To investigate the association of puberty timing with PA across adolescence and adulthood.Subjects and methods Data were from two British cohorts. Participants from an adolescent birth cohort (females = 2349, males = 1720) prospectively reported age at menarche and voice break and had PA recorded by Actigraph accelerometers at ages 14 years and 16 years. A cohort of middle-aged and older adults (40–70 years; females = 48,282; males = 36,112) recalled their age at puberty and had PA (mean acceleration; mg) measured by AxivityAX3 accelerometers.Results After adjustment for age, education, smoking and BMI, per 1-year older age at menarche was associated with higher mean counts/minute at age 14 years (0.07 SD counts/minute; 95% CI = 0.04–0.11) with associations attenuated at age 16 years (0.02; −0.03–0.07). Differences in mean acceleration per older year at menarche were close to the null in women aged 40–49 years (0.02 mg; 0.01–0.03), 50–59 years (0.01; 0.00–0.02) and 60–70 years (0.01; 0.00–0.01). Age at voice break and PA associations were close to the null in both cohorts.Conclusion We found a positive association between puberty timing and PA in females which weakened at older ages and limited evidence of an association at any age in males.