The effects of physical activity and maturation on boys' (8 to 16 years) running economy

Abstract

Previous reports have demonstrated that running economy (RE), a measure of efficiency of locomotion, is superior in adults than in children; however, it is unclear how these differences come to be. Purpose: To identify the effect of maturity status, physical activity and various other anatomical and physiological factors on RE development in boys aged 8 to 16 years. Methods: Data were collected as part of the Saskatchewan Growth and Development Study (SGDS; 1964-1973). Using a pure longitudinal study design, anthropometric, maturity, physiological characteristics (treadmill run) and physical activity were assessed annually for nine consecutive years. Two-hundred and two eight year-old males were measured in 1965; by 1973, complete longitudinal data were available for 63 participants. During the treadmill run, a measure of submaximal oxygen consumption (VO2) was recorded, an index of RE. Four approaches of normalizing VO2 to body size were investigated. Maturity status was determined based upon chronological age at peak height velocity (PHV). Physical activity was assessed by two teacher ratings and two questionnaires. Results: Normalizing VO2 to body surface area was found to be the most appropriate body size adjustment. Submaximal VO2 (ml/m^2/min) at 9.6 km/h decreased with increasing chronological age (p