Waist circumference and BMI are independently associated with the variation of cardio-respiratory and neuromuscular fitness in young adult men

Objective: To test two hypotheses: (1) cardiorespiratory (CRF) and neuromuscular (NMF) fitness is associated with body mass index (BMI) and waist circumference (WC), independent of each other and of leisure-time physical activity; (2) individuals with high CRF and NMF have lower WC for a given BMI, compared with those with low CRF and NMF. Design: Cross-sectional study. Setting: Men participating in refresher training organized by the Finnish Defence Forces. Participants: A total of 951 men (mean age 29.1, s.d. 4.2 years; BMI 25.3 kg/m 2 , s.d. 3.8; WC 91, s.d. 11 cm). Main outcome measures: Body mass index, WC, maximal oxygen uptake (VO 2 max), height of vertical jump, number of push-ups and sit-ups during a 1-min test, static back extension endurance, isometric grip strength, self-reported leisure-time vigorous physical activity. Multiple linear regressions were used to explain the variation in fitness. Results: Waist circumference had significant ( P