INFLUENCE OF TRAINING, SEX, AGE AND BODY-MASS ON THE ENERGY-COST OF RUNNING

To highlight the influences of age, sex, body mass (m(b)) and running training on the energy cost of running (C(r)) young basketball players [38 boys (BB) and 14 girls (BG), aged 14.2 (SD 0.3) and 12.2 (SD 1.9) years, respectively] were selected to be compared to middle-distance runners [27 men (MR) and 14 women (FR) aged 23.7 (SD 3.4) and 23.9 (SD 4.1) years, respectively]. The C(r) was measured during a maximal treadmill test. In each group C(r) and body mass (m(b)) and body height were negatively and significantly correlated. A stepwise regression showed that among both the body dimensions measured, m(b) was the most important factor in determining the variations of C(r). For the whole group (n=93) the correlation coefficient was 0.72 (P<0.0001). For a given m(b), there was no significant difference between the C(r) of BG, BB and MR: this result would support the hypothesis that the differences in C(r) currently attributed to age, running training or sex differences are mainly related to m(b). On the other hand, for a given m(b), FR showed a significantly lower C(r) than the basketball players (P<0.01 for BG and BB) and than MR (P<0.05), thus suggesting that women decrease their C(r) as a response to running training more efficiently than do men.