Table 1 Subject descriptive data. Data are means (± standard deviation). Men (n = 10) Women (n = 10) Age (years) 19.9 (.5) 20.1 (.7) Body mass (kg) 68.3 (2.5) 56.3 (1.8) * Body height (m) 1.79 (.02) 1.64 (.01) * Percent body fat 11.1 (1.1) 17.5 (1.6) * VO2max (ml·kg·-1·min-1) 78.3 (4.0) 64.3 (2.4) * Heart rate at ventilatory threshold (beats·min-1) 159 (2) 158 (3) * indicates difference between males and females (p < 0.05). The ventilatory threshold for each subject was determined by noting the point where an abrupt increase in VE·VO occurred without a concomitant increase in VE·CO as a measure of the lactate threshold (Haverty et al., 1988) and the heart rate measured at this point was considered to be the heart rate at ventilatory threshold.