GENDER DIFFERENCES IN PRE- TO POST-TRAINING CHANGES IN VENTILATORY THRESHOLD: THE HERITAGE FAMILY STUDY

542 This study examined the gender differences in response of the ventilatory threshold to 20 weeks (3x/wk) of supervised cycle ergometry training in a biracial population of men (n=232) and women (n=208), ages 17-65 years. Participants in the HERIT AGE Family Study completed a heart rate-based training program progressing from a heart rate associated with 55% VO2max for 30 min to training at 75% VO2max for 50 min. Ventilatory threshold (VT) was estimated using V-Slope and ventilatory equivalents methods. Percent change for pre-post training values for selected variables are listed in the Table below.TableAn ANOVA between men and women across pre- post-training (Sex X Time) revealed no interaction for change in VO2max (ml·kg−1·min−1). However, there were highly significant Sex X Time interactions (p<0.0001) for improvements in VO2 at VT (VO2VT), increases in relative VT (RVT=VO2VT/VO2max * 100), increases in watts at VT (WVT), and increases in maximal watts (WMx) achieved during the post-training cycle egrometry test. These data show similar improvements in VO2max for men and woman, but strong gender differences in submaximal training-induced changes in VO2 and work at VT. This suggests that submaximal measurements of aerobic fitness reveal different aspects of improvements in fitness than the "gold standard" of VO2max. Sponsored by NHLBI HL47317 and NIH MO1-RR000400.