274 A synergism between growth hormone and testosterone is known to exist in men. However, the effects of chronic training on adaptations of these hormones to acute resistance exercise and their relationship to muscular hypertrophy remain to be fully elucidated, particularly in women. This study examined the effects of 6 months of resistance training on acute exercise-induced responses of immunoreactive growth hormone (IGH), total testosterone (TT), and free testosterone (FT), 1RM squat strength (strength) and thigh muscle cross-sectional area (TMCSA) in 38 women. A total body training group (TBTG; n=22) and an upper body training group (UBTG; n=18) and trained 3 days/wk for 6 months in a periodized fashion (repetitions varied between 8 and 12, rest intervals between sets varied between 45 and 90 secs). A 20-30 minute aerobic conditioning session followed each workout. Venous blood samples were obtained pre and post an acute resistance exercise test ([ARET] 6 sets of 10RM squats separated by 2 min rest periods) and MCSA was assessed via magnetic resonance imaging on three separate occasions during training (month 0 [T1] month 3 [T2] and month 6 [T3]. An ANOVA with repeated measures (p≤0.05) revealed significant training and interaction effects. Mean±SD: TBTG (strength(kg): T1=54±12, T2=63±11, T3=69±14); (MCSA (cm2): T1=126±17, T2=129±15, T3=133±14); UBTG (strength (kg): T1=52±10, T2=58±10, T3=59±9); (MCSA (cm2): T1=123±18, T2=122±17, T3=126±17). The T1%ΔFT for ARET was significantly associated with T1 to T3 MCSA Δs (r=0.35). The ARET induced elevations in IGH, TT, and FT and training X pre- post ARET interactions suggest that concomitant with increases in strength and hypertrophy after chronic heavy resistance training are alterations in the hormonal milieu after acute resistance exercise.