The effect of long-term strenuous resistance training on glucose effectiveness (SG) was examined by comparing 11 strength-trained and 20 sedentary males by a minimal model approach. Lean body mass (LBM) was measured by hydrostatic weighing. The LBM in strength-trained subjects (65.7 +/- 3.1 kg) was significantly larger than in sedentary subjects (56.6 +/- 1.2 kg, P < .01). The glucose disappearance constant ([KG] 3.07% +/- 0.45% min(-1)) and insulin sensitivity ([SI] 17.5 +/- 2.0 x 10(-5) x min(-1) x pmol/L(-1)) in strength-trained subjects were significantly higher than in sedentary subjects (2.06% +/- 0.14% x min(-1) and 10.3 +/- 1.2 x 10(-5) x min(-1) x pmol/L(-1), P < .05). SG in strength-trained subjects (0.024 +/- 0.003 min(-1)) was significantly higher than in sedentary subjects (0.018 +/- 0.001 min(-1), P < .05). These results thus suggest that the improved glucose tolerance in strength-trained subjects was due to increased SG and SI.