Exercise training of a muscle group improves local vascular function in subjects with chronic heart failure (CHF). We studied forearm resistance vessel function in 12 patients with CHF in response to an 8-wk exercise program, which specifically excluded forearm exercise, using a crossover design. Forearm blood flow (FBF) was measured using strain-gauge plethysmography. Responses to three dose levels of intra-arterial acetylcholine were significantly augmented after exercise training when analyzed in terms of absolute flows (7.0 +/- 1.8 to 10.9 +/- 2.1 ml x 100 ml(-1) x min(-1) for the highest dose, P < 0.05 by ANOVA), forearm vascular resistance (21.5 +/- 5.0 to 15.3 +/- 3.9 ml x 100 ml forearm(-1) x min(-1), P < 0.01), or FBF ratios (P < 0.01, ANOVA). FBF ratio responses to sodium nitroprusside were also significantly increased after training (P < 0.05, ANOVA). Reactive hyperemic flow significantly increased in both upper limbs after training (27.9 +/- 2.7 to 33.5 +/- 3.1 ml x 100 ml(-1) x min(-1), infused limb; P < 0.05 by paired t-test). Exercise training improves endothelium-dependent and -independent vascular function and peak vasodilator capacity in patients with CHF. These effects on the vasculature are generalized, as they were evident in a vascular bed not directly involved in the exercise stimulus.