Forty male and 40 female rats were randomly assigned to 1 of 4 experimental groups. Half of the animals of each gender were exercised by jumping (weighted by a vest with up to 70% body weight) to a height of 16 cm 20 times X d-1 (30 s between jumps) 5 d X wk-1 for 8 wk. Half of the exercised animals and half of the sedentary animals were injected with the anabolic steroid durabolin (0.2 mg in 0.1 ml sesame seed oil) 6 d X wk-1 for the last 3 wk of the 8-wk exercise program. The other animals were injected with 0.1 ml of sesame seed oil (as a placebo) on the same schedule. At the end of the 8-wk program, blood was drawn from the right atria of the anesthetized animals. Plasmas were analyzed for total cholesterol (TC) and high density lipoprotein cholesterol (HDL-C) concentrations. Low density lipoprotein cholesterol (LDL-C) concentration was estimated as the difference between these two parameters (TC - HDL-C). A three-factor analysis of variance (2 X 2 X 2) demonstrated that there was a significant (P less than 0.05) gender effect (males greater than females), but no steroid or exercise main effects for TC. There were significant (P less than 0.05) steroid and exercise main effects for both HDL-C and estimated LDL-C, as well as a significant gender main effect for estimated LDL-C (but not HDL-C).(ABSTRACT TRUNCATED AT 250 WORDS)