The effect of anabolic steriod treatment on maximum oxygen intake, mile run time, skin fold thickness, body weight, and elbow flexion and knee extension strength was studied. Twenty-one male college students, ages 19–33, engaged in an interval running program six days a week over a three week period. Each subject supplemented their diets with one half gram/kilogram of body weight of 90% protein powder. A double blind design was used for the administration of the steroid treatment with each of the subjects in the treatment group receiving six mg of stanozolol per day. Pre and post treatment tests were administered for each of the dependent variables. There was improvement at the .05 level in the oxygen uptake of both treatment and control groups. For the other dependent variables, the differences between pre-treatment and post-treatment values were not statistically significant. Differences between the steroid and the control groups were not statistically significant for any of the dependent variables. When young male adults are engaged in an endurance training program, steroid treatment does not appear to have any effect on the development of endurance or strength, or on the percent of body fat.