LESMES, GEORGE R., EDWARD L. FOX, CAROL STEVENS, AND ROBERT OTTO. Metabolic Responses of females to high intensity interval training of different frequencies. Med. Sci. Sports. Vol. 10, No. 4, pp. 229-232, 1978. The purpose of this investigation was to examine the effects of frequency and distance of high intensity, interval training on females. Thirty-two females participated in an eight-week program of interval run training. Subjects were assigned to either a 2 day/week or a 4 day/week group, as well as a high intensity, short distance (50, 101, 201 meters), or high intensity longer distance (604, 805, 1208 meters) group. Estimates of training intensity were 170% and 130% V̇o2max for the short and longer distance groups, respectively. Maximal and submaximal measures of oxygen consumption (V̇o2), heart rate (HR), and venous blood lactic acid were determined prior to and following the training program. After training, there was a significant increase (P < 0.01) in V̇o2max (13%) (ΔJOURNAL/masis/04.02/00005756-197810040-00001/ENTITY_OV0335/v/2017-12-20T204311Z/r/image-png = 0.32 1/min or 5.2 ml/kg•min). Maximal V̇E in creased approximately 12% after training (P < 0.01). Max HR, max lactic acid, and submax V̇o2 were not altered by the training. However, HR submax decreased significantly (P < .05) after training by approximately 6%. Analysis of covariance indicated that these changes were independent of training frequency, distance, and intensity. It was concluded that the changes in aerobic power and submaximal HR of females are independent of frequency, distance, and intensity of high-intensity interval training programs.