The purpose of this investigation was to examine the effects of a reduction in training volume (RT) (8 km/day, 5 days/wk, for 10 days) in five highly trained collegiate distance runners. The subjects were tested midseason (MS) (110 km/wk), after a 10-day taper (80 km/wk) and subsequent championship meet (post-championship, PC), and post RT. PC data represent the runners at their peak performance capacity. Maximal oxygen consumption, maximal heart rate (HR), and time to exhaustion during the max tests, as measured at PC and RT, were not altered. Other parameters were measured for all conditions. No changes were observed in body weight and percent body fat (p greater than 0.05). Submaximal treadmill runs (TR) at 265 and 298 m/min revealed no alterations in VO2 submax, ratings of perceived exertion (RPE), HR and 2-min post-run lactate levels (p greater than 0.05). The HR during a 6-min track run (265 m/min) significantly increased (p less than 0.001) by 10 bts/min with RT vs MS and PC, which may be a result of mechanical or psychological changes. After RT, 1-min recovery HR (HRr) for the track run and 1- and 2-min post-TR were significantly elevated by 16, 12, and 12 bts/min, respectively. It is not apparent what role HRr serves as an indicator of fitness level and performance capability during reduced training. These results suggest that the reduced training program used did not sufficiently diminish nor improve aerobic capacity in highly trained distance runners.