Seven female members of a university cross‐country and track team (mean age, height, and weight were 19.4 years, 160 cm, and 52.7 kg, respectively) were physiologically monitored through 1 year of training and competition. Laboratory assessment included measurement of maximal oxygen uptake (VO2max), ventilation threshold (VT), running economy, percent body fat, elapsed time to exhaustion at ... [Show full abstract] VO2max on a treadmill run, and peak grade (PG) reached on a treadmill test. Physical performance was based on elapsed time for completing the same 5 km cross‐country course at the identical time each year. A statistically significant change was noted in only two variables: elapsed time of treadmill running at VO2max (p 0.03) and 5 km run time (p = 0.04). Two variables were significantly related to 5 km run performance: PG (r = ‐0.925) and speed at VT (r = ‐0.829). The relationship of VO2max and run time was not significant (r = ‐0.287, p >0.05). The change in only one variable, percent body fat, was significantly related to change in run time (r = ‐0.82). It was concluded that a change in VO2max, VT, and running economy is not required in order for running performance to improve. Performance in running 5 km was strongly related to speed at VT and PG achieved at VO2max, whereas improvement in performance was best explained by decreased body fat.