A five year physiological case study of an Olympic runner.

OBJECTIVE: To study physiological changes caused by long term endurance training in a world class female distance runner, and to compare these changes with alterations in 3000 m running performance. METHODS: The subject underwent regular physiological assessment during the period 1991-1995. Physiological measures made included body composition, maximal oxygen uptake (VO2MAX), running economy, and lactate threshold. In addition, the running speed at VO2MAX was estimated. Test protocols, laboratory equipment, and laboratory techniques used were the same for each test session. RESULTS: The 3000 m race performance improved by 8% from 1991 to 1993 after which it stabilised. In contrast, VO2MAX fell from 1991 (73 ml/kg/min) to 1993 (66 ml/kg/min). Submaximal physiological variables such as lactate threshold (from 15.0 to 18.0 km/h) and running economy (from 53 ml/kg/min to 48 ml/kg/min at 16.0 km/h) improved over the course of the study. Despite no increase in VO2MAX, the reduction in the oxygen cost of submaximal running caused the estimated running speed at VO2MAX to increase from 19.0 km/h in 1991 to 20.4 km/h in 1995. CONCLUSIONS: Improvement in 3000 m running performance was not caused by an increase in VO2MAX. Rather, the extensive training programme adopted, together perhaps with physical maturation, resulted in improvements in submaximal fitness factors such as running economy and lactate threshold. These adaptations improved the running speed estimated to be associated with VO2MAX, and resulted in improved 3000 m running performance.