Abstract

This investigation examined endurance runners during a 3-week reduction in training volume and frequency. Ten well-conditioned runners were monitored for 4 weeks while training at their normal weekly training distance (81+/-5 km/wk, 6 d/wk). This period was designated as baseline training (BT). Sixty km/wk were run at ca. 75 VO2max, and the remainder (21 km/wk) at ca. 95 VO2max in the form of intervals and races. The runners then reduced weekly training volume (RT) by 70 of BT to 24+/-2 km/wk and frequency by 17 to 5 days/wk for 3 weeks. During RT 17 km/wk was performed at ca. 75 VO2max and the remainder (7 km/wk) at ca. 95 VO2max (intervals and races). The runners were tested weekly and performed 5-km races on a 200-m indoor track during BT and after 2 and 3 weeks of RT. Maximal heart rate (HR) increased by ca. 4 beats/min at RT week 3, which may have been associated with a decrease in estimated plasma volume of 5.62+/-0.43. Time to exhaustion during the VO2max tests increased by 9.5 at RT week 3. No significant changes occurred with RT in body weight, body fat, overall 5 km race times, VO2max, muscular power (vertical leap and Margaria power test), and citrate synthase activity (at 2 weeks of RT). No alterations in venous lactate, energy expenditure, and HR were observed during submaximal running at two speeds (ca. 65 and 85 VO2max) with RT. It was concluded that reduced training maintained many endurance training adaptations and racing performance in these well-trained runners for 3 weeks. Verf.-Referat