Physiological adjustments to intensive interval treadmill training

Abstract

During a one month training period, eight active men, aged 23-35 years, completed sixteen 30 minute sessions of high intensity interval (5 second work bouts at 16.9 km/hr up 20-25% grade alternated with 10 second rest intervals) treadmill work. In this training period, V̇O 2 , V̇ E and blood lactate in a 10 minute run at 12.9 km/hr on a level treadmill were unchanged but heart rate during this work decreased by an average of 9 beats/min. During a 4 minute interval work effort at the training intensity, blood lactate accumulation decreased by 40.4%. In exhausting work, mean values of V̇O 2 , V̇ E and blood lactate increased by 6.2%, 8.2% and 31.6% respectively. Maximal heart rate decreased by an average of 4 beats/min. The average work production of the men in the training sessions improved by 64.5% from 28,160 kgm to 43,685 kgm. No significant improvements were observed in either a short sprint or a stair climbing test which assessed the ability to generate mechanical power from alactacid anaerobic sources. It was concluded that the training regime is an effective method of producing a high total work output in competitive athletes and results in improvements in aerobic power, glycolytic capacity and ability to tolerate the short duration interval work encountered in many games.