Weird Full article: http://www.sportsci.org/jour/0101/cf.htm Researchers from Canada?s McMaster University recently investigated the effects of interval exercise on VO2max (MacDougall et al., 1998). Training was performed on a stationary cycle ergometer for three days each week. The program began with four intervals lasting 30 s, separated by a 4-min rest period. By Week 7 the number of intervals had increased to 10, while the rest intervals were gradually reduced to 2.5 min. VO2max increased by 9%, demonstrating that significant gains in VO2max could be achieved from exercise of a relatively short duration. In the first week of the program, each training session lasted 14 min. By Week 7, the length of each training session had increased to 30 min. A team from Japan?s National Institute of Fitness and Sport found that a high-intensity intermittent training program achieved bigger gains in VO2max than a program of steady cycling (Tabata et al., 1997). Active male subjects were assigned to one of two groups, each training 5 days per week for 6 weeks. One group followed a training program involving 60 min of moderate intensity exercise (70% VO2max), for a total of 5 hours per week. The VO2max in this group improved by an average of 9%. Training sessions of the other group consisted of eight all-out work bouts, each lasting 20 s, with 10 s of rest. This group cycled for a total of only 20 min per week, yet their VO2max improved by 15%, In addition to its effect on VO2max, high-intensity intermittent training can improve athletic performance. Lindsay et al. (1996) reported that 4 weeks of interval training can improve 40-km time trial performance of competitive cyclists. The cyclists replaced approximately 15% of moderate intensity endurance training with high-intensity intermittent training, completing six interval sessions during the course of the study. Each interval session consisted of six to eight 5-min work bouts at 80% of peak power, separated by 60 s of recovery. The authors found significant improvements in 40-km time trial performance (54.4 ? 3.2 vs 56.4 ? 3.6 min) and time to fatigue at 150% of peak power (72.5 ? 7.6 vs 60.5 ? 9.3 s). In a similar study, Stepto et al. (1999) examined the effect of five different types of interval training on performance of a 40-km time trial. The cyclists were assigned to one of five groups. Each group followed a different program, as shown in Table 1.
