Alactic, or “intensive,’ intervals train the explosive power of the alactic system as well as the aerobic capacity to recover in between alactic bouts. The basic principles of alactic intervals are: • Use short work periods around 5 seconds long • Generate as much power during the work periods as possible while maintaining proper technique • Actively recover for 1-2 minutes between work periods • Maintain the same level of power output from one work period to the next • Perform 10-20 sets, depending on the athlete’s ability to maintain a consistent power output during work periods You can measure if this method is improving conditioning over time by looking at two markers:

1. An increase in the number of work periods the athlete can do while sustaining the same power output
2. An increase in the power the athlete generates during work periods Focus on coaching dynamic energy control as athletes bring their heart rates back down between work periods. It’s also important to ensure that athletes don’t compromise posture or technique for short-term increases in explosiveness. You can use a variety of exercises to perform alactic intervals, but they must be explosive and ideally have some measure of distance. Both the work period exercises and the active recovery movements can vary throughout the training session. As you approach a competitive season, work and rest intervals should more closely mimic those of the sport itself.