In practice when swimmers swim prescribed distances during a specific period of time, i.e. swim 100 meters in two minutes.If a swimmer finishes in 1:40, then he has 20 seconds to rest. Also called repeats.
Periods of intense physical activity alternating with periods of recovery, allowing longer training time at your own peak performance levels.
a structured method of training that alternates brief, hard efforts with short periods of easier riding for partial recovery.