Interval training is a type of physical training that involves a series of low- to high-intensity exercises interspersed with rest or relief periods. The high-intensity intervals are typically at or near anaerobic exercise, while the recovery periods involve activity of lower intensity. Interval training can be applied to both aerobic and anaerobic exercise.
Aerobic interval training (AIT) generally consists of repeating bouts of medium to high intensity aerobic exercise separated by short recovery periods of either complete rest or active recovery (exercise at a lower intensity). The duration and number of repetitions in each bout depends on the desired outcome, but AIT workouts typically last 20–60 minutes. For beginner athletes, AIT may start with 2–3 sets of 6–8 repetitions per workout, while more experienced athletes may perform 4–5 sets of 8–12 repetitions.
Anaerobic interval training (ANAET) usually consists of all-out sprints or near maximal effort exercises separated by active or passive recovery periods. The work:recovery ratio is typically 1:2 – meaning that for every 1 second spent working, 2 seconds are spent recovering. However, this ratio can be adjusted depending on the athlete’s goals and level of fitness. For example, beginners may use a 1:1 work:recovery ratio while more experienced athletes may use a 1:3 ratio. ANAET workouts typically last 10-30 minutes.
The benefits of interval training are numerous and well-documented. In terms of cardiovascular health, AIT has been shown to improve heart function and increase VO2max (a measure of the body’s ability to consume oxygen during exercise). AIT has also been shown to decrease blood pressure and resting heart rate, as well as improve insulin sensitivity (a marker for diabetes risk). In terms of athletic performance, interval training has been shown to improve running economy (the amount of energy required to run at a given pace), time trial performance, and VO2max .
Interval training is an effective way to improve cardiovascular health and athletic performance. Beginners should start with 2-3 sets of 6-8 repetitions per workout, while more experienced athletes may perform 4-5 sets