The easiest thing about working out is how easy it is to get bored. Repetitive workouts such as following the same cardio and strength routines, the same swim patterns or the same yoga class, can bore the mind and also become less stimulating, and therefore less effective for the body.

One great way to keep the body guessing and to beat mental and physical boredom is interval training. Originally used to help athletes increase strength and stamina, interval training uses the body’s aerobic and anaerobic systems in the same workout, resulting in higher calorie loss, an increase in oxygen delivery, stronger heart muscle and, ultimately, a body that operates more efficiently.

Interval training in the pool can be easy to do and to keep fresh. Participants can either do a “total cardio” interval training session, or a cardio plus strength interval training session. In either method, participants should think of working in two alternating modes: “bursts” and “recovery.”

In a total cardio session, individuals perform their usual aqua cardio exercise at different rates. For example, when swimming laps, aqua jogging or doing aqua aerobics, begin by performing four minutes at the “recovery” rate, which is at the low end of aerobic intensity (65- to 70 percent of target heart rate, or 5 to 6 on the modified Borg Scale) followed by two minutes of a “burst” at a higher intensity (80- to 90 percent of target heart rate, or 8 to 9 on the modified Borg scale).

Repeat this pattern for a slightly shorter period of time than the customary cardio workout time. As this pattern becomes easier, work to match the number of minutes at lower and higher intensities. For example, two minutes of each repeated 10 times is a 40- minute workout.

For a cardio plus strength session, aerobic exercise is the burst phase and strength training is the recovery phase. For example, a person could swim five minutes of laps at the higher end of his aerobic intensity (80 percent of target heart rate or 8 on the Borg scale), then do three minutes of lunges and triceps presses. Follow that up with five more minutes of swimming and three minutes of biceps curls and chest presses. 

When beginning interval training, add the interval sessions slowly, starting with one per week. Feel free to mix and match, depending on the participant’s goals.

Keep in mind that the heart rate guidelines are guidelines only; many medications and individual physiology can affect a participant’s heart rate.

  • Beats Per Minute

220 minus your age times percentage of maximum heart rate. Example: a 40-year-old’s low (65 percent of maximum heart rate) and high (85 percent of maximum heart rate) heart rates are:
220-40 = 180 x .65 = 117 bpm

220-40 = 180 x .85 = 153 bpm

  • Modified Borg Scale of Perceived Exertion

Level 1: I just woke up and haven’t even hit the alarm button.
Level 2: I'm comfortable and could maintain this pace all day.

Level 3: I'm still comfortable, but am breathing a bit harder.

Level 4: I’m working a little bit; on land I’d have broken a sweat. 

Level 5: I can still talk easily and sing.

Level 6: I can still talk, but can’t sing.

Level 7: I can still talk, but I don't really want to.

Level 8: I can grunt in response to your questions and can only keep this pace for a short time period.

Level 9: I can’t do this much longer.

Level 10: I am climbing Everest without oxygen.