High-Intensity Exercise - Try It. You Might Like It.

Today, most people interested in fitness have heard of the concept of high-intensity interval training, or H.I.I.T., which involves very short, very strenuous bursts of exercise interspersed with periods of rest. But many people are intimidated to try such workouts.

A new study also shows that for many, just trying a H.I.I.T. workout for the first time may be a critical step in including high-intensity training as part of your everyday routine.

The study proves a different insight to some widespread assumptions about the psychological effects of intense exercise and also indicates that short, hard workouts could be a practical alternative to other forms of exercise in part because we do not hate them.

H.I.I.T. has gained considerable attention in recent years, thanks to experiments showing that even a few minutes a week of strenuous intervals improve aerobic fitness and other aspects of health as much as hours of jogging or moderate bicycle riding. But some scientists have argued that the potential physical benefits from intense training will be illusory if people do not complete the workouts, with their concerns based on past research showing that if exercise is intense, most people report not liking it. But in those studies, nonstop intense exercise was primarily examined, such as continuous, hard bicycling or running, and not interval training, which interrupts the strenuous exertion with rest periods.

So for this new study, which was published in May in Medicine & Science in Sports & Exercise, researchers decided to ask a group of ordinary people to try a variety of workouts and see if they liked them.

The researchers began by gathering 30 men and women who were inactive in general and had not tried interval training before.  They brought them into the lab, tested their fitness and familiarized them with different measures of how they felt during exercise. One of these asked them to estimate the relative intensity of a workout on a scale of 1 to 10, while another required rating the pleasantness (if any) of a workout on a similar numeric scale. They then had each volunteer complete three workouts on separate days. During one, the participants rode a stationary bicycle for 45 minutes at a steady, moderate pace. During another, they tried standard high-intensity interval training, riding hard for one minute, resting for a minute, and repeating the sequence 10 times. For the last workout, they were introduced to super-high-intensity training, consisting of pedaling as hard as they possibly could for 30 seconds three times, with two minutes of rest between each grunting bout of all-out pedaling.

Capitalizing on the rest periods between intervals, the researchers repeatedly asked the men and women to assess how they felt during their exertions and also, afterward, to rank each workout according to which had been most and least enjoyable. Then, in perhaps the most important element of the study, the volunteers where bid farewell, but asked to keep logs of their physical activities for a month, to see if people would choose to continue any of the workouts on their own.

To no one’s surprise, when the scientists reviewed the results, the cyclists proved to have unanimously reported less fatigue and more happiness during the moderate pedaling, especially if the researchers checked in near the end of either of the sessions of tiring intervals. But afterward, with the exercise behind them, people’s opinions shifted and almost all of the volunteers decided that, in retrospect, they had found the workouts almost equally enjoyable and would in fact rank the standard, high-intensity interval training as the most pleasant.

About 80 percent of them also tried at least one session of interval training in the month after the experiment, although they completed more moderate workouts in that time. These findings indicate that intervals could be less onerous than many of us probably expect. 

While perhaps not a ringing endorsement of the "joys" of strenuous exercise, the results do suggest that how you feel during a draining interval workout may not reflect how you will feel afterward, and you might even find that you wish to repeat the hard workout again.

This study was small, of course, and involved only one supervised session of each workout. It cannot tell us whether everyone will develop similar emotional responses to intense training or whether our feelings about the exercise might change with experience or greater fitness. The study also reinforces the fundamental message about intervals, which is that they are hard and physically difficult, which some people will never enjoy.

Still, if you are pressed for time, brief interval sessions might offer a viable way to fit exercise into your life. And you can’t know whether you will enjoy them or not, until you try them.