Growing up, I was a competitive endurance swimmer. During meets, I swam events like the 1500 meter (~1 mile) freestyle. For me, training meant between two and four hours of practice in the pool every day, swimming lap after lap (after lap after lap). The conventional exercise wisdom doesn’t leave many alternatives – if you want to increase your endurance, you’ve just got to put in the hours. Or do you?
High intensity interval training (HIIT) has been increasing in popularity over the past few years, with programs like Insanity and Crossfit gathering a huge following among athletes, both recreational and competitive alike. As a graduate student, what attracted me to these programs was their efficiency – in 20 minutes or less, I could see the same long-term health benefits as if I spent an hour or more sweating it out? Sign me up!
So, does HIIT work? According to the latest research, the answer is a definitive ‘Yes’. A 2012 study compared two exercise regimens, a high-intensity interval workout and an endurance workout, both using a stationary bike. The HIIT approach involved 30 seconds of cycling at maximum effort, followed by 4.5 minutes of ‘active’ rest (low-effort pedaling). Participants completed this workout three times per week for six weeks. The endurance (classic) approach involved 40-60 minutes of cycling, at 65% effort (pushing hard, but not gasping for breath). Participants in this group worked out five times per week for six weeks. Two common measures of physical fitness, peak oxygen consumption and time-to-exhaustion, were used to determine differences before and after the six weeks of training.
Amazingly, both groups saw virtually the same improvement in physical fitness, based on the two measures collected. However, the HIIT group saw these improvements with only one hour per week of training, while the endurance group logged 4-6 hours each week.
HIIT seems like it may allow busy people the opportunity to reap the same health benefits of exercise in less time – but is it for everyone? Some evidence suggests that these programs may be less appropriate for people with pre-existing medical conditions, like congestive heart failure, because of the ‘stress’ they put on the body. For these people, lower intensity endurance exercise has shown to be more beneficial for improving overall health and functioning.
However, if your busy schedule is the primary thing keeping you from exercising, HIIT offers a potential solution – after I started critically evaluating these programs, I realized that I just couldn’t use the ‘I don’t have time to exercise’ excuse any more. Now I always make sure to fit in at least three HIIT workouts a week. If you’re looking for a way to fit exercise into your schedule, I encourage you to explore some of the HIIT programs out there to see if they might be right for you.
Photo credit: http://www.dailymail.co.uk/health/article-2033197/How-vigorous-workout-burning-calories-day.html