The ACSM’s top fitness trend for 2014 is high intensity interval training (HIIT).
“High Intensity Interval Training made its first appearance on this list this year. Its appearance in the top spot on the list reflects how this form of exercise has taken the fitness community by storm in recent months,” said Walter R. Thompson, Ph.D., FACSM, lead author of the survey of 3,815 health and fitness professionals worldwide, in the ACSM news release.
Serious athletes have been using interval training for a long time to increase speed and endurance. What’s new is the higher-level intensity that promises to accomplish the same benefits of continuous moderate-intensity exercise in about half the time. HIIT involves repeating short bursts of activity followed by a short period of rest or recovery, e.g. for a total time of less than 30 minutes.
In this recent story in The Globe and Mail, Dr. Martin Gibala, Ph.D, a researcher and professor of kinesiology at McMaster University says, “there is good evidence that HITT can provide superior physiological benefits, at least over the short term. This was the conclusion of a recent systematic review that was published in the British Journal of Sports Medicine.”
A systematic review looks at existing evidence across many studies and in this case there were 10. The key finding was that among 273 participants with chronic diseases, including coronary artery disease, heart failure, hypertension, metabolic syndrome and obesity, there was a significantly higher increase in the VO2peak among those who used HIIT compared to MICT (moderate-intensity continuous training). VO2peak is a measure of your maximal oxygen uptake, a measure of cardiorespiratory fitness and aerobic endurance. You can read the BJSM abstract here.
So HITT appears to have a significant benefit for those with chronic cardiovascular diseases. But what about for other people? Who should be using HIIT as part of their workout program?
For the athlete who’s already doing intervals, upping the intensity with short bursts of speed may provide new benefits.” Your cardiovascular system gets stronger and pushes more oxygen-rich blood through your body. Muscles get better at using that oxygenated blood. Your stride becomes more efficient as coordination between the muscles and nervous system improves. The perks may even extend to reducing your risk for chronic diseases by improving blood sugar control.
And Joe McConkey, M.S., exercise physiologist and coach at the Boston Running Center added:
Running superfast does increase the risk of injury, however. You need to be strong and flexible and have a solid base of both mileage and speedwork to safely do this training. You’re ready for HIIT workouts if you’ve been running four to five times a week for at least four months, regularly doing some runs at paces 60 to 90 seconds per mile faster than easy pace, and completing a weekly long run of at least 50 minutes. In terms of strength and flexibility, you should be able to hold a squat position for 90 seconds and, while standing, grab and touch your heel to your butt, feeling only a minor stretch in your quad. Start with one HIIT session a week, and build up to no more than two in a 10-day period.
After seeing how intervals have been increasing my endurance in spinning class, I’m looking forward to incorporating HIIT training in my spring running plan. Experts recommend working up to adding two or three sessions a week. And it’s not enough to just pick up the pace — my spin cycle instructor says you have to get into what he calls “the redline zone,” where you are working so hard you know you can’t keep up that pace for much longer and can only speak one or two words.
Are you planning to give HIIT a try?