Are you bored of running on the treadmill for 30-50 minutes at a time? Do you feel like you could be doing more to better your health and physique? You may want to try out HIIT, or high intensity interval training. HIIT is becoming an increasingly popular exercise regimen not only as a fad, but also in scientific literature. I’m here to tell you what you need to know about HIIT: what’s actually true and what’s not according to the literature.
First, it is important to note that if you are prescribed an appropriate HIIT routine, you can experience all the same benefits as traditional steady-state activities in a much more time-efficient manner.
HIIT is generally known as exercise involving several short high intensity bouts with longer rest intervals in between. There are four main variables you can play with: work interval intensity, work interval length, rest interval intensity, and rest interval length. Depending on what you do with these variables, the adaptations you experience will be different.
For example, you could do ten 20-second all-out sprints on a track or a bike with 100-second walking rests in between. This very high intensity will challenge your muscles, similar to weight training. Your anaerobic system and lactate threshold (that point at which you feel that burning sensation in your muscles during intense exercise) will be worked and pushed so that, after a few weeks, you should be able to sprint faster. You would likely see muscular gains in your calves and thighs and glutes.
You could also do ten 1-minute work bouts at an intensity you could keep up for roughly a few minutes (at about 95% the speed your maximum heart rate would be at) interspersed with 1-minute rest intervals. This protocol would again challenge your anaerobic system to a strong degree, but you will still be quite reliant on your aerobic system as well (what you typically use during a long steady-state run). You may see muscular gains here to a lesser degree than all-out sprints, but your cardiovascular system will be challenged more. Here you would see a good mix of muscular gains and improvements in your aerobic and cardiovascular system, improving your breathing capacity during exercise and the time to exhaustion.
Lastly, you could try 4-minute work intervals interspersed with 3-minute rest intervals. Here, you are working at a high intensity, but below that lactate threshold so that you can hold it for several minutes (though if you could hold that pace for 20 minutes or more, that’s too light). The rest intervals here are more intense than the previous protocols and require some effort, though are lighter than the work intervals. This protocol primarily challenges your aerobic system, but gets you closer to that lactate threshold than regular steady-state exercise. Getting that extra dose of high intensity activity is important and associated with decreases in risks for many chronic diseases.
Of course, you can come up with your own combination of work and rest intensity and length variables. The systems you challenge during exercise change as a continuum according to intensity, there is no absolute cut off. And of course, the key to exercise is to enjoy it (otherwise, how are you going to make it a habit?). If you’re looking to try something new, try a variation of one of the protocols listed above. You may be surprised that 20 minutes of alternating high intensity activity can be more fun than 40 min of steady-state and will still help you reach your goals.
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UMass Campus Recreation
By,
Nicholas Remillard
UMass Personal Trainer