The benefits of short, high-intensity training sessions are all about your post-recovery state. If you're working harder you're going to have a slightly elevated heart and metabolic rate, meaning you're burning more calories over the recovery period as well as when you're actually training.
But how much of a payoff does HIIT really offer over traditional, steady-state cardio? Some studies have shown that HIIT burns up to nine times more fat than traditional cardiovascular exercise and keeps your metabolism elevated for more than 24 hours afterwards. This means you are going to keep burning calories long after you have finished exercising.
HIIT workouts do not have any magic formula and can be done on treadmills, ellipticals, bikes, as part of a circuit, etc. Just as long as you put forth maximum effort for a short period of time (30 second to 120 seconds) and allow yourself a recovery period (again for 30 seconds to 120 seconds), you have created a HIIT workout! My favorite style is 60 seconds on and 60 seconds off with a warm up and cool down at the beginning and end.
In case you were wondering, running at 6.0 is a 10 minute mile, running at 7.5 is an 8 minute mile, and running at 8.0 is a 7 minute and 30 second mile.
Sprints….the exercise I love to hate and hate to love. I try to get these in at least once a week as they are an amazing exercise that targets your butt and legs in a very short amount of time. This high intensity interval training (HIIT) focuses in on short bursts of very intense activity with a less intense "rest period" between. I find it much more beneficial to not take a complete rest and rather keep my body moving between the intense periods, as this prevents cramping and your muscles from tensing up. 20 minutes of this type of exercise is more beneficial than an hour or more of steady state cardio in more ways than one:
– Kick starts your bodies repair cycle, therefore you burn more fat
– Increases your metabolism
– Takes very little time … I honestly do no more than 20 minutes of cardio in each session, just focusing in on HIIT specifically each time. That to me is a huge advantage for someone with a busy life. I never want to be someone who is doing 1-2 hours of cardio a day.
– I have found that doing sprints actually improves my steady state running. Back in the day I would have to run, walk, repeat when taking the pupps for runs outside. Now I can go without stopping about ten times as long with so much less huffing and puffing.
– Do a warm-up for five minutes at a reasonably steady pace. This will also be the pace you use as your "rest period"
– At the 5 minute mark chose your "high intensity speed". On average it will take about 15 seconds for the treadmill to work up to that speed once you select it
– Sprint full out for 30 seconds on that speed. At the 45 second mark select your rest speed (again, it will take almost a full 15 seconds to get back down to that)
– Walk at rest speed for a minute
– Repeat x 8
This will take you to 20 minutes. I always suggest a cool down walk at ~3.5 for two minutes. Also try and stretch as this high intensity workout can make you cramp.
Want to make this even more intense – start adding an incline. In order to mimic outside and normal running conditions your treadmill should actually always be set at an incline of 1.0, but why not try an incline of 4.0 while doing these?
See below for an example of the sprints I do every week. Increase or decrease your speed for what feels right for you. But remember by the end of the high intensity period you should be gassed and NEEDING a break. Push yourself, its only 30 seconds of full sprints…you can do it!