Interval training torches calories and builds muscle.
Interval training torches calories and builds muscle. Exercise physiologists William Smith and Keith Burns give tips for making the most of your sprints.
Finding a balance of sprints and recovery is key to a successful interval workout.
After the ﬁrst 15 to 30 seconds of an all-out interval, the body typically enters a semihypoxic state, in which the muscles don’t get enough oxygen, performance starts to decrease, and lactate (which makes you sore after your workout) builds up, William says. To train your body to use oxygen more efficiently, start with 15-second intervals and add 15 seconds each time you exercise until you hit one minute.
Aim for a 1:4 ratio: If your sprint interval is one minute, your recovery walk or jog should be four. Seem like a lot? “It takes that long for the body to prepare for the next push. Otherwise, the following sprint will be compromised,” Keith says. And avoid going too hard when you’re supposed to be recovering. You should be able to say a full sentence William explains. You’re not slacking; you’re letting your body maximise its work periods.
Once you’ve stopped exercising, your body is still busy consuming extra oxygen, rebuilding your muscles, and replenishing its fuel stores – all of which burn calories. To facilitate the process, walk STEP for a few minutes, stretch your muscles, and stand up and move around every 30 to 60 minutes for the next several hours. “This allows your muscles to recover properly,” William says.