…I DO HIIT? WHAT HAPPENS WHEN...
Interval training may now be de rigeur for the busy fat-burner, but these proven tips will give you an even bigger bang for your burpee
01 DO THE WORK
It’s true: if you’re not going hard, you should go home. “For optimum results during your high-intensity interval training (HIIT), you need to work at 90-100% effort for 15-30 seconds,” says sports therapist Barry Sigrist*. “By working anaerobically (without oxygen for fuel) you produce lactic acid, which releases adrenaline, helping to move fat around the body.” With shorter work periods, you won’t fully benefit; go longer and you risk poor form – and turning embarrassingly red.
02 REST ASSURED
To squeeze maximum benefit from your all-out efforts, you need to rest the hell out of those intervals. “The ideal ratio for a 20-minute session is 30 seconds on, 60 seconds off. Resting too long might feel like cheating, but your muscles need time to renew their oxygen and glycogen levels,” says Sigrist. “Too little rest and your body becomes catabolic, breaking down muscle tissue.” You’re not resting because you’re weak: you’re resting because you want to stay strong. So, chill.
03 LEVEL OUT
Of course, not everyone can hit the golden work-rest ratio on first try. As your muscles’ demand for oxygen outstrips supply, your heart rate during rest periods will increase. “You may find your timed rest intervals insufficient to get you back to a level where you can perform at full intensity,” says Sigrist. “Use a heart rate monitor to see exactly when your body is ready to go: 65% of your max heart rate is ideal.”
04 TEST RESULTS
To power your HIIT session, your body taps into muscle glycogen, not your fat stores. This might sound like the opposite of what you’re after, but its weightloss powers are more subtle: “HIIT triggers a release of human growth hormone and testosterone, both of which play a key role in metabolising fat,” says Sigrist. For best results, elicit a peak hormonal response by incorporating multi-planar compound movements (such as burpees) into your session, performing them as fast as you can. Don’t expect to enjoy it.
05 A NEW EPOC
With your workout over, you’ll leave the gym – or park – with your afterburners ignited. “Unlike steady-state cardio, the magic of HIIT takes place after your session. Your body has an ‘oxygen debt’ to repay, and this creates something called excess post-exercise oxygen consumption (EPOC),” says Sigrist. Simply put, you continue burning calories for hours after you stop. You can amplify this effect by staying active, so try to go before work rather than after and then heading home to surf the sofa – tempting as it is.