What Is High Intensity Interval Training?
High intensity interval training, or HIIT, involves alternating between short bursts of maximum or near maximum effort and periods of active rest. For example you might sprint for 30 seconds and then walk for a minute. HIIT can be done with a wide variety of exercises, including bodyweight exercises or even weights, but sprinting is probably the best.
The Benefits Of HIIT
HIIT burns calories much faster than other forms of exercise. And just as importantly, you continue to burn calories for many hours after your workout. This effect is known as ‘afterburn’ or EPOC (excess post-exercise oxygen consumption), and it does not happen to any great extent with other less intense forms of exercise such as jogging.
But besides being the best cardio for weight loss, HIIT has other benefits too. It increases your output of growth hormone, which helps burn additional fat whilst preserving muscle. And it also gets you fit much faster than other forms of exercise too. In fact both your anaerobic and your aerobic fitness are greatly improved with this type of exercise.
Apart from all this, HIIT helps lower blood pressure, bad (LDL) cholesterol and triglycerides. It increases good (HDL) cholesterol and improves insulin sensitivity. It also improves heart and lung function as well as strengthening muscles and bones. So it will greatly reduce your risk of heart disease, stroke, type 2 diabetes and many other degenerative diseases.
A Sample HIIT Workout Routine
Jog for 5 mins to warm up.
Sprint for 30 seconds at close to maximum effort.
Walk for 60 seconds at a slow to moderate pace.
Repeat 3 – 8 times depending on how fit you are.
Walk slowly for a couple of minutes to cool down.
Total time: 10 – 18 mins.
Variations On The Theme
You can do HIIT in a number of different ways. For instance you might want to do shorter sprints of maximum effort, or longer sprints of somewhat lower intensity. If you are a beginner you could take longer recovery periods, or if you are more advanced you could shorten the recovery periods. Or you could simply vary the times and distances to suit yourself.
For example, The Tabata Protocol involves exerting maximum effort for 20 seconds, followed by just 10 seconds of active rest. This is repeated 8 times, for a total workout time of just 4 minutes (plus your warm-up). But this will be the most grueling 4 minutes of your life. Tabata is an advanced strategy to use if you are already very fit.
Alternatively, Fartlek training is far more flexible. Here you alternate periods of high intensity, moderate intensity and lower intensity as and when you feel like it. So you let your body dictate when you sprint and for how long. This is excellent if you like a good degree of flexibility, but if this sort of routine tends to make you a bit lazy, you may find a more usual style of HIIT workout will suit you better.
How To Accelerate Your Fat Burning Still Further
HIIT releases a lot of free fatty acids into the bloodstream, whereas with steady state cardio such as jogging it takes at least 20 minutes before any fatty acids are released at all. However jogging is excellent for burning fatty acids that are already in the bloodstream.
So to further boost your fat burning results simply follow your HIIT workout with 15 – 30 minutes of low intensity steady state cardio. This will burn off all those fatty acids in your bloodstream, as well as helping to continue the afterburn effect for longer too.
There’s really just one downside to HIIT – it can be difficult to recover from, especially if you overdo it. So never do a HIIT workout more than three times per week, and twice per week might be better for most people. In fact doing it just once per week can give some great results.
So the very best cardio for weight loss is to do a HIIT workout routine like the one described here, and follow it with a short session of lower intensity steady state cardio. Combined with a sensible diet this will give you that lean look in far less time than anything else.