This blog post about how to get skinny legs by using HIIT will teach you how to tailor your HIIT to make it a fat burning activity and assist you in getting those skinny legs!
You may have remembered from my previous blog post on cardio that low to moderate intensity cardio is a fat burning activity, whereas HIIT and weights typically are not.
HIIT and weights are an anaerobic activity, which means your body uses glycogen (carbs) as the main fuel source, not fat. Cardio is an aerobic activity, which means your body uses glycogen (carbs) and fat as the main fuel source. Note that HIIT and weights typically do not burn fat.
- Cardio (longer duration steady state exercise) –> aerobic –> burns fat
- HIIT (short bursts of high intensity exercise) –> anaerobic –> burns glucose
So why do we still need to do HIIT then?
HIIT increases general cardiovascular fitness and also increases your anaerobic threshold. This means that during exercise your body will remain in the aerobic (fat burning) zone for longer, before switching to the anaerobic pathway.
The result? You can exercise for longer and at a higher intensity and still burn fat.
How to do HIIT effectively for fat burning
My favourite example here is interval running. If you are sprinting for 15-30 seconds at your absolute fastest speed, with a 30-second rest, your body is using the anaerobic pathway and is using predominantly glycogen. This may also contribute to bulkiness in your legs.
However, if you are running at a fast (not maximum) speed for 90 seconds to 2 minutes, your body will most likely remain in the aerobic zone for the majority of the time, hence burning fat. The fitter you are, the longer your body will remain in this aerobic zone before switching to anaerobic, i.e. burning more fat!
How to get skinny legs using HIIT – Fat burning HIIT
This is my favourite type of HIIT. It is not a proper sprint, more of a fast-paced interval run. Make sure you do this on a flat surface. Hill sprints are great but will build more muscle.
- 5-minute warm-up walk at 6-7km/hr
- 400m run at around 14km/hr (takes about 1 min 50 secs)
- 60-second walk at 6km/hr
- Repeat as many times as you can. If you’re a beginner, aim for 3-5 rounds. If you’re advanced, aim for 8-10 rounds.
- 15 minute cool down walk at 6-7km/hr
NOTE: You do not have to do your 400m run at 14km/hr. However, it must be at a pace that is fast and quite difficult for you to maintain for 2 minutes. After the 2 minutes, you should be in desperate need of a rest. Choose a pace that suits you best.
You can apply this same principle to other forms of gym equipment such as the bike or cross trainer (but remember running is best for learning legs).
Exercise at a medium to high intensity for 90 seconds to 2 minutes and then have a rest or reduce the intensity for 60 seconds. I recommend a 60-second break, but if you need 90 seconds, this is OK. Repeat as many times as you can.
This does not need to be done at the gym either. You could run or cycle outside rather than on the treadmill or bike.
If you would like a more specific workout and nutrition program to target fat loss on your legs and to build lean muscle without getting bulky, check out my ebooks. Each ebook contains an 8-week workout and nutrition program, and there is a separate ebook for each of the three body types. Click here to find out more about my ebooks.
PS read this blog post for a body weight HIIT circuit that won’t bulk up your legs.