An effective method for burning fat when you are doing cardiovascular exercise is to use interval training workouts. This workout incorporates short high-intensity bursts with a lower recovery effort, which keeps the body burning calories long after working out.
Long aerobic workouts have been promoted as the best method to reduce fat, as fatty acid utilization usually occurs after at least 30 minutes of training. HIIT seems somewhat counterintuitive in this regard, but has nonetheless been shown to burn fat more effectively. There may be a number of factors that contribute to this, including an increase in Resting Metabolic Rate.
How fast is fast?
Use the Rate of Perceived Exertion (RPE) method, where 1 is sitting still, at 5 you can still hold a conversation, but with a small degree of difficulty and 10 finds you asking for an oxygen mask, to gauge how hard you are working.
This program starts off with a 90 second break, If you need to rest longer than 90 sec., please do so. It is not unusual for people to start off with one 15 second sprint interval and 3 minutes of rest.
3-5 Min Warm up
6 Sprint Intervals - 30 Seconds each (beginners may want to go 6-7 RPE)
6 Rest Intervals - 90 Seconds each (with a recovery of 3-4 RPE)
5 Min Warm Down
Do the routine 3 times in the week with a rest day in between each workout
Note: You are just trying to get your body used to the intervals, do not go all out the first couple of time, ease into this program. If you start to feel dizzy at any time, you are working too hard for your fitness level at this time – slow down! A good cardio program utilizes both the HIIT and regular, longer (30-45min) cardio. Incorporate both into your workout program.
Variation: As with all training, you should add variety to your interval training as you would with any type of training. You should change it every 4 to 6 weeks in order to keep it fresh. Some good ways to add variety is to change the times, or perform your training on a bike, stairs, hills, stationary bike, Stairmaster etc. If you want to make it harder, go outside and find some hills to sprint up, or add an incline to your jog on the treadmill.
As you progress, you can either increase the duration of your high intensity interval, reduce the recovery time interval, or do both.