With Interval Training you’ll burn more calories in less time, you’ll reduce your risk of injury and you’ll be burning calories for the rest of the day! (increased EPOC which means in English because the training is harder your body will spend the rest of the day trying to recover, which takes extra calories)
A good Interval Training program should involve two stages the first being a jogging stage in which your heart rate should be 80-85% of your predicted max heart rate.
The second stage will be where you really put the work in and raise your heart rate up to 86%-90% of your predicted max heart rate. You need to stay in stage two for 30-45 seconds, Then return to stage one.
The length of time that you remain in stage one before again returning to stage two will be dictated by your heart rate, you should not return to stage two until your heart rate has returned to 80-85% of your max (you will need a heart rate monitor to do this) if you find you’re heart rate is not coming down then you need to reduce the speed on the treadmill.
For total workout time you should aim for 20-30 minutes including a warm up.
The different stages of Interval Training are crucial to overload your cardiovascular system which then forces a change, for example during the average gym class you will always (at a maximum) be in stage two and you will quickly plateau which means no more changes. Attend a gym class for a three months and you’ll be lucky if you see one person who loses a significant amount of weight (excluding spinning) If you hadn’t lost at least a stone in 3 months a personal trainer would give you your money back!