It seems like one of the major reasons people don't like to work out is the amount of time it takes to do so. However, a study in the Journal of Physiology suggests you might be able to get all the exercise you need in just 20 minutes if you're willing to work at it.
We've talked briefly about interval training before, but this is one of the first studies to dig into if it actually works as a replacement for the usual recommendation of 30 minutes of continuous exercise. The idea is simple. You workout for one minute with strenuous activity and push your heart rate to about 90 per cent of its maximum rate.
You can get a rough estimate of your heart rate by subtracting your age from 220. After the minute is up, you slow down and recover for one minute. You then repeat this 10 times for a total of 20 minutes (or 10 minutes of actual exercise). You can use this for running, cycling, swimming or any number of cardiovascular workouts.
If you're crunched for time and can't get that full 30 minutes in, this is a great way to shorten the duration and still get in shape.
[Via Journal of Physiology]