Effective Minimum Dose of Exercise

The final group was assigned to interval training, using the most abbreviated workout yet to have shown benefits. Specifically, the volunteers warmed up for two minutes on stationary bicycles, then pedaled as hard as possible for 20 seconds; rode at a very slow pace for two minutes, sprinted all-out again for 20 seconds; recovered with slow riding for another two minutes; pedaled all-out for a final 20 seconds; then cooled down for three minutes. The entire workout lasted 10 minutes, with only one minute of that time being strenuous.

http://mobile.nytimes.com/blogs/well/2016/04/27/1-minute-of-all-out-exercise-may-equal-45-minutes-of-moderate-exertion/

Effective Minimum Dose of Exercise