Invented by Japanese professor Izumi Tabata, this is a form of high-intensity interval training. It involves 20 seconds of exercising as hard as you can, followed by 10 seconds of rest.
The cycle is repeated eight times meaning you’re done in just four minutes. Don’t be swayed by that short time though, this is a tough workout. It was developed by the Prof after clinical trials with the Japanese Olympic speed-skating team found it was a super-effective way to improve aerobic and anaerobic fitness.