Get on yer bike and pedal as hard and fast as you can for eight seconds, then slowly for 12 seconds, and repeat for 20 minutes. According to researchers, doing this three times a week will have the same weight loss effect as five hours of jogging. Fast sprinting causes the body to release high levels of a specific group of hormones, called catecholamines, which drive the release of fat, especially abdominal and visceral fat, from fat stores so it can be burned by working muscles. ‘’We don’t know why, but moving limbs very fast 
generates high levels of catecholamine,’’ Dr Boutcher, whose findings are published in the Journal of Obesity, said.
Source: Journal of Obesity