I’ve been doing a lot of interval training during my current weight loss cycle. Initially I was doing 100m sprints but that became less appealing as the weather got colder.
I watched Dr Michael Mosley‘s “The Truth about Exercise” and it reminded me that sprints can also be done indoors. The High Intensity Interval Training (HIIT) plan that Dr Mosley examines in the documentary comprises of 3 x 20s sprints on an exercise bike with a minute of active rest between sets, so I decided to try it out on the spin bikes at my gym.
The theory behind HIIT is that short, intense exercise employs a higher percentage of muscle tissue and depletes their glycogen stores. The exhausted muscles create an “energy sink” that triggers the body to release its stored fat to replenish the spent glycogen in the muscles.
The burn is unbelievable. By the third sprint my muscles are screaming for mercy, I’m out of breath and exhausted, and my legs are wobbly to the point that walking can be a challenge. And yet I don’t break a sweat.
The total workout is only about 5 minutes, which seems ridiculously inadequate compared to the oft-recommended “20-minutes of cardio three times a week” dogma but I feel that it has been very effective. My bodyfat has decreased noticeably, and my VO2 max has improved to the point that I can do five sprints instead of three on my non-lifting days.
Besides, who can’t spare 5 minutes a few times a week?