I don’t know if you’ve heard, but interval training is starting to make it big. But why? I am going to attempt to answer this question the simpleist way I can, even though the answer can be quite complex when you really get into it.
Everyone has three sources of energy: immediate, short term and long term. And the primary energy source for work is called ATP (adenosine triphosphate).
Immediate energy is supplied by a different high energy phosphate called Creatine Phosphate (CP). The CP is able to donate its phosphate to ADP to make ATP, which gives you the energy you need quickly. The problem is, CP storage lasts only about 3 to 5 seconds.
Short term energy comes into play when CP runs out and muscles begin to break down glucose from the muscles glycogen store. Glucose then goes through a process called glycolysis which allows ADP to be converted to ATP again. This makes the muscle able to maintain a high rate of work a little longer. This doesn’t last though because while glycolysis helps make ADP to ATP, it also produces lactic acid which eventually slows the rate of this process and slows you down.
So finally we have the long term energy source! This involves production of ATP from sources like muscle glycogen, blood glucose, and intramuscular fats. This process takes longer because unlike the others it actually requires oxygen. But if lasts longer because of that.
So back to the question…why interval training? Well, when you sprint or do any burst of energy, it doesn’t take you as long to use up those first energy sources. Then once you use those up, you can start using the long-term energy source which uses fats from your muscles. And most people want to use up that fat!
If you’re interested in interval training I would suggest getting a program before just starting out and running as fast as you can then stopping. Your body needs to be training the correct way to prevent injury and maximize results. But, if you are interested, it is a great way to train and get in shape!