I get that question a lot and will briefly explain the principle. In a nutshell, we have two main sources of energy in our bodies that are used for exercise. Energy stored in the form of fat and energy stored in our muscles in the form of muscle glycogen. The higher your exercise intensity, the more calories you will burn and of those calories burned, most of those calories will be burned from muscle glycogen stores where fewer will be burned off from your fat stores…
So why would I work out at a high intensity if most of the calories are going to be burned from muscle glycogen stores?
You will burn more total calories when you work out at a high intensity versus a low intensity. For instance, if you ran for an hour you might burn 700 calories. Of those 700 calories, 40% may burn from your fat stores while about 60% will burn from your muscle glycogen stores. On the other hand, if you walk for an hour that calculation reverses where approximately 60% of your calories may burn from your fat stores and 40% may burn from your muscle glycogen stores. But your total calories burned while going for an hour-long leisurely walk may only amount to 100 total calories. The catch here is 40% of 700 (an hour running at a relatively high intensity) is more than 60% of 100. (An hour walking leisurely).
So what sort of intensity should you work out in?
That depends upon your current fitness level, how often you exercise, how much time you have to exercise, what your fitness goals are and the state of your health. Some people may not be healthy enough to work out at a high intensity. Or if they don’t have a history of regular current exercise then exercising the first day at a high intensity could be a poor decision as that could cause a lot of muscular discomfort for several days until the pain of the lactic acid in the muscles goes away.
My advice is to take it slowly and do a little bit each day, listen to your Healthy Body and try to vary your exercises. As you become more fit, increase your intensity. Working out for a long duration at a low intensity one day and a short duration at a high intensity the next day offers the best of both worlds. More importantly, just keep moving every day.
Until next time, keep…
Fit ‘N’ Well.
