I enjoy exercise. Especially if I notice that it makes a difference in my waistline. You know, after four babies, I need something effective. But not all exercise is effective.
A few years ago, I began to cull some evidence that the slow and steady workouts I had been spending my time on were not as efficient as a shorter interval workout. Efficient in terms of fat burning and muscle toning. I also read an article that described how the long, slow, steady workouts were not as beneficial in keeping our heart muscle functioning at top notch.
The research showed that during a slow and steady workout, such as a walk or a jog or a session on the elliptical machine, our metabolisms will start to "preserve" energy by slowing down. This is the exact opposite of what we are trying to achieve. We want to burn more calories and more fat, not keep it. But, in a long, slow workout, our bodies prepare for a marathon and keep the energy for what might come. I guess they just don't understand that we will stop after 45 minutes or so.
However, when we put our body through interval training - where we mix short bursts of maximum exertion with periods of active rest - we keep burning fat and calories at a peak rate. This type of interval training also keeps our heart muscle working at its peak potential.
I have used this type of training for a few years. It has been a good use of my time. Instead of 45 minutes, I exercise 25 and get even better results. I have even seen interval training exercise dvds put out by some of the biggest names in exercise. These workouts are usually 20 minutes plus the warm up and cool down. Sounds good, huh?
If you don't use exercise equipment or dvds, you can still work this exercise theory into your running or your walking. You can time yourself for two minute bursts of maximum effort and equal active rest times to let your heart settle back into a steady rhythm. The goal would be to work up to three minute fast intervals with two minute rests. Just walk or jog at a slower pace during your recovery time.
You could even change things up by alternating fast and slow songs on an ipod. It doesn't have to be meticulously methodical... the key is just to vary up your exercise intensity. Keep your body guessing. It will do your metabolism good.