I used to be a competitive long distance runner. Day in and day out I’d run mile upon mile, training for the next big race. Some days it meant running a six or seven mile loop that included several (seemingly endless) hills. Other days, I warmed up for a few miles then hit the track for sprints. Run 400 meters. Walk 100 meters. Run another 400 meters. Walk 100...you get the idea. This interval training on the track, although not representative of any race I would run, primed my body and helped me stay in shape—and boy was it a tough workout!|
Runners and cyclists have utilized interval training for decades. However, exercisers at many different fitness levels can benefit from this type of workout—just adjust it to fit your specific workout needs. Since interval training can be demanding, you don’t need to do it every day. My track and cross country teams trained with intervals twice a week, and focused on other cardio (longer distances) on the remaining days.
Why do an interval workout?
If you’re stuck in a workout rut, intervals can be a new and interesting way to get motivated and in shape. You’ll strengthen your heart, and future workouts will feel easier. Like any workout, it will help burn fat and calories, while also building endurance.
Plus, with interval training the possibilities are endless! No matter what mode of exercise you choose (treadmill, outdoor walking or running, swimming, elliptical, cycling), every workout can be different and the variety within each session keeps things fresh and fun. If you are sick of walking on the treadmill for an hour each day, adding intervals can jumpstart your body out of its low-intensity cardio rut.
The premise of interval training is simple: When you vary your effort by mixing periods of high and low intensities during your workout, your fitness will improve faster and more dramatically—and your workouts will be less boring. During your session, you’ll alternate between shorter, high-intensity intervals and longer, lower-intensity recovery periods. The high-intensity intervals can be "anaerobic" (where you are working as hard as you can, and your heart rate is usually over 85% of your estimated maximum), or simply more intense, like in the 75-85% range, which is still “aerobic.”
You'll know when you’ve reach an anaerobic intensity because you'll start feeling a burn in your working muscles. Adding some anaerobic intervals to your workouts will usually give you better results. But since they are more demanding, anaerobic intervals should be shorter and accompanied by longer recovery intervals. As your fitness level improves, both the length of the high-intensity intervals, and the amount of work you can handle during them, will increase.