Interval Training: More Bang For Your Buck

12/10/2011 11:30 am ET | Updated Feb 09, 2012
  • Estelle Underwood Certified Personal Trainer, Owner of Bodyworks for Total Health, Creator of the BodyWorksBand

If you're one of those exercisers who feel like you have reached a plateau in your workouts, it's time for you to consider "interval training." The good news about this is that by putting a little more effort into a shorter workout time, you will actually burn more calories -- just by increasing intensity for a few short segments of time.

Interval training is a type of "anaerobic" exercise training in which you alternate bursts of high intensity activity -- or "work" periods -- with intervals of lighter activity, known as "rest and recovery" periods. So just when you think you can't go on, you get to slow down and take it easy!

"Anaerobic" exercise is defined as exercising at a rate in which the blood stream cannot supply oxygen to muscles fast enough. Basically, it's exercise without oxygen. The muscle still receives oxygen, just an insufficient supply to meet the demands of the activity in order to sustain it for long periods of time. Your anaerobic capacity -- known as "anaerobic threshold" -- can be improved with training. Interval training is a great way to achieve this.

What Can Interval Training Do For You?

According to a study done by Jason Talanian, a PhD student at the University of Guelph (recently published in the Journal of Applied Physiology), interval training burns fat and improves cardiovascular fitness more quickly than constant moderate or low-intensity workouts.

Whether you're a beginning exerciser or a hard-core athlete, this type of training will pump up your workout routine big time! In addition to burning more calories quicker, you will be able to exercise longer or with more intensity because your cardiovascular fitness (aerobic capacity) will greatly improve. So you will burn more calories in less time than you will doing a traditional workout.

Another reason I love incorporating interval training into my weekly workouts -- and those of my clients -- is because it keeps the boredom factor at bay. So here you go, all you people who complain about boredom when walking or cycling for long periods of time. You won't have a chance to get bored with this type of training! During the course of the interval workout, you have to pay attention because every few minutes you're changing the intensity of the workout -- you're constantly doing something different. Before you know it, you're done! And for some of you, being "done" with exercise is the best part, right?

How Is Interval Training Done?

Alright, so how does one go about "interval training"? Well, the great thing is that you don't need any special or different equipment -- you can simply modify your current exercise program -- whatever that may be. For example, if you walk outdoors or on a treadmill, you can periodically incorporate short bursts of jogging or faster walking. Another suggestion is to incline your treadmill for the intense periods. Or on a stationary cycle, you would increase the intensity for the "work" intervals by either increasing the resistance or the rpms.

You can decide what your time ratios will be. When you're just starting out, it might be wise to keep your "work" intervals at 30 seconds, with a two minute rest/recovery interval. So you would just keep alternating that two minute, 30 second ratio -- two minutes of rest followed by 30 seconds of high-intensity work. Don't get too excited -- recovery doesn't mean you stop to rest. It simply means you back off and work in a normal training zone where your heart rate is approximately 65 to 85 percent of maximum heart rate.* This means you are training "aerobically" -- or with oxygen. Then, when it's time for that 30-second burst of energy, you take it up to 95 percent of maximum heart rate so that you are training "anaerobically," or without oxygen -- pushing it to the limit.

After two to three weeks of doing this method of training, you can change the time ratio to make it more challenging, like two minutes of rest/recovery to one minute of work, or even a 1:1 ratio. There are many different ways to set this up. In terms of time duration, there's a lot of flexibility here. If you're a seasoned exerciser, it's fine to do these intervals for up to an hour, but the beauty of this is that you'll still benefit from it greatly if you just do it for 20 minutes. On my interval training days, I usually train for 20 to 30 minutes, depending on how much time I have. Since I only have an hour to train my clients, if we're doing interval training, we do it for 20 minutes before we do weight training. Believe me, they are worked out and sweating by the time those 20 minutes are over!

How Often Can Interval Training Be Done?

Because of the intensity of interval training, I recommend doing it only a couple times per week -- once if you're just starting out. Be sure to leave at least three days in between for recovery and growth. You can increase your frequency after about two to six weeks of training. Just to clarify, I am NOT saying that this is all the exercise you need to do! (I know, you were getting really excited there for minute, weren't you?) On the days that you're not interval training, you will continue to exercise in the traditional ways. Just replace one or two of your cardiovascular workouts per week with interval training.

It's also important to note that when you do this type of training, you must warm up at a moderate pace for three to five minutes, and then cool down at the end of your intervals for at least three to five minutes. This is important for injury prevention and recovery.

The information about interval training is powerful. Research confirms that these intense bouts of exercise improve fitness and burn fat similarly to traditional aerobic training in much less time! Studies have determined that one hour per week of interval training (that doesn't have to be one continuous hour) is equivalent to five hours per week of traditional training. Just think of the increased calories alone that can be burned in a fraction of the time you normally would have to spend.

So there you go... another tool to help you find time to exercise while getting over that plateau you may have reached and increasing the results of your efforts. Try interval training -- I know you it will give you the bump up that you need!

*Maximum heart rate can be approximately calculated by subtracting your age from 220.