A good friend asked for my opinion the other day about two exercise routines. She was in a debate with her co-worker about which one was more “efficient.”

When speaking about exercise, efficiency can be misleading. When we think about things that are efficient, we think about something that’s smooth, streamlined and easy. Typically in life, more efficiency is considered better.

However, the opposite may be true when it comes to exercise and energy expenditure. When your body is moving efficiently, it doesn’t have to work very hard. If you decide to go for a nice walk or push around the block, chances are your body is pretty used to that motion and can meet the demand without expending much energy. But this workout that is “efficient” to perform may not be the most efficient at giving you the wonderful benefits of exercise.

Let’s consider a high-intensity interval workout (my fave!). It’s not very efficient in the sense that your body has work at just about max capacity and then switch to a low intensity phase, then get itself back to max again and then rest again…etc. It’s definitely not what you would consider smooth, streamlined, and easy! But it’s the very inefficiency of high intensity intervals that make them so efficient! Efficient in the sense that you can get your heart rate up much higher, burn significantly more calories, get more benefits in a much shorter length of time.

Of course there are times when it is much more beneficial to be efficient in the sense that you want the best performance from your body with the least amount of effort/energy expenditure (e.g., during athletic competition). But that doesn’t mean your training should be that way. And longer, slower aerobic exercise has its benefits as well. But if you’re looking for the most bang for your buck in terms of cardiovascular benefits and calorie expenditure, an inefficient workout is much more efficient!

Example of one of my HIIT (high intensity interval training) bike workouts (I usually do this on a spin bike so resistance is estimated):

Minute 1-5: warm-up; cycling at about 30-40% max speed
Minute 5-5:30: increase resistance to 85% max; pedal at max speed
Minute 5:30-6:00: no resistance; pedal comfortably
Minute 6:00-6:30: 85% max resistance; max pedal speed
Minute 6:30-7:00: no resistance; pedal comfortable
Repeat 30 seconds high intensity with 30 seconds recovery until 10 minutes is reached (a total of 5 intervals).
Minute 9:30-15:00: pedal comfortably
Minute 15: Repeat if you can handle it! I usually try to stand up and pedal during the high-intensity intervals the second time around to work my core muscles.

You can do this on a treadmill, arm ergometer, jumping rope, outside running between mailboxes, etc. Start by simply increasing something (speed, resistance, etc.) for 15 seconds and then bringing it back to a comfortable pace for the rest of the minute. Try to do this for 10 minutes total. Work on adding more intervals to increase your total time to 20. Then start lengthening your high-intensity intervals and decreasing your rest time. How wonderfully, inefficiently efficient!