Dr. John Day, Cardiologist

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60 vs 20 Minute Cardio Workout: Which is Best?

Do you have 60 minutes to spare each day for exercise?  If you are like most of my patients, the answer is “no.”  Can you get all the benefit of exercising for an hour in just 20 minutes?  In the 60 vs 20 minute cardio workout, which is best?

Michael’s Experience

Michael was my typical hard charging CEO patient.  He routinely put in 60-hour workweeks and his health suffered.  For years, I encouraged him to start exercising.  Unfortunately, I always got the same response.

“Doc, I just don’t have time to exercise.”

Our breakthrough finally came when I talked with him about compressing a workout into just a few minutes several times a week.

“Will exercising such a short time even do any good?” he asked.

“All the benefits of a long exercise session in just a fraction of the time,” I said.

“Count me in,” he said.

60 vs 20 Minute Cardio Study

Here is the study I recently shared with Michael.

To answer the 60 vs 20 minute cardio workout question, University of Alabama researchers recruited 28 overweight people who weren’t used to exercising.  For six weeks, these people were randomly assigned to one of two workout groups.

The first group was the usual moderate intensity exercise group.  These people pedaled 60 minutes a day, five days a week, on a stationary bicycle.

In contrast, the second group was the high intensity exercise group.  These people pedaled all out in four, 30-second sprints, mixed with cool down periods, for a total of 20 minutes on three days of the week.  Even though the high intensity group really only exercised six minutes a week (two minutes of sprinting on three days), the total time investment with the warm up and cool down periods was one hour.

Did 60 minutes of cardio beat out 20 minutes?

Basically, the study was a draw.  There was no statistical difference between a 60 vs 20 minute cardio strategy.  After 6 weeks, both groups saw roughly the same benefit with regards to weight loss, lower blood pressure, better cholesterol numbers, and improved insulin sensitivity.

The only benefit of the 60 minutes group, was that they were in slightly better shape at the end of the study.  However, this finding is an outlier, as most other studies have shown no difference.

The key message is that you can get all the benefit of exercising in just a fraction of the time.

How To Do High Intensity Exercise

Here is how you could apply this high intensity exercise protocol in your own life.  First, pick your favorite exercise.  It could be walking, cycling, hiking, or just about anything.

For your 20-minute cardio workout, start by warming up for four minutes.  If walking is your exercise of choice, walk at your normal pace for four minutes.

After warming up, you will do a total of four, 30-second sprints, interspersed with a two to three minute cool down period.  In the walking example, your “sprints” could be walking as fast as you can up a hill for 30 seconds.  Your cool down periods would be walking at your normal pace on a flat surface.

To know that you are going all out with your sprints, your heart rate should hit 85% of your maximally predicted heart rate.  This was the criteria that they used in this study.  To calculate this number, your maximally predicted heart rate is 220 minus your age.

Thus, if you are 40 years old, your maximally predicted heart rate is 180 (220 minus 40).  Eighty-five percent of 180 is a target heart rate of 153 beats per minute.

Share Your Experience

High intensity or interval training sounds simple, right?  Give it a try and let me know how it goes in the comment section below.  If you have a question, I will answer those in the comment section as well.

Of course, if you are not used to exercising or suffer from any medical conditions, please check with your doctor first before exercising.