Tip #6: How intensely should you exercise?

You may be familiar with the following exercise guidelines for adults from the U.S. Department of Health and Human Services: ” Adults should do at least 150 minutes (2 hours and 30 minutes) to 300 minutes (5 hours) a week of moderate-intensity, or 75 minutes (1 hour and 15 minutes) to 150 minutes (2 hours and 30 minutes) a week of vigorous-intensity aerobic physical activity, or an equivalent combination of moderate- and vigorous-intensity aerobic activity. Preferably, aerobic activity should be spread throughout the week.”

Great advice if you know the difference between “moderate-intensity” and “vigorous-intensity activity.” The following chart gives you two methods to judge whether or not your physical activity is intense enough.

The first method, Rate of Perceived Exertion (RPE), is a subjective measure based on your ease or difficulty speaking while exercising. The second method, percentage of maximum heart rate (MHR), requires a heart rate monitor, like a bike computer or a sports watch with a heart rate function, and a calculation of your maximum heart rate and zones with a VO2max test, which is only recommended if you intend to compete at some point in the future.

Whatever method you use, the common denominator is that you should be sweating during your workout. Otherwise, you’re wasting your time and kidding yourself about your fitness if all your workouts are “light” or “very light” intensity.

Knowing my heart rate zones precisely was a prerequisite for my coach to construct my training plans when I started racing time trials. The only way to accurately determine these zones is with a VO2max test. This test requires a laboratory setting and a specialized computer called a metabolic analyzer. You ride an exercise bike while the resistance is steadily increased every one to two minutes until you are too exhausted to continue. You are wearing a face mask hooked up to the analyzer. I’ve completed five VO2max tests to date: 2003, 2005, 2010, and two in 2017. My maximum heart rate for these 14-16 minute tests ranged between 140 and 166 beats per minute (bpm).

When racing, my lactate threshold, the maximal effort or intensity that an athlete can maintain for an extended period of time with little or no increase in lactate in the blood, has been confirmed at roughly 130 bpm, or around 90 percent of my MHR. Calculating the rest of my heart rate zones is simply a matter of a percentage of MHR. When I train, I know exactly where my heart rate needs to be to achieve a workout at a recovery intensity, moderate intensity, or high intensity, depending on that week’s plan.

If you have any questions about living an active lifestyle or about your cycling goals, training, racing, or gear, I’d like to hear from you. I may address your questions in a future tip. Just drop me a note.