Upcoming events

Why doesn’t exercise intensity count?

I don’t think it’s fair that the 15 minutes I spend running aren’t weighted differently than the 15 minutes someone else spends walking. Why doesn’t exercise intensity count?

We used an intensity measure during the getfit pilot program that was completed several years before the first Institute-wide challenge and involved approximately 100 MIT Medical employees. Participants in the pilot program used a formula to compute “activity scores” based on exercise duration and an estimate of average intensities for a long list of potential exercise activities. Unfortunately, this worked poorly in practice, because participants often came up with activities not included on the original list of activities, disagreed with the assigned intensity values, or made mathematical errors in computing their scores. Even with a relatively small number of participants, a large amount of administrative time was required to resolve scoring problems.

When the program was expanded to the entire Institute, we considered other ways to incorporate exercise intensity, such as requiring participants to measure heart rate or pulse. However, none of these methods seemed practical to use in a program with several thousand participants, many of whom would be beginning exercisers. And with such a large number of participants, we needed an easily quantifiable measurement criterion that didn’t require subjective judgments beyond the capabilities of our automated tracking system. We decided “minutes exercised” would work well with our online database, and by using our definition of “exercise” (See “What counts as exercise?“), it would allow beginning exercisers to participate alongside marathon runners and other elite athletes.

Getfit is all about individuals challenging themselves to become more fit. For that reason, exercise intensity should matter to each individual participant, and we trust that each participant is making an effort to exercise at a level of intensity appropriate to his or her physical capabilities. For many people, this is something that will change during the course of the program. A number of beginning exercisers tell us, for example, that during the fourth or fifth week of the program, they need to walk much farther to earn the same number of minutes they would have earned in half the distance during the first week or two.

« go back