Science Questions with Surprising Answers
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Dr. Christopher S. Baird

How long do you have to exercise for it to count?

Category: Health      Published: September 16, 2013

By: Christopher S. Baird, author of The Top 50 Science Questions with Surprising Answers and Associate Professor of Physics at West Texas A&M University

family raking leaves
Public Domain Image, source: HHS.

Exercise starts to "count" the second you start to exercise. By the word "count", I assume we mean that the exercise is making you healthier. Every second of physical exertion makes you healthier, no matter what the activity is, or how long you have been doing it. It's not like the first twenty minutes of a run accomplish nothing and your body turns on once you hit the twenty-first minute of your run. A person who runs for ten minutes a day will generally be healthier than a person not running at all. Athletic trainers often recommend you exercise for at least a half hour in each workout. Such a recommendation does not imply that a twenty minute workout is useless and has zero health benefits. Rather, such recommendations are made in order to present a doable goal that brings significant health benefits. The situation is similar to practicing a musical instrument. Practicing the piano for only 10 minutes a day is not useless. But practicing the piano for 30 or even 60 minutes a day will accomplish a lot more.

For those of us who aren't seriously training, but instead just want to exercise for the general health benefits, consistently exercising a few times every week is far more important than reaching some magical number of minutes during a given workout. Many people have a hard time making the time commitment of 30 minutes exercise each day and end up skipping most of their workouts, thinking that any workout less than 30 minutes long is a total waste. In reality, every minute of exercise is beneficial. It is far more effective for those who are out of shape to focus on consistency and living a generally active lifestyle than to worry about reaching a certain total number of minutes of continuous intense exercise.

Furthermore, you don't have to go to the gym or pound pavement like a competitive athlete for an activity to count as exercise and benefit your health. Vigorous gardening, yard work, sight-seeing on foot, climbing stairs, hiking, walking, and throwing a ball around with the kids all count as exercise and promote your health. William Haskell of the Stanford Center for Research in Disease Prevention published,

"During the last decade a number of epidemiological or observational studies have been published demonstrating a strong inverse association between level of activity or physical fitness and cardiovascular or all-cause mortality, the incidence of adult-onset or Type II diabetes mellitus, hypertension, and site-specific cancers. In many of these studies, the physical activity associated with the more favorable health outcome has been of light to moderate intensity, appears to have been performed on a more intermittent rather than continuous basis, and includes activities such as walking, stair climbing, gardening, and household chores more frequently than conditioning exercises such as jogging, cycling, and playing tennis... a person does not need to perform a bout of ‘continuous exercise for 20 minutes or longer' (1990 ACSM guidelines) to achieve health benefits. Instead, it is proposed that performance of a whole serious of short bouts of activity spread throughout the day, if they total 30 min or longer, will provide significant health benefits."

Topics: exercise, training, work out, yard work