“If there is any deficiency in food or exercise, the body will fall sick.” Hippocrates Circa 450 BC
The human body is made to move. Whether through exercise or general physical activity, our bodies need movement to stay healthy. Anyone who’s had an arm or leg in a cast can tell you how it results in muscle wasting and lack of movement around the joints. And we know long-term inactivity such as sitting, leads to weakness and greater chances for disease and early death. But how much exercise do we really need to be healthy and prevent disease?
Exercise Guidelines Galore
When it comes to recommending exercise and physical activity, there’s no shortage of guidelines out there. Fortunately, most of them are similar recommending a minimum of 150 minutes or more of moderate to vigorous activity per week. Additionally, people are encouraged to increase to 300 minutes per week for additional benefits.
Of importance is the emphasis on moderate to vigorous activities. These activities increase your heart rate and breathing. What type of activity that means to you depends on your fitness. For some people a brisk walk may be sufficient. For others, it may mean jogging or running. An easy guide is to follow the SING-TALK-GASP test. Your activity should be vigorous enough so you can’t sing but doesn’t leave you gasping.
This also means activities that don’t meet this threshold don’t count toward the weekly target. Examples include activities of daily living (or non-exercise activity thermogenesis, NEAT). However, there’s still a role for NEAT activities in your health.
While the guidelines translate to roughly 20-30 minutes per day, there isn’t a requirement to spread the 150 minutes out evenly over the week. You can do an hour one day and do 30 minutes on three other days. And it’s generally recommended you do your activity in chunks of 10 or more minutes.
That may change, though. The U.S. Department of Health and Human Services has removed the minimum of ten minutes of exercise at a time from their guidelines. As long as you get your 150 minutes or more per week, it doesn’t matter if you do it in 20, 10 or 2 minute increments. It’s the total amount of movement that counts.
These guidelines are quite different from the ones I grew up on. I was told to get 20-60 minutes of exercise, 3-5 days per week at about 60% to 80% of my maximum heart rate. If your exercise follows this pattern, great. But these guidelines were complicated having to calculate a target heart rate. Plus they gave people an all or none impression, such that if you couldn’t achieve all of this you might as well do nothing.
What about counting steps?
Then there’s the recommendation to aim for 10 000 steps of walking per day. Where does this fit in? Despite being promoted on your FitBit, pedometer or other wearable device, this isn’t an official exercise guideline. This target was created as a marketing campaign in Japan leading up to the 1964 Tokyo Olympics. It’s a nice round number, easy to remember and walking is the most common type of activity.
But 10 000 steps per day is far above the minimal guidelines. A reasonable pace for many of us is about 100 steps/minute. At this pace, 10 000 steps works out to 100 minutes of time in a day or 700 minutes per week; nearly five times the official guidelines.
So how much exercise do I need?
Before we get to that, we need to recognize guidelines are recommendations based on expert opinion. Opinions that take into account the benefits of exercise along with what may be feasible for most people. There isn’t anything magical of doing 150 minutes of activity per week. There’s really no difference between 149 minutes and 151 minutes. Likewise doing 9999 steps in a day is no different from 10 001 steps.
From a health point of view, the greatest gains of exercise come from doing nothing to something. For the person who does no activity at all (approximately 80% of people don’t meet the guidelines), any activity is beneficial. Even getting up and walking around for two minutes can help keep your blood sugar in check. If you do 150 minutes per week, that’s about a 10% reduction in chance of early death.
But it doesn’t stop there. With exercise, the more you do, the greater the benefits. In terms of reducing your chances of getting disease and early death, my research has shown the benefits continue up until about 750 minutes per week. This is five times the minimal recommended amount and associated with a 25% reduction in early death. At higher amounts of activity you’ll continue to get increased benefits of exercise, just at a slower rate.
If counting steps is your thing, just recognize that your pedometer, or other type of step counter, will record all the steps you take throughout the day. Even those steps at low levels of intensity. This means you could get 10 000 or more steps with none of them being of moderate or vigorous intensity. As a result, you wouldn’t meet the recommended guidelines. That being said, as little as 4000 steps in a day has been shown to reduce chance of early death by more than half compared to people doing no steps.
What amount is right for you?
To figure out just how much exercise is ideal for you depends on two things. One, how much activity you’re doing now (plus your current fitness level) and two, what are your goals. These things go hand-in-hand.
When setting goals, in order for them to be realistic and feasible, you need to take into account what your starting point is. If you’re currently doing leisurely walks and have never run before, setting a goal of doing a 10 km run in the next month might not be realistic.
Perhaps you want to lose weight. While I’ve written before that exercise isn’t great for weight loss, it is an important component of a weight loss program. Very few physical activity guidelines exist specifically for weight loss, but the ones that do, suggest up to an hour per day of activity.
Guidelines are Suggested Minimums
For those of you who are regularly active and doing more exercise than the guidelines, good for you and keep it up. The guidelines are minimal recommendations, and they actually suggest everyone progresses to doing more. The point being, if you are doing more than the guidelines, don’t reduce you’re activity. And if you’re just meeting the guidelines, try and do some more for even greater benefits.
If you want to improve your fitness level, you can only do that by doing more than you’re doing now. By doing more, you challenge your body physically, which over time will adapt and get in better shape. Again this depends on your starting point. If you want to run a faster 5 km, then you’ll need to go for longer runs or do harder training sessions, or do both. However, for elderly people who are inactive, even doing simple weight exercises can improve fitness.
The guidelines for exercise provide a great lower threshold for which we should all be meeting. From there, however, how much you need to be doing can be individualized taking into account your current fitness and activity goals. And remember, the best exercise program is the one that you can maintain for your entire life.
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This post was originally published on June 30, 2017 and updated on October 14, 2020.