Communicating the Right Message - How Much Should You Exercise, Really?

"Coming up, the reason less exercise could be good for you."

That was the teaser from the news anchor as we were getting ready, accompanied by the screen graphic reading "LESS EXERCISE".  Before that, he was explaining that not going to the gym because of the bad weather today could be a good thing.

Fitness is a hobby of mine, so I started trying to guess what it would be.

The need to rest?
The dangers of over-working a given muscle group?
Overemphasizing cardio over resistance training?  Vice versa?
Perhaps the research out of Copenhagen in 2012 that showed that 30 minutes of exercise a day was as effective as 60 minutes?[1,2]

Nope.

When they finally got around to the story, it is preceded by a 36-second story on a new weight-loss medical device that is being fast-tracked through the FDA and that it might be covered by insurance soon.  The story felt a little too much like an advertisement.

Oh, how I long for the halcyon days when using surgery to solve weight loss was considered extreme.

The new graphic pops up "REALISTIC EXERCISE GOALS".  Hmm, already a different message, but this time it is more accurate.  They spend 16 seconds on this.  However, the message they convey is that you should exercise 60 minutes a week and they cite 20-minute brisk walks as the exemplar.  It's not technically wrong, but it is certainly incomplete.

What's The Real Story?

The story they are covering relates to comments made by Dr. Philipe de Souto Barreto[3] that there is a real concern in giving inactive people unrealistic exercise goals, based on two recent papers in the British Medical Journal.  The researchers are not telling people that exercising 150 minutes a week is a bad idea.  Rather, they are saying that generic goal may not be effective for sedentary patients that do not exercise; it's too much of a leap.

Here are the "Key Messages" from his article[3], verbatim:

• "Physical activity promotes health through a dose-response relation so the greatest health gains can be achieved in the least active people"
• "Policies and actions to promote physical activity should focus on people who are fully sedentary"
• "The main goal for fully inactive people should be to make small incremental increases in physical activities in their daily life rather than reaching current recommendations"

Overall, he makes the case that there are great health benefits for a given population if we can just get the inactive people exercising at all.

Current Recommendations for Activity

What should your activity targets be?  The World Health Organization Recommends the following for adults[4]:

• "...at least 150 minutes of moderate-intensity aerobic physical activity throughout the week or do at least 75 minutes of vigorous-intensity aerobic physical activity throughout the week or an equivalent combination of moderate- and vigorous-intensity activity."
• "Aerobic activity should be performed in bouts of at least 10 minutes duration."
• "For additional health benefits...increase their moderate-intensity aerobic physical activity to 300 minutes per week, or engage in 150 minutes of vigorous-intensity aerobic physical activity per week, or an equivalent combination of moderate-and vigorous-intensity activity.
• "Older adults, with poor mobility, should perform physical activity to enhance balance and prevent falls on 3 or more days per week."
• "Muscle-strengthening activities, involving major muscle groups, should be done on 2 or more days a week."
• "When older adults cannot do the recommended amounts of physical activity due to health conditions, they should be as physically active as their abilities and conditions allow."

But if that is too much for you...

Any exercise is better than none.

Do what you can.

Slowly increase the time or intensity.

It's easier than you think and it really is a great tonic for the body. :-)

Sources

1. http://www.sciencedaily.com/releases/2012/08/120822125028.htm
2. M. Rosenkilde, P. L. Auerbach, M. H. Reichkendler, T. Ploug, B. M. Stallknecht, A. Sjodin. Body fat loss and compensatory mechanisms in response to different doses of aerobic exercise - a randomized controlled trial in overweight sedentary males. AJP: Regulatory, Integrative and Comparative Physiology, 2012; DOI: http://ajpregu.physiology.org/content/303/6/R571
3. http://www.bmj.com/content/350/bmj.h23
4. http://www.who.int/dietphysicalactivity/factsheet_recommendations/en/