Exercise Guidelines: When Is 30 Minutes a Waste of Time?

The statistics are grim: 80% of people are not meeting the new exercise guidelines issued by the U.S. federal government’s Office of Disease Prevention and Health Promotion. Here is what they recommend for adults:

• Adults: at least 150 to 300 minutes weekly of moderate-intensity aerobic activity, or 75 to 150 minutes weekly of vigorous-intensity aerobic activity, or an equivalent combination of both, plus muscle-strengthening activities on at least two days a week
• Older adults: multicomponent physical activities that mix balance activities, aerobic activities, and strength training can help prevent falls and injuries; reduce overall sitting and replace it with light (or when possible, moderate) activity

According to a Harvard Health blog, each year in the US, an estimated 10% of premature deaths and $117 billion in healthcare costs are associated with inadequate physical activity. A data analysis published in JAMA in April 2019 found that between 2007 and 2016, total daily sitting time for adolescents and adults increased by roughly an hour.

These exercise guidelines for 30 daily minutes of activity are not too hard to achieve. You already know that a brisk walk can meet that requirement. That’s not a lot to ask if you want to prevent falls and fractures, chronic disease like diabetes and heart problems, while improving your overall health, mood, and quality of life.

Is 30 Minutes Effective or a Waste of Time?

I agree with Dr. Michael Greger, author of How Not to Die: Discover the Foods Scientifically Proven to Prevent and Reverse Disease

The exercise authorities seem to have fallen into the same trap as the nutrition authorities, recommending what they think may be achievable, rather than simply informing you what the science says and letting you make up your own mind.

Why soft peddle 30 minutes, when 60 minutes does a whole lot more good? Why not tell the public the truth? There is more to the story, and certainly well-informed seniors are capable of deciding how much exercise is appropriate and effective for themselves.

The truth, according to evidence-based science:

• Walking 150 minutes a week is better than walking 60 minutes a week.
• If you walk for 60 minutes a week it only drops your mortality rate about 3 percent.
• But walking 150 minutes a week reduces mortality rate by 7 percent compared to being sedentary.

But consider these facts if you really want to live longer:

• If you walk 300 minutes a week you drop your mortality by 14 percent.
• Yet walking twice as long (40 minutes/day) as the minimum recommended guidelines (20 minutes/day) provides you with twice the benefit in terms of reduced mortality (24 percent)!

Exercise Guidelines for 30 Minutes May Not Be Enough

I’m only using walking as an example of moderate-intensity activity and there are many other ways to be active moderately — think slightly raised heart-rate and light sweating. It can include gardening, housework, hobbies and other activities besides working out and playing sports.

For many of my athletic and active senior friends, 30 minutes isn’t enough. They are accustomed to more. Therefore, they need to challenge their bodies to get health benefits. With sports and gym exercise, you can increase heart rate and sweating into the vigorous-intensity ranges, for increased benefits.

How you spend your time is up to you. How long you engage in exercise is also up to you. Just don’t fool yourself by counting 20 to 30 minutes as healthful when you know your heart rate hasn’t changed and you’re nowhere near breaking a sweat.

I believe that part of the problem is the way the authoritative guidelines molly-coddle seniors into thinking that a little bit of light exercise is all that’s needed. Sure, something is better than nothing, but if exercising isn’t strengthening our muscles and bones enough to help us avoid falls and fractures, then the “authorities” are doing us a disservice. They are misleading us.

Or as Dr. Greger says:

The authorities are just hoping to nudge people in the right direction. It’s like the dietary guidelines advising us to “eat fewer sweets.” If only they’d give it to us straight.