The Relativity of Exercise

This morning I encountered an aggravating report on Quartz, Even if you start after age 40, endurance training can help your heart. It’s a very short write up of a presentation abstract that seems to be saying something important when it doesn’t say much at all.

The study the abstract is based on has yet to be published, so the reporter has not read the research itself. The article is based on an abstract and a (perhaps more than one) press release. The article is accompanied by a Reuters photo of a nearly naked elderly Asian man doing some kind of outdoor exercise in the winter (All tree branches are covered in frost or snow) and accompanied by the caption “No excuses.”

The article itself isn’t terribly startling. The researchers set out to determine if men who have been doing “endurance training” (defined as “running or cycling regimens of at least five hours per week”), but who did not start these regimens until after the age of 40 had more, less or equivalently healthy hearts as men who performed similar exercise regimens, but had started before the age of 30. OK, kind of narrow, but a reasonable thing to measure. The overall goal was to figure out if doing this kind of training, regardless of how late in life it started, would provide the individual with a healthier heart:

As reported in the abstract, the research concluded: “Regardless of the age at which it has been started, relatively intense endurance training presents the same benefits on heart and its regulation by autonomic nervous system in healthy senior men.” Resting heart rates were less than 2 beats per minute lower in the T30 group compared to the T40 group, both being close to 60 BPM. Maximal oxygen uptake was comparable. Diastolic function at rest was marginally better in the T30 group, though both T30 and T40 were significantly better than the non-exercising control group (though we’ll get back to that “control group” in a minute). During exercise, diastolic function was not measurably different between any of the groups. There was no measurable difference in systolic function between the three groups. The thickness of artery walls in the T30 and T40 groups were comparable, and less thick than in the control group. In short, regular sustained exercise can do you measurable good, even if you’re an old fart.

Here’s the basic problem with the study, and what the reporter skates over in the article – the control group is a mix of men, some of whom exercise regularly and some of whom don’t. They are not non-exercisers. Some fraction of them (unreported in the abstract, though possibly present in the full study) exercise for 2 or fewer hours per week. We don’t know how they exercise. It could be intensive or lackadaisical. We don’t know if there are statistical differences between mild exercisers and true non-exercisers.

Then there is the elephant in the middle of the room – what about healthy senior men who do exercise for the same number of hours per week (>5) as the test groups and whose exercise is not “intensive” but is, well, ordinary – walks, casual bike riding, maybe an easy game of tennis or a senior splash session at the pool? What is their rate of improvement over the control group?

The basic problem here is the article, starting with its completely disconnected image (the exercise in the study is running/jogging, not resistance training) and an exhortation that you Have No Excuse not to be out in dangerous weather (for which you are inappropriately attired), engages in a sleight-of-hand manuever that elides non-exercise with moderate exercise, erasing that middle ground as an acceptable fitness option. Intensive training = “getting in shape” and the final quote from the head researcher implies that only intensive training will result in bone density, muscle mass and reducing oxidative stress (Never mind that bone density and muscle mass are not significantly affected by the cardio training covered in the study, and are more effectively built through resistance training…). There’s some hand waving that you “can start” with a short stroll, but the message is exercise intensively or else your heart won’t be healthy.

This is not demonstrated by the research. The research does not address the heart benefits from moderate exercise for men. It may be that the delta between moderate intensity exercise – the kind most people are more likely to work into their lives than intensive exercise – and non-exercise, mild exercise and intensive exercise is in favor of moderate exercise. It may be that a far less punishing regimen than more than 5 hours of hard running and fast bicycling per week is more than sufficient to improve heart function. Something missing from the abstract (though perhaps present in the full study) is any accounting for injuries due to intensive training. How many times are these guys unable to exercise, or are performing in pain, due to physical trauma caused by the intensive training? This is a minor quibble, however, as it is clear that the research is focused on changes to the heart’s condition and performance.

What this Quartz article does is reproduce the exercise-to-excess message that dominates the media. The world has been divided up into the porcine lard-asses who loll on the couch whilst shoving Cheetos and pizza down their gullets and the amazingly fit and ripped supermen who do marathons for fun and can bench press quintuple their own weight. You have to go to fitness Boot Camp, not just have a stroll around the neighborhood. You must do Insanity workouts, not a little aerobic fun. You must lift heavy, or you might as well not go to the gym. Less than all-out (because you’re “all in”)  training regimens indicate that you just aren’t serious about your health.

Training regimens. What are you training for? Why are you regimented? It’s an approach to one’s own body that is adversarial. The body must be coerced into behaving itself and performing just so.

Physical activity, in the absence of medical conditions where it would be counter-productive, is a very good thing. I am firmly convinced that one major factor underlying the increase in average body mass over the last three decades is a decline in opportunities for safe, moderate physical exertion that is not “exercise.” My advice to anyone who is discontented with their current physical condition is to try to expand their activities, especially low-impact, easy-to-do stuff like walking. It does improve your heart health, it does make you stronger, even if it does not leave you dripping in sweat, gasping for air and shaking from exhaustion.

Exercise is one factor in an individual’s health. “Maximum” is not the same as “sufficient” and intense exercise carries its own risks. When people are being exhorted to move more, it’s not motivating to be told that the right way to do it is a manner only a small number of people are psychologically, physically and financially able to perform.


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