Thanks for the article.
Of course we need to consider the source...
It helps to read an article very carefully, and pay special attention to the primary source references. With that in mind, let's look at a few of them.
Lead author Dr James O’Keefe, of Saint Luke’s Hospital of Kansas City, said exercise was generally beneficial for health but could tip into becoming harmful when taken to excessive lengths.
So excessive exercise is harmful. And water is wet. Noted...
Dr O’Keefe and colleagues said research suggests that extreme endurance training can cause transient structural cardiovascular changes and elevations of cardiac biomarkers, all of which return to normal within one week.
But for some individuals, over months and years of repetitive injury, this process can lead to the development of patchy scarring of certain areas of the heart, and abnormal heart rhythms.
So most people are find even when engaging in "extreme" endurance training
. And some individuals, not so much. Noted...
So what's the magnitude of this minority which can be vulnerable to "extreme" endurance training?
approximately 12 per cent
Here's probably the best quote.
He said ‘Physical exercise, though not a drug, possesses many traits of a powerful pharmacologic agent.
A routine of daily physical activity can be highly effective for prevention and treatment of many diseases, including coronary heart disease, hypertension, heart failure, and obesity.
However, as with any pharmacologic agent, a safe upper dose limit potentially exists, beyond which the adverse effects of physical exercise, such as musculoskeletal trauma and cardiovascular stress, may outweigh its benefits.’
OK. There is a safe upper dose limit. (Zzzz....) Noted.
I do take exception to this remark however. Intense exercise releases endorphins, and endorphins are indeed an endogenous "drug." Morphine was synthesized to mimic its effect on our body. Runner's high anyone? Ever heard anyone say they were "horny for some contact"?
There's a lot of obvious stuff here. We're just now understanding the detail.
Once upon a time I thought I'd put running a marathon on my bucket list. But then I lost my lateral meniscus (decades ago) in my knee which is Nature's shock absorber. So am I going to train to run 26 miles on concrete w/o a shock absorber in my knee? I think not.
Personally I'm into anaerobic training (weight training, interval training, etc.). Researchers are just now catching up to what many of us in the gym know. But whatever... And yes, there's such a thing as a sweet spot for that kind of training as well. Too much is too much. (My Forrest Gump remark of the day.)
People don't play football to make their knees more healthy, and they don't run marathons to maximize their health. They do it because it's fun and it's better than smoking and letting yourself get fat. Yes, exercise can be vice. But there are worse.