Those people who sit at their desks scorning the smokers outside the window might have to swallow their snickers if they haven’t been working out. A new Cleveland Clinic study just published in the Journal of the American Medical Association found that shunning exercise is more lethal than taking up smoking or having diabetes or even heart disease.
The study involved 122,000 individuals who were followed between 1991 and 2014. Periodically, the subjects took aerobic fitness tests. The researchers found that those with the lowest cardiovascular fitness levels—in other words, the non-exercisers—had off-the-charts mortality rates compared to the most fit. In fact, those who exercised the most had a startling 500-percent lower risk of death than sedentary individuals. Those who exercised a moderate amount had nearly 400 percent lower death risk than those who exercised a little. The non-exercisers had double the mortality risk of those suffering from kidney failure who were on dialysis and triple the risk of smokers.
The study’s lead author, Dr. Wael Jaber, said, “Being unfit on a treadmill or in an exercise stress test has a worse prognosis, as far as death, than being hypertensive, being diabetic or being a current smoker. We’ve never seen something as pronounced as this and as objective as this.”
The benefit of fitness was most pronounced for elite athletes and ultra-exercisers, a surprise to the scientists, since experts had long assumed too much exercise took a toll and ultimately diminished health. Also, it turned out that females benefited even more from exercise than did men, as did those over the age of 70.
Meanwhile, two new studies from the University of Liverpool and McMaster University found that taking a break from exercise does far more profound harm to older individuals than to younger people. The studies tracked active individuals who cut their exercise levels and started sitting more. Within two weeks of stopping exercise, the participants experienced a rapid increase in their blood sugar levels, a decline in insulin sensitivity, and significant weight gain. After the two weeks, participants returned to their previous exercise regimen. Those subjects who were college-aged regained their previous fitness level within a few days, with their blood sugar levels and so on returning to healthy levels, but those over the age of 65 continued to show the metabolic changes caused by inactivity. Even two weeks after they returned to their exercise regimens, the metabolic changes that had occurred when they became lethargic remained exactly in the same place, without showing any signs of improvement. The researchers concluded that older individuals who stop exercising may take months to regain prior fitness levels even after they start exercising again.
Another study a few years prior found related results. That study, an offshoot of the European Prospective Investigation into Cancer and Nutrition (EPIC), tracked weight and activity levels of 334,161 individuals over a 12-year period. The study concluded that obesity, while certainly not great for health, is only half as deadly as not exercising. Prior to that study, in 2012, the medical journal Lancet reported that one out of every 10 deaths on the planet could be traced to lack of exercise (current research would likely up the percentage). Time Magazine called death by inactivity a “global pandemic.”
But even if you quit exercising and manage to beat the mortality odds, studies show that the quality of your life is likely to suffer. In 2013, the American Journal of Preventative Medicine reviewed 30 studies on depression and observed that 25 of them found that lack of exercise was a significant risk factor. And as we’ve written before, not exercising links to many diseases that make life unpleasant, at best, including cancer, Alzheimer’s, and osteoporosis, which can lead to falls and result in disability.
It’s rather stunning that although lack of exercise is nearly as deadly as walking into a snake pit—something nobody in their right mind would do—36 percent of adults in the US engage in absolutely no exercise in their leisure time, not even walking. And as we’ve written before, 80 percent of Americans don’t get the CDC’s minimum recommended amount of exercise.
Of course, most of us have periods of time when we can’t exercise in spite of good intentions—perhaps because of illness or injury, or because of travel, or because of crises at work or home. But for many inactive people, the excuse is more like “it’s cold outside” or “I’m too overweight to wear workout clothes” or “I’m so out of shape that I couldn’t handle anything strenuous.”
If the prospect of going outside for a run or dragging yourself to a fitness class seems too overwhelming, consider that to reduce mortality risk, you don’t need to spend hours in the gym (although that might provide the greatest benefit.) In the EPIC study cited above, the researchers compared inactive subjects (defined as being inactive at work plus not doing any exercise) to moderately inactive subjects and found that adding just the smallest amount of exercise made a big difference. Brisk walking for 20 minutes a day reduced the risk of death among those in sedentary occupations by as much as 30 percent. The advantage was greatest for those in the normal weight range, although even obese people benefited. The advantage remains even if that brisk walk is to pick up donuts at Krispy Kreme. And if you add a bit of intentional exercise to achieve the 150 recommended minutes a week, your death risk plummets.
The scientists noted that perhaps doctors should be writing prescriptions for exercise before prescribing drugs. Sounds like a plan.