Sometimes more exercise really is better.
Like when you get on the floor and try to push out 10 sit-ups, and you only do 2 and call it a day. Or when you walk outside with the intention of going for a quick jog, and turn around before you hit the end of your street.
In these instances, you would do well to just push through it and give your workout a real chance (P.S. You're lazy. I like you.).
However, there are people out there who seem to think that there is no end to the amount of good a workout can bring. They’ll set up a tent in the gym for a few hours, run 10, 15, or 20 miles every morning, or try to fit in 2 or 3 workouts into one day. To those people, I have one thing to say: Stop. Stop it right now. You’re not doing yourself any favors, in fact you might be doing damage.¹
If your goal is solely to become fitter or healthier, than there truly is such a thing as too much exercise. If you’re a professional athlete or training for an 80km footrace, then you likely can’t avoid training a lot at certain times of the year. However, if you don’t fall into that category, then there is absolutely no benefit in terms of health from exercising more than a certain amount. But how much exercise is too much?
When it comes to aerobic activity (running, swimming, etc), try not to do more than 2.5 – 3 hours per week on average. People who performed more aerobic exercise than this per week were actually shown to have shorter lifespans overall and to be at increased risk of death compared to those who do light (running at 5.5 mph) anaerobic training for 2.5 hours per week.²
In a weird twist of fate, those who regularly do more than 4 hours per week of intense aerobic exercise are actually more likely to die and less healthy than both light and moderate exercisers. More and more research has been aimed at this topic as of late, and the latest research in 2015 found amongst peer reviewed publications like Heart, the European Heart Journal and the Journal of the American College of Cardiology are all in agreement; those who exercise too much are no healthier than those who don’t exercise at all.
For some of us, that statement might hurt a little bit. Many of us take considerable pride in keeping fit and healthy, and to hear that all of the effort we’re putting in might in fact be doing us no favours over those who are sedentary definitely stings. If it’s any consolation, it’s almost certainly not your fault. Until very recently, there have been no universal recommendations across the globe that mention a safe upper limit, but it does appear that ones exists. In a world where more is almost always marketed as better, where crossfitters are encouraged to exert themselves until they can barely get up off the floor with many even succumbing to Rhabdomyolysis³, it’s no surprise that a certain amount of people over indulged in exercise – no matter how well meaning they are.
If you think about this logically, it does in fact make some sense. While sitting around all day allows arteries to clog from slower blood flow and your heart to wither in size and efficiency, exercising too much, both in theory and in the real world, serves to put too much stress on the heart, causing it to prematurely age.
“Long-term excessive exercise may be associated with coronary artery calcification, diastolic dysfunction and large artery wall stiffening,” says Dr. Peter Schnohr of Copenhagen’s Frederiksberg Hospital.2
Just as an overweights person heart has to work too hard to move the body around (and is liable to give out early), so is a persons heart who exercises too hard.
What should you take away from this all this? Science tells us that the sweet spot is approximately 1.5 – 2.5 hours of light aerobic per week. You’ll be considerably healthier than those who don’t exercise at all and those who do considerably more aerobic exercise per week. 78% less likely to die than each other those groups, in fact. As an added bonus, 2.5 hours a week of aerobic exercise (combined with a smart diet) is also more than enough to meet any fitness goal you might have, whether it’s losing fat, improving your fat-to-muscle ratio, or training for a fitness competition.