Why You Shouldn’t Burn More Than 4,000 Calories a Week through Exercise

Mark Sisson explains why excessive exercise can be hazardous to your health.

Everyone agrees that being sedentary is bad and unhealthy and that being active is good and healthy. The research agrees, too; regular physical activity leads to good health, longer lives, and an improved ability to function throughout normal life. When you’re able to walk to the store, carry your groceries home, take the stairs, get out of bed without struggling, pack enough lean mass to survive a stay in the hospital, and ride your bike when you want to, you’re a functional human being, and remaining active on a regular basis helps maintain this state so crucial to basic health and happiness.

But what’s often hidden amidst the blanket pro-exercise sentiment is that too much exercise can have the opposite effect on health – people can really take physical activity too far. I talk about this all the time, so much that you’ve probably got “Chronic Cardio” emblazoned across your brain and shake your head when you see some hapless soul in spandex and the latest runners heaving himself down the street, heel first. I know just how bad that stuff can be, because I did it for a large part of my life. You’ve all heard that story before, though, about how even though training cardio hard gets you “fitter” in one sense of the word, it’s actually counterproductive for a healthy long life (doubly so if you want to have some lean muscle mass and pain-free joints in your later years). Read more