All self-healthers know that consistent exercise is crucial to optimal health. But it’s equally important to understand when exercise is bad for you.
Of course, there are obvious times you shouldn’t exercise, like when you’ve been injured. Your body needs time to heal after an injury, and aggravating it in the name of fitness can quickly take you in the opposite direction.
Injuries aside, even if you’re in peak condition, there is one time every day when exercise is bad for you. Any guesses? Well, before I give you the answer, let’s take a look at what exercise does to your body. For starters, exercise calls your sympathetic nervous system into action, but it also recruits a response from several other body systems. The goal is to keep everything in balance as your body deals with the demands exercise puts on your physical being and your respiratory and cardiovascular systems. In other words, your body gets all worked up to accommodate your workout.
Your muscles are called upon to perform whatever action is required of them. The stress on those muscles (and the bones they’re attached to) causes tiny tears in your muscle fibers, which are repaired and regenerated by the cells of your body.
Your heart starts beating faster, and your circulatory system has its shining moment as it moves oxygen and carbon dioxide to where they belong while directing increased blood flow to the muscle groups that are being exerted.
You start breathing heavier, and your respiratory system knows exactly what to do. Your lungs need to increase their capacity for gas exchange: oxygen in, carbon dioxide out. (Carbon dioxide is a product of your muscles working hard, and it needs to be removed from your body. Once the circulatory system delivers it to your lungs, they get rid of it as quickly as possible.)
This is a super simplified explanation, but you can see that your body is called upon to do quite a lot when you exercise. Various systems are on high alert to do what they need to do in order to maintain equilibrium in your body.
Okay, folks. A show of hands from those of you who think you know the answer to this week’s question: when is exercise bad for you? I spot a couple of takers. Let’s go one step further to see if we can get any more.
You’d think this is exhausting and that your body is ready for some good, deep rest after all that exercise. And you’d be right. Regular exercise plays a significant role in helping you get restorative sleep each night. But—insert drumroll here—it takes some time for your body to calm down enough to rest.
Any more hands up? Marvelous! Yes, my friends. The answer to when exercise is bad for you is right before your normal bedtime.
Matthew Walker offers some tips for getting rejuvenating sleep in his book Why We Sleep: Unlocking the Power of Sleep and Dreams. One of his guidelines has to do with exercise. Walker explains you should get at least 30 minutes of exercise as often as you can, but just don’t do it too late in the day. Ideally, you want to wait a minimum of two or three hours after your workout before you start your bedtime routine.
If you thought exercise was good for you no matter what, you were pretty close. Nevertheless, there’s an exception to most any rule out there.