I watched a documentary recently that went into detail about how your internal body clock functions and what it affects. I was surprised to learn that it’s so much more than your internal clock telling you when to wake up and when to get sleepy. It’s tied to numerous functions in your body, which in turn affects your performance on various tasks during different times of day.

Rather than try to repeat everything the program said, I will recap the highlights and take-aways that I think are important for our daily lives. The following points assume you have an average sleep schedule where you wake somewhere between 6am and 8am. You may need to adjust the hours according to your own sleep schedule, but at least you get an idea of what I’m talking about.

• Between 6am and noon is when your body has the highest blood pressure. Blood is thicker and arteries are harder due to whatever maintenance your body was performing during sleep. So until your body “revs up” and rights your blood pressure, this is the worst time to exercise or get involved in a high-stress activity. I think it was something like 20-30% of all strokes and/or heart attacks (can’t recall which, or if it was both) happen in the morning.
• You are most alert and do your best thinking between 10am and 2pm. So if you have a tough problem to solve or need to be at your mental best, try to do it during this time.
• Your body experiences a natural dip in productivity between 2pm and 4pm. Regardless of what you ate for lunch, the body’s cycle slows down during this time. You can’t be at peak performance all the time. A 15-minute nap can work wonders during this period.
• The best time for exercise and physical activity is between 4pm and 8pm. I forget exactly why this was the case, but I guess after the 2 hours of downtime, your body revs up again and is ready for action. Top athletes have learned to schedule their attempts to beat records during this time period.
• After 9pm, your ability to digest decreases dramatically. As your body gets ready to wind down, insulin becomes less effective, which causes sugar levels in your blood to increase if you’ve been eating late.
• The sun plays a major role in your body clock’s synchronization. If you need to adjust your internal clock so you can rise earlier, spend some time in the morning sun. Then in the afternoon wear sunglasses or stay indoors.
• If you need to adjust your internal clock so you sleep later, spend some time in the afternoon sun. Stay indoors or wear sunglasses in the morning. These last two bullet points are a great way to combat jet lag.
• Those who work night and graveyard shifts statically have higher incidents of maladies like cancer, heart disease, etc. They are not resting when their body clock has scheduled maintenance, so the health of these night owls suffers as a result.

By keeping these points in mind, we can enhance our health and performance by scheduling our activities during certain times. It’s good to be spontaneous, but your body has an agenda of its own.

*The ideas and statements in this post were taken from a documentary on The Science Channel. I’m sorry to say I can’t recall its title.