Circadian Rhythm Related To Fitness

If you’re wondering what the optimal times are to engage in certain activities, listen to your body’s circadian rhythms. Circadian rhythms are physiological, mental and behavioral changes governed by the body within a 24-hour clock, according to the National Institute of General Medical Sciences. They are affected by environmental cues, such as sunlight, darkness and temperature.

Circadian rhythms influence sleep/wake cycles, hormone release, body temperature and other important bodily functions, and these rhythms change as we get older. In the mornings with exposure to light, the brain sends signals to raise body temperature and produce hormones like cortisol, reports the National Sleep Foundation. Cortisol is produced in response to stress as well as according to natural circadian rhythm cycles. It helps give us energy in the morning, and levels decrease throughout the day. The brain also responds to light by delaying the release of other hormones like melatonin, which is associated with sleep and produced when we’re exposed to darkness. Melatonin levels rise in the evening and stay elevated throughout the night, promoting sleep. All this means that, based on age, there is a best time to be doing everything in our lives, like going to sleep and waking up, exercising, and even having a cocktail.

As we get older, the melatonin in our bodies starts decreasing, so we wake up earlier and earlier. The change begins in our thirties. A study from Paul Kelley and Oxford University states that the ideal wake-up time when we’re in our twenties is 9:30 a.m.; in our thirties, 8 a.m.; in our forties, 7:30 a.m.; in our fifties, 7 a.m.; and in our sixties, 6:30 a.m. This means, of course, we need to adjust our bedtime to match our wakeup time to get the rest we need.

Recommended Sleep
The National Sleep Foundation recommends adults get the following amount of sleep:

  • Adults — 7 to 9 hours
  • Older Adults 65+ — 7 to 8 hours

Our abilities to focus and perform are also affected by circadian rhythms. The best time to start work is 2.5 to 3 hours after you wake up. That’s when we’re past the sleep inertia or grogginess stage, and when we’re at our most alert. For someone in their twenties, that’s around noon. Unfortunately, American society is radically out of whack with work and school start times, and most of us aren’t self-employed and can’t begin work at 11 a.m. or 12 p.m. We are a culture of do more and sleep less.

The optimal time to work out is around four hours before bedtime – that’s when we’re at our peak strength and lung function. In your thirties, that’s around 7 p.m.; in your forties, 6 p.m.; and in your fifties, around 5 p.m.

Since people in their twenties often enjoy a bedtime as late as 1 a.m., a meal at around 9:30 serves as an energy boost. An 8 p.m. meal is ideal for people in their thirties and forties. People in their fifties should eat dinner around 7 p.m. and in their sixties, around 6:30, to leave optimal time to digest (and avoid heartburn).

We recommend sleeping in a dark cool environment to maximize your circadian sleep cycle. Not having any bright screens in your sleeping space. I like to personally leave my cell phone outside of my room. Avoid watching tv or doing anything involving bright lights before bed time. I personally use a circadian sleep clock to wake up me up as it really sets my start to a productive day! Below is a link for a recommended clock!