Well, I hope you’ve been enjoying and learning something from the last several blogs on circadian rhythms.

So, the last section I thought I would take up is Activity or Exercise and the importance of being physically active throughout the day, and if possible, physically active outdoors in natural sunlight.

The American Heart Association has said that healthy people need 150 minutes of moderate exercise, or 75 minutes of enthusiastic exercise a week. A person can do a blend of both, or if on a time machine, one can exercise for 30 to 45 minutes or split the time into three 10 to 15-minute sessions each day.

That’s really not a lot, and should be a word of caution to not only the “slothful”, but also to those who feel they need to be out there doing it to it a few hours each day, or more!

Interesting concept, but…, there is such a thing as too much!

Now, exercise can be any physical activity that includes body movements and calorie burning. So, moderate exercise including aerobic exercise, strength or resistance exercise and stretching, will all work.




It Doesn’t Take Much Exercise to Get Results.

My son Austin, who is a Certified Personal Trainer was telling me of a study that showed if a person did 1 set of 10 reps of ANY 10 exercises, and this could be any 10, even on a Universal Circuit machine, that in one month’s time that person will have gained on average 4% more muscle mass!

Again… that’s not a lot, and wow- who wouldn’t want 4% more muscle mass especially when one understands all of the health benefits of good, healthy muscle tissue.

If a person injures himself, where does the body get the protein to repair the injury? Yes, from dietary protein, but also… from one’s muscle tissue.

Heck, even walking will do wonders. Brisk walking, taking in natural sunlight…, wow, AMAZING!!!

And even this is NOT miles and miles of walking, just enough to get the heart beating and the joints moving.

Like all things circadian, even the most advantageous times to exercise are based on timing.


The Best Times to Exercise.

The very best time is between 3 p.m. and before dinner.

This is the time a person’s muscles and agility are at their peak and working best according to the circadian clock.

Another good time is in the morning before a person breaks their fast from the night before. Lots of great sunlight, and a person’s body will still be in fat-burning mode from having not eaten since dinner the night before.

Probably one of the least desirable times to exercise would be in the evening after dinner and/or before bed. The circadian clock timing is not optimal at this time, and one tends to overheat with exercise.

Elevating one’s core temperature before bed tends to make it more difficult to go to sleep, but if this is the only time to exercise then I guess that’s it.

As Austin says, “Here’s a Pro-Tip”.

Try not to eat before exercising as this will force the body to utilize its fat stores for energy rather than burning the food you just ate.

Alright, there’s not a whole lot more I can say about activity and exercise. Our bodies were designed to move, and this has been discussed quite a bit in earlier blogs.

I will leave you with one final thought.

According to the circadian rhythms, the best time to learn and work is between 10 a.m. and 3 p.m. each day. It’s the time the brain and body are banging on all 8 cylinders.

After 3 p.m. one’s attention tends to decline and mood starts to mellow out. So it is better to get work done in the morning, and this might explain why afternoon work meetings are such a drag.


One Final Thought About Circadian Rhythms.

In my opinion that whole circadian rhythm evolved to optimize one’s living and life potential, you know, get the most out of your body and life.

To do this one MUST get appropriate, restorative sleep.

As the body sleeps, it repairs itself, regenerates and rejuvenates to handle the day and all of the future new days a person has.

This is not a diet, per se, but a lifestyle that gives a person the absolute best chance for the sleep the body needs to flourish.

So a person eats in a restricted window of time, eats healthy foods, gets plenty of movement and exercise and natural sunlight during the day so he or she can get the sleep they desperately need to not only live the life they want to live but to actually continue living!

I will invite you to once again either read Matthew Walker’s Why We Sleep or watch his YouTube and TEDtalk videos.

You simply will not believe all that sleep does for a person or at least is supposed to do for a person if that person would simply sleep!

Sleep is the magic elixir that has the greatest potential to “cure” a person, or prevent a person from the myriad of diseases and disorders that can and will ruin their life….


Yes, absolutely sleep!

As your mom and dad used to say,   “I hope I’ve made my point!”

Oh yeah,

“Now go to bed, or next time I’m coming back upstairs with the belt!” LOL!

Okay, that will do it for now.

I am sure I will have much more to discuss in regards to circadian rhythms and the importance of sleep in future blogs.

In the meantime, I really would love to know what you think about all of this so please let me know by reaching out or commenting below.

It just seems like such a simplicity to not fight nature and our bodies with every darn thing we do.

I have not found fighting nature to be a real pro-survival idea or lifestyle.

Our bodies have evolved a basic design and it is aligned with the natural world.

Take Care,

Dr. Dave

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Please give him at least a day to respond and check back on this blog post to see his response.