Tyler Robbins Fitness

B.Sc. Biochemistry, Certified Strength and Conditioning Specialist (CSCS), Certified CrossFit Trainer (CCFT/CF-L3), USA Weightlifting Level 1

Filtering by Tag: Circadian

The best time to work out is?...

I came across this article the other day: 

The best time to work out: Use your biorhythm for 84% more muscle

I mean, what a headline, am I right? Now keep in mind that this article is written with a (mainly) strength training mentality - lifting weights and exercising with increase in musculature/strength as a primary goal. Also, that headline is just downright asinine. How could you possibly come up with that sort of claim or number? Anyways, let's continue on.

I am always quite, well, surprised, is the best word I can think of for how I'm feeling, when articles like this one make statements about "core temperature." 

Much less contentious are the effects of your core body temperature. Core body temperature is the temperature at which your central organs operate. Enzymatic reactions are extremely sensitive to minor variations in your core body temperature. For the biological systems involved in high intensity physical exercise, the optimal temperature is relatively high.

The reason why this surprises me so much is that the human body likes to remain in a relatively steady state at all times (homeostasis). There is a very specific window of temperature, pH, as well as a other factors that have to be maintained in order for the body to function, which, in my own opinion, should be considered "optimal." There are so many processes, checks and balances, and functions being carried on in your body at all times that the very fact that you are walking around is downright astonishing to me.

Anyways, enough of my inner science nerd. This article even references a great "core temperature" diagram that I would like to share. 


Notice that the body never changes its internal temperature by more than 1 degree celsius at any time. It just can't. If it does, you die.  Therefore, exercise in the morning can be just as advantageous, assuming a proper warmup period. But this is common sense anyways...right?

It is no surprise then that most sports records are broken in the early evening [9]. More importantly, a multitude of randomized, controlled, scientific experiments support exercising in the late afternoon to early evening [12, 13]. At this time, flexibility, power and muscular strength reach their daily peak. Endurance capacity seems to have a less pronounced circadian rhythm [11, 1].

True, a connection can be made between when most  sports records are broken in the evening, but we should note a few things here. If the evening was in fact the most optimal time for strength training, then shouldn't all  of the records have times of competition in the evening? Not only that, but far too many other factors could be involved in performance levels. Here's an example; what if an athlete had a bad sleep the night prior to competition. Maybe a poor morning performance could be overcome by simply having more time to prepare throughout the day with various diet changes/additives, not to mention a well-executed warmup/prep prior to competition later in the day. I argue that evening performance allows more time throughout the day for an individual to "course correct."

Peak performance and exercise adaptations correlate strongly, so a good rule is to train when you personally perform best [19, 1].

Exactly! I have actually touched on this is the past. Basically, your body adapts and changes to meet your needs and schedule. So, if you wish to perform at your best in the morning, you should train in the morning. If you wish to perform at your best in the evening, you should train in the evening.

Not everyone has the luxury of planning their training sessions during the physiologically optimal times. ‘Real life’, whatever it means, has a way of planning things for us. Our schedules have to consider our work, study, family and other day to day activities.

However, for most people these are just excuses. ‘Not having time’ to train actually means ‘I value training less than the thing I’ll do instead’. The things you make time for are the things you prioritize. In Dutch, my native language, the word for priority is pronounced as the Dutch equivalent of prioritime. This makes a lot of linguistic sense to me. Time equals priority.

I'm glad this is brought up. Let's face it, not everyone is a professional athlete who can alter their schedule based on their training needs/goals. A large percentage of the population has to schedule exercise around their regular lives (work, family, errands, etc.).

I have always said that consistent exercise is always  better than no exercise at all. I have personally had great success exercising in the mornings. I find that I get my workout done and out of the way before the day's events get in the way, however, I realize that not everyone is a "morning person."

One thing that can  be taken from studies like this, however, is that if you are training for a specific event, and this even is to take place during the evening, then you may wish to train in the evenings, although only for a very minor advantage.