What Is The Best Time of Day to Work Out? (Does It Matter?)

[01dragonslayer]

For one reason or another, we all have a specific time of the day that we set aside for training.
For you, that time could be early in the morning before the day begins.
For someone else, it could be in the late afternoon, or in the evening, after work.
And as with most other aspects of fitness, a logical question arises:
“What is the best time of day to work out?”
As it turns out, there is some science to the answer and the time of day you choose to train could influence your results.

But, One Factor Matters More Than Any Other: Adherence​

Unquestionably, the best time to train is one that you can adhere to and consistently show up at the gym. Not all of us have the luxury to pick between different times of the day to train. We’ve got school, work, family, and more.

Now, for some people, “not having time” means “I’ve got better things to do” and they don’t value training as much. It’s just not a priority for them.
But, for other people, getting to the gym is a challenge in and of itself and if your schedule is particularly hectic, but you’re still finding time to get to the gym on a regular basis, you shouldn’t beat yourself up.
As long as you consistently show up, do the work, eat enough calories (and protein), and rest, you will build muscle and get stronger.

Why Is There a “Best Time” to Train?​

Generally speaking, within a 24-hour frame, all of us experience highs and lows in energy levels, cognitive function, athletic performance, willingness, and motivation.
Most people with a regular sleeping pattern (i.e., going to bed at 10-12 PM and waking up at 6-8 AM) are weaker and more sluggish in the earlier part of the day and feel stronger and more energetic in the afternoon and evening.
Of course, if your schedule demands better performance in the first half of the day, your body adapts. For example, if you work a physically demanding job and do the bulk of your work from morning to afternoon, or you train in the morning.
Now, our ability to perform fluctuates in accordance with our circadian rhythm.
The circadian rhythm is like an internal 24-hour biological clock that regulates our sleep-wake cycle, hormone secretion, central nervous system activity, energy metabolism, and core body temperature.

Let’s take a look at two important factors for performance individually, over a 24-hour period:

1.Hormone secretion​

In this section, we’ll take a look at two hormones: testosterone and cortisol.
I’ve covered the importance of testosterone before. A crucial hormone for muscle growth and strength development. Cortisol, on the other hand, has catabolic effects and having chronically elevated levels of it can be a big problem.
Now, the ratio between testosterone and cortisol or T/C has been used to predict athletic performance, monitor anabolism/catabolism, and as a measure of overtraining (1, 2). It’s been accepted as ideal to train when your T/C ratio is high.
Over a 24-hour period, testosterone levels fluctuate. It’s high during the night, and lower during the day.

Cortisol is low at night, rapidly increases in the morning (or upon awakening), and progressively decreases during the day.

Now, as you can see from the illustrations, T/C ratio is highest in the afternoon and evening. Exercise during that time has been shown to cause the smallest increase in cortisol. Some research also suggests that cortisol levels normalize quicker when the subjects train in the later part of the day.

2.Core body temperature​

Much like hormone secretion, core body temperature also follows a 24-hour pattern. Core body temperature is the measurement of the heat at which your body is operating at different points of the day.
For better athletic performance, the temperature requirement is higher than it is for other, less stressful processes. Here’s a direct quote from a review article:
The majority of components of sports performance, e.g. flexibility, muscle strength, short term high power output, vary with time of day in a sinusoidal manner and peak in the early evening close to the daily maximum in body temperature.
A quick note: The word sinusoidal is synonymous with terms such as: relating to, shaped like, or varying according to a sine wave, which itself is a smooth, periodic variation of something. In our case, core body temperature over a 24-hour period. Yes, I had to google that.
Simply put, athletic performance gradually improves as your core body temperature reaches its peak in the later part of the day. It looks something like this:

There we are, cut-and-dried, training in the later part of the day is superior to training in the morning. Or is it?

Training in the Morning: It’s Better for Some People​

With all of that out of the way, you might be thinking:
“Well, what if I can only train in the morning? Am I screwed then?”
Or...
“I’ve been training in the morning for years, and I’ve made great gains!”
Like with most other aspects of training, the best time of day to have your workouts and get the best possible results will be somewhat individual. Yes, hormonal secretion and core body temperature do play a role in how well you perform at the gym, but other factors require consideration.
For example, if you work a very stressful job and barely muster up enough energy and motivation to get to the gym after work, you may benefit much more from having morning workouts.
Or maybe, like myself, you are a morning person and find yourself to be much more energetic and productive in the earlier part of the day. This is regarded as strong morningness and is directly linked to your chronotype. In that case, why would you sacrifice that energy peak and instead have your workouts at 6 PM?
Or maybe, it comes down to pure logistics. Even if you are not tired or demotivated to train in the evening, you might regularly have obligations to your family or errands for your business that either force you to have quick, half-assed workouts or miss them all together. Would you then consider that having regular, uninterrupted workouts in the morning is better?

But Phil, how to optimize my morning workouts?​

If for one reason or another you decide that training in the morning is better for you, there are some tips you can use to both smooth out the transition and have very productive workouts:
1.Hydrate as soon as you wake up.
Dehydration has been linked to decreased athletic performance and cognitive function, and upon waking up in the morning, you will be somewhat dehydrated. It’s a good idea to drink 0.5 to 1 liter (17-34 oz.) of water as you wake up.
You should also get a bottle of water to drink during your workout.
2.Have a small meal or train fasted/take some leucine.
Food digestion takes time, especially when the meal is larger and contains protein, slow-digesting carbs, and fats. Unless you eat 2 hours before your morning training, having a big breakfast beforehand could make you feel sick during the workout.
Instead, either have a small meal of 15-30 grams of protein and 30-60 grams of carbs, or train fasted. If you do train fasted, consider taking 2-5 grams of leucine before your workout as it has been shown to stimulate muscle protein synthesis. (Or, at least, in your case, slow muscle protein breakdown.)
In any case, if you are eating more calories (around maintenance), you can probably afford to train fasted and have excellent workouts. On the other hand, if you are cutting, then you might want to have a small pre-workout breakfast for extra energy.
3.Use coffee as a pre-workout.
As a stimulant, caffeine can give you the kick in the butt you need for morning training. A dose of 3 mg per kg of body weight has been shown to increase neuromuscular readiness close to afternoon levels.
But there is one drawback:
Consuming caffeine regularly makes you develop a tolerance to it, and the potential performance boost can decrease over time.
4.Warm-up extra well.
As we discussed, your core body temperature is lower in the morning. Couple that with the fact that you’ve been inactive for several hours beforehand (well, sleeping) and you’ve got your result:
You feel stiff and immobile.
To get yourself correctly warmed up and fluid for your workouts, you need to spend extra time. An excellent way to kill two birds with one stone is to bike or jog to the gym.
If that’s not an option, do some cardio for 3-5 minutes when you get there. Walk on the treadmill, jump a rope, or cycle on a stationary bike.
You’ll raise your body temperature, get your heart rate going, and loosen up your body a bit.
After that, you can proceed to your dynamic warm-up. You should also spend extra time warming up your shoulders.
Once that is done, begin your warm-up sets on the first exercise. For example, if your first exercise is the squat and you train with 315 pounds, do it like this:

Set 1 (warm-up)	45 lbs (bar only) for 15-25 reps
Set 2 (warm-up)	135 lbs for 6-8 reps
Set 3 (warm-up)	185 lbs for 5 reps
Set 4 (warm-up)	245 lbs for 2 reps
Set 5 (warm-up)	285 lbs for 1 rep
Set 6 (first working set)	315 lbs

Back when I used to train in the morning, I would have days where I barely warmed up and believe me, the 15 minutes you’ll spend doing so are going to make a huge difference.
I’ve also heard that having a hot shower in the morning before hitting the gym helps raise body temperature and loosens you up quite a bit, but I don’t have experience with that. You can comment down below if you’ve tried it.
5.Consider lowering the weight.
When you first start training in the morning, you’ll most likely notice something:
You’ll be weaker than usual. And that’s normal. Decrease the weights as needed to get your repetitions in and don’t worry, because you’ll adapt.
Sedliak et al. reviewed the literature and concluded that short-term strength decrease is about 5-10% in the morning. The term is ‘morning neuromuscular deficit.’
But, the neuromuscular deficit can be eliminated if you persistently train in the morning. Research suggests that it takes about five weeks to get in the groove (one, two, three). For me, it took less than two weeks to start lifting my standard weights in the morning.

The Bottom Line​

At the end of the day, whether you train in the morning or evening is not as important as how consistent you are with the time of day, and how you apply yourself.
If your schedule doesn’t give you much time to train in the later part of the day, or you have a particularly draining job, then having your workouts at that time might not be the best idea. On the other hand, if nothing is stopping you from having productive workouts then, stick with that.
If, like me, you are a morning person and find yourself to be stronger, most energetic and productive in the morning, by all means, train then. There’s no point in fighting against your biology.
We are all different, and there is no one answer for everyone. Some people will do better training in the morning, and some are better off training later. Many different factors influence that, but it’s important to keep in mind that your body will adapt to whatever you throw at it.
Stick to training at the same time each day and don’t fret about minor details.