Talk to a few people about when is the best time to exercise and they’ll swear mornings are the best. They’ll tell you that going to the gym for a cardio session first thing in the morning makes you feel more energized throughout the day.
Then you have the people on the other side who are convinced that working out at night is better for you. They claim that the quality of your workouts is much better if you schedule them closer to your bedtime. And yes, you can sleep!
The reality is that early risers have gotten used to being active from the moment they wake up, and night owls prefer to schedule their interval training after leaving the office. It really depends on what you like , so in a way both morning and afternoon camping are equally “right” because they have found a routine that works for them.
But putting personal preference aside for now by approaching it from a more scientific angle and asking, “Okay, when should I schedule my training so I can burn fat, gain muscle, and reach my fitness goal: right after I wake up? or closer to my bedtime?
Now this is where things get interesting.
Below, we’ll present the arguments for both the AM and PM groups, discuss their merits, and conclude if THERE IS a perfect time to hit the gym to reach your fitness goal.
The case for morning training
The case for the morning workout is based primarily on two positions, both of which are very popular with the fitness community. Are:
- To gain muscle, exercise when your testosterone levels are at their highest.
- To lose fat, exercise on an empty stomach so your body uses fat stores for energy.
What makes these positions so believable is that they are both easily understood and sound scientific enough. However, if you dig deeper, you will find that these two positions are not completely off base, but they do run into some problems.
It is true that testosterone levels are at their highest in the morning and then slowly decline throughout the day. Testosterone is an anabolic (muscle growth) hormone that is secreted during sleep, just like growth hormone. Getting enough sleep has very significant effects on body composition and is crucial for both successful muscle building and fat loss, not to mention super important for having enough energy for morning workouts in the first place!
The problem is that while high testosterone levels in the morning may seem ideal for hitting the pounds, there’s another hormone that also peaks in the morning: cortisol.
In the most general terms, you can think of cortisol as the “anti-testosterone.” While testosterone is an anabolic hormone, cortisol is a “catabolic” (muscle-wearing) hormone, something that does not stimulate muscle growth. With testosterone and cortisol elevated in the morning, any supposed drive to lift weights in the morning due to testosterone levels will be largely canceled out .
Now morning workouts are better for fat loss. This position is usually related to the idea of fasted exercise leading to more fat oxidation (also known as “fat burning”), as the idea is to exercise before breakfast and burn more fat because you don’t have much glycogen (“energy”) from the food to get out.
The truth is that research on this topic is somewhat mixed. In this study of Muslim, trained rugby players who were fasting during the Islamic holy month of Ramadan, researchers found that the players were able to use their body fat for energy more efficiently during exercise than before, when they were able to eat normally. for the whole day.
However, another study published in the American Physiological Society makes the opposite case , showing that while participants who fasted before exercise had some beneficial effects, in terms of fat oxidation, there was no appreciable difference between the group that fasted and the group that did not.
This is not to say that there is nothing for morning workouts. Research conducted at Appalachian State University found that morning walks (7 a.m.) on a treadmill lower blood pressure and improve sleep better than walking at night (7 p.m.). While this is certainly a positive benefit, if you’ve previously argued that morning workouts are automatically better for your workouts due to testosterone levels or desire to train while fasted, you may not actually get much benefit, if any.
The case for afternoon/evening training
The position of those who believe in exercising in the afternoon rests on a couple of points:
- Testosterone to cortisol ratio is most conducive to muscle growth at night
- body temperature occurs in the afternoon and is related to greater strength
As mentioned above, testosterone levels are highest in the early morning, but so is cortisol. If it is desirable to exercise in the presence of elevated testosterone levels, research has shown that the optimal time to exercise is in the late afternoon due to the favorable testosterone to cortisol ratio that occurs during that time.
Where does the research on the relationship between body temperature and strength lie? In addition to the testosterone study cited above, which found that strength coincided with peak body temperature in the afternoon, there is this study that focused exclusively on body temperature in elite rugby players.
Strength was measured twice during the day, once in the morning and once in the afternoon, while core body temperature was recorded at each testing period. The study found that, in the 16 rugby players, strength was significantly correlated with body temperature: both strength and body temperature peaked in the afternoon .
A large number of studies that have examined strength in relation to time of day seem to confirm that muscles are capable of producing more force production in the afternoon, including:
- A study of sprinters tested the force produced in a series of 10 consecutive sprints performed on two occasions: between 8 and 10 a.m. and between 5 and 7 p.m. When the sprinters ran in the afternoon, they always performed better in the first three sprints than in the first three morning sprints.
- A study of cyclists performing a 60-second Wingate test (a test designed to measure anaerobic strength) assessed their strength and power at one of two times: 6 am and 6 pm Strength was measured in three ways: maximal strength , the average force during 30 seconds and the average force during the 60 seconds. All power outputs recorded in the afternoon were higher than in the morning
A common concern regarding nighttime exercise is that late-night workouts will disturb your sleep, sabotaging the recovery process. While it’s definitely a valid concern, there isn’t much to support it. When researchers actually put this concern to the test, in at least three studies , they couldn’t find a clear link between vigorous nighttime exercise and disrupted sleep.
It may be that working out at night DOES make it harder for you to fall asleep, and if that’s the case, that’s something to keep in mind. However, if you were avoiding night workouts because you were afraid of losing sleep, but hadn’t tried it yourself, you can give it a try.
So what is the answer?
It seems that, according to research, the best time to exercise, objectively, is in the afternoon. Sorry, morning workout fans.
“But wait!” comes the cry from the morning crowd: “I don’t care what your fancy inquiries and investigations say. I train so much better in the morning, and nothing you say to me can change the way I really feel in the mornings.”
To which the research would say, ” Guess what, you’re right . “
That’s right: even in the face of all this scholarship, if you feel like you perform better in your morning HIIT class than in the afternoon, chances are you’re right, and the science will back you up too. Let’s explore :
A study that sought to solve the problem of the best time of day to exercise had a group of participants exercising for 10 weeks between 5 and 7 pm. Once this was done, they were randomly assigned into two groups: one that worked in the morning between 7 and 9 in the morning and another that continued between 5 and 7 in the afternoon. Changes in muscle growth were measured for each.
The results? Yes, the afternoon group experienced a higher percentage of muscle growth compared to the morning group (3.5% vs. 2.7%), but crucially, the researchers found that this 0.8% difference is not statistically significant.
That means the changes weren’t different enough to be outside the realm of pure chance. “But still,” you might say, “given all the research in favor of night workouts, even in that study, night workouts came out ahead, statistically significant or not.” Yes, that’s true, but there could be a very reasonable explanation for this.
In a review of training at a specific time of day , the researchers noticed something interesting. While they agree that peak performances generally occur in the afternoon, they noted that this pattern is not absolute. They found that people who consistently exercise in the morning are able to overcome any “limitations” that morning workouts may have, and actually outperform their own evening performances.
Similarly, for people who exercise in the afternoon, the differences between their morning and evening performance is significantly (and unsurprisingly ) in favor of the evening, leading the researchers to conclude:
Therefore, training adaptations are greater at the time of day when training is regularly performed than at other times. – Chtourou et al. (2012)
So now, think about the previous study: the one with a night group that has a 0.8% increase over the morning group. Remember how the participants spent almost three months preparing for the study by training at night and then having some change in the morning ? What would have happened if they had prepared for the first time in the morning? Would the study have had the same results? Hard to say.
“Whatever Works”
We’ve been through a lot to say this: While it’s probably best to exercise at night, what’s far more important is
- A) make exercise a habit
- B) know consistent with how long you exercise.
Although there is plenty of research to support evening training, due to your individual situation in life, fitting in a cardio workout in the morning might make more sense for your routine. If that ‘s the case, you’re totally fine. You will not put yourself at any significant disadvantage in reaching your fitness goal.
Also, know that extremely important factors not mentioned here, such as nutrition and type of training (HIIT, cardio, etc.), play a gigantic role in your physical performance, perhaps enough to make this discussion worthwhile. debatable.
That said, if your fitness goal centers on muscle gain, it may be worth trying it out for yourself if night workouts help. You may find that exercising at night actually helps you lift more, or run further/longer.