What is the best time of day to work out? A lot of people are worried about whether they’re lifting at the “wrong time” of day and it’s not surprising because there’s a lot of conflicting advice on this subject. On one hand, the conventional wisdom says you should train in the morning so you start your day on the right foot physically as well as mentally. Some trainers make a good point about that when they say if you train in the morning, you’re not only less likely to blow off your workout later in the day, you’re more likely to stick with your diet the rest of the day so you stay consistent with the good start you had.
On the other hand, studies show that maximum strength and power is lower in the morning and that muscle strength, muscle power and sprint performance peak between 4:00 p.m. and 8:00 p.m. There have also been some interesting analyses done in sports, with more world records broken in the late afternoon and early evening. These are some of the reasons why you might hear coaches say it’s better to do maximum strength, power and other intense training later in the day.
But the real answer isn’t that black and white, though it is simple. If you look at all the research in the context of who was studied, how long they were studied for, and what their goals were, or you just look at your own experience to see what works for you, you’ll probably reach the same conclusion: the time of day you lift is not the most important factor in your success – it’s one of the small details – and you shouldn’t stress over it.
Why do some studies show a difference in performance with different training times?
One explanation is circadian rhythms. We know that a variety of psychological and physiological functions can change based on the time of the day. Exercise scientists are obviously interested in this because athletic performance in professional and Olympic sports is a big deal, so this has been studied a long time.
Some of the researchers noticed that the increase in strength and power in the late afternoon paralleled circadian changes in body temperature (which also peaked in the late afternoon). The theory is that the increase in core temperature has a passive warm up effect which loosens up connective tissue, reduces muscle viscosity, enhances metabolic reactions, and increases the speed of muscle contractions.
Studies have also found that tendons are stiffer in the morning. Even the muscle architecture itself (the arrangement of muscle fibers) is different as the day goes on. Dr. Stuart McGill, a professor of spine biomechanics, has suggested that some exercises (involving bending and twisting) should be avoided within an hour of rising from bed. He says the discs are filled with fluid at that time, which magnifies the stresses placed on the spine.
Basically, most people are cold, tight and their nervous system is half asleep first thing in the morning, but later in the day they’re warmer, looser and more neurologically awake because they’ve been up and moving for a while.
That means higher performance in the afternoon or early evening and lower performance in the early morning. There are at least a dozen studies showing that maximum strength and power is about 5% to 10% lower in the morning compared to the rest of the day and the difference could be as much as 21% depending on the population, the muscle groups involved and the type of training program. This is called the morning neuromuscular deficit.
Other researchers have speculated that the difference in performance is due to hormones
This hypothesis has less support, but hormone levels do fluctuate through the day. Testosterone is important for muscle growth and there’s some evidence that it rises more after a late afternoon training session than it does in the morning. The stress hormone cortisol peaks in the morning and decreases later in the day. Natural cycles of growth hormone release are influenced by the time of day as well.
Some experts recommend pm workouts for this reason alone – circadian differences in hormones or how training at different times might affect hormone release differently. But the research has always been mixed about how much short-term hormone fluctuations affect performance, and more important, whether they affect long-term results in muscle growth and strength increase at all.
Even if circadian rhythms and hormones are both involved, the time of day you train probably doesn’t matter as much as a lot of people think, especially when your goal is building muscle or general fitness or health. So now let’s take closer look at why.
First of all, you have to consider the type of training – are we talking about endurance, maximum strength, power or muscle growth?
The research on how circadian rhythms affect aerobic exercise is inconclusive. With moderate and longer duration (endurance) workouts, what time of day you do it doesn’t seem to make much difference.
The research on maximum strength and power is extensive, but what about gaining muscle – that’s not the same goal. In the past, this topic had been studied the least (I guess they were more interested in Olympic and pro sports than body building), but fortunately, that’s changing.
One of the first studies to look specifically at muscle growth (rather than power or maximum strength) was done at the University of Jyvaskla in Finland. 24 men with an average age of 23 were recruited as subjects and split up into a morning group (7:00 a.m. – 9:00 a.m. training ), and an afternoon group (5:00 p.m. – 7:00 p.m training) plus a control group.
The study was 10 weeks long, so they weren’t just looking at how time of day affected performance or hormone levels at a single workout – they were doing a weight lifting program and then measuring muscle size after almost three months of training. At the end of the study, there was no significant difference in muscle growth.
In 2017, another study was done at Comenius University in Slovakia that was again aimed at seeing how training time of day affected muscle growth. The subjects were 32 males, between the ages of 20 and 30, and they were also split into morning and afternoon groups. After 11 weeks, both groups gained muscle, but there was no significant difference in muscle gains between groups. There was also no difference in testosterone and cortisol response.
Regularity in your training schedule is important
Even when the goal is maximum strength and power, one thing we’ve learned is that your body can adjust to morning training. After 5 weeks of switching from afternoons to mornings, performance in morning workouts can increase to the same level it was when training later in the day.
In a review from the Journal of Strength and Conditioning Research, where the authors looked at all the studies put together, one of the main findings was that if you’re an athlete and you do your training at the same time of day you usually compete (your game time or meet time), you’re more likely to perform the best.
In other words, if you compete in the a.m., it’s ideal to train in the a.m.. If you compete in the p.m., train in the p.m., if you want optimal results. If you’re not training for competitive sports, that’s another reason not to worry about timing.
One way to optimize your performance might be to avoid haphazard or random training times. Also, keep in mind that if you change to morning training after being used to afternoon or evening training, you might see a decrease in performance at first until you get used to it. If you pick one time – any time – and you stick with it, eventually, your performance will equalize, so in the long run it, the timing may be less important than regularity.
Inconsistent training times could also explain why some studies said lifting later in the day is better – many of the subjects may have been used to training at that time.
Also, from a psychology point of view, when you consistently repeat a behavior, that’s how you ingrain habits. When you’re just starting out, if you don’t commit to one training schedule, you’re going to have a tough time making your training something you do automatically without needing willpower.
Gender and age might be a factor too.
In a 2018 study (Krycmarova), the researchers decided to recruit untrained older females as test subjects. The reason is they noticed that previous research on strength used trained athletes as subjects and the studies on muscle growth used younger men as subjects.
This study was designed to see how women in their sixties responded to a 12-week training program with one group training in the morning and one group in the evening. Both groups did whole body strength training with 3 sets of 10-12 reps per exercise and 2 to 3 minutes between each set.
The time of day didn’t have any major effect on any outcome including muscle growth. But there was actually a non-significant, yet measurable effect that favored increased muscle mass in the group that trained in the morning.
Does this mean that older women should lift in the morning to gain muscle, or that research is always contradicting itself? No. Actually this is more evidence that there’s no single best time to train and that you should decide for yourself when to train and that it’s based on a lot of different factors.
Put together, what does all the research conclude?
In January of 2019, a group of researchers lead by Jozo Grgic published a meta-analysis of eleven studies to see what all the best science data put together said about morning versus evening training and the effect on strength and muscle growth. The authors concluded:
“The results indicate that if you consistently train at a given time of day, the body adapts so that muscle development is similar regardless of whether you do morning or evening workouts. Take home: There is no ‘best’ time of day to work out; train when it best fits your lifestyle.”
In a 2022 a systematic review (Janssen et al) the researchers looked at the effect of training time of day on health outcomes. After analyzing 35 studies with 17,259 participants, the authors concluded, “There is no consistent evidence that physical activity at one time of day provides more favourable health benefits than physical activity at a different time of day.”
Other factors: Psychology, convenience, personal preference and sleep
There may be advantages to different training times based your age, your goals and the type of training you’re doing, but in the end, it comes down to personal preference, convenience and psychological factors as much as it does to anything biological.
Many people find that training in the morning helps them stay consistent. One positive behavior or achievement in the morning can set a positive tone for an entire day.
Some people also find that night time workouts are easier to blow off, because they’re tired, willpower-depleted, stressed or work or family issues come up and take priority (or, for some people I know, the temptation of happy hour is more appealing).
Some people say that if they train too late at night (like 10 or 11 p.m.) it disrupts their sleep.
Some people train when they train because it’s the only time they can fit it in, or it’s just when they prefer to train and that’s fine.
What’s the bottom line?
You don’t have to follow any rigid rules made by training experts or based on a single study that may not have looked at the whole picture. Instead, you should customize your training time just like every other part of your plan.
When choosing a training time, some competitive athletes might want to consider what the research says because circadian rhythms can influence training results in some cases. But ultimately the best time for you to work out is the same that a lot of common-sense trainers have been saying all along:
1. Train at the time when you feel the strongest and perform the best.
2. Train at the time you feel the most energy physically.
3. Train at the time when you feel the most alert and focused mentally.
4. Train at the time when you can stick with it the best, because it fits into your lifestyle.
5. Once you’ve chosen a training time, if possible, stick to it consistently so it becomes a habit, plus consistent training times may improve response to training.
Train hard and expect success!
Author, Burn the Fat Guide to Flexible Meal Planning For Fat Loss
Founder, Burn the Fat Inner Circle
PS. What about me? Over the years, I’ve trained at almost every hour of the night and day. The worst lifting time for me was 6 am. I had to get up at around 5:20 am to be ready for that… but I was never ready. I was a grouchy, miserable SOB and the only reason I made it is my training partner (who one time, broke into my apartment and literally dragged me out of bed). We were both prepping for a contest; we both competed. I won the middleweight and overall, but I hated every minute of lifting at those ungodly hours. Cardio before breakfast – especially right at home – at 6 or 6:30 in the morning, I could always manage.
For a while, I did a stint of lifting at 7:30 am (lifting) with my trainer Richie (“the master of pain” – who enjoyed getting up at 4 am to come torture his clients before the sun had risen) . That was better (time to drink more coffee). But not much. I took that 7:30 – 8:30 am time slot begrudgingly. Second least favorite time for me has been in the evening – after dark, with starting times after 8 pm. I feel like I’m physically dragging at that time and my mind is more scattered, especially after a high-stress workday. Afternoon training times – starting between 1pm and 4 pm have worked very well for me, and as a plus, the gym is empty, (so I can curl in the squat rack like a good meathead, and there’s no one there to yell at me). I have only been able to do that in recent years because my previous career in the gym business had me working afternoons and evenings.
The best time for me ever was in the late morning – starting time around 10 or 10:30 am. That was the time for me that I felt strongest, most energetic and most mentally ready and focused. I had time to already have a couple meals in me, plus there was enough time to drink copious amounts of Starbucks :). Being self-employed does help, because you can train any time you want… experiment… and find what works best. I also agree with the latest research: I’ve been guilty of training at miscellaneous, haphazard times, and I think that sometimes hurt my mental readiness and physical performance.
PPS. How about you? If you have experimented with multiple training times, what did you find was the best time for you? How did it affect your: 1. Workout performance, 2. Eagerness/willingness to train, 3. Consistency over time and 4. Your results over time? You can post your comments below – would love to hear from you.
About Tom Venuto, The No-BS Fat Loss Coach
Tom Venuto has been a trusted natural bodybuilding and fat loss expert since 1989. He is also a recipe creator specializing in fat-burning, muscle-building cooking. Tom is a former competitive bodybuilder and today works as a full-time fitness coach, writer, blogger, and author. In his spare time, he is an avid outdoor enthusiast and backpacker. His book, Burn The Fat, Feed The Muscle is an international bestseller, first as an ebook and now as a hardcover and audiobook. The Body Fat Solution, Tom’s book about emotional eating and long-term weight maintenance, was an Oprah Magazine and Men’s Fitness Magazine pick. Tom is also the founder of Burn The Fat Inner Circle – a fitness support community with over 52,000 members worldwide since 2006. Click here for membership details
Drust B, et al, Circadian rhythms in sports performance – an update, Chronobiology International, 22910, 21-44, 2005.
Grgic J, Shoenfeld B, et al,The effects of time of day-specific resistance training on adaptations in skeletal muscle hypertrophy and muscle strength: A systematic review and meta-analysis. Chronobiol Int. 2019 31:1-12.
Janssen I et al, Timing of physical activity within the 24-hour day and its influence on health: a systematic review, Health Promot Chronic Dis Prev Can, 42(4):129-138, 2022
Krycmarova et al, The effects of 12-week progressive strength training on strength, functional capacity, metabolic biomarkers, and serum hormone concentrations in healthy older women: morning versus evening training. Chronobiology International – The Journal of Biological and Medical Rhythm Research, 9:1-13. July 2018
Sedliak M, et al, Morphological, molecular and hormonal adaptations to early morning versus afternoon resistance training. Chronobiology International – The Journal of Biological and Medical Rhythm Research, 35(4), 2017.
Sedliak M, et al, Effect of time-of-day specific strength training on muscular hypertophy in men, Journal of Strength and Conditioning Research, 23(9), 2451-2457, 2009.
Chtourou H, The effect of training at a specific time of day: a review. Journal of Strength and Conditioning Research, 26(7):1984-2005, 2012