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

The optimal time of day to train is not usually something that people think about. People train when it’s convenient, when they feel like it, when they can. As a result, the decision on when to train is a byproduct of other arrangements. Such a second rate approach to planning your training sessions leads to second rate results.

There is a science to optimizing your training times. By carefully orchestrating your training schedule in accordance with your circadian rhythm, you will be stronger, faster and more powerful. After the training, you will recover better and gain more muscle. You will also increase your flexibility and reduce your chance of injuries.

Sound too good to be true? Read on and in this guide I’ll explain what the best time to work out is based on your personal circadian rhythm.


Circadian rhythm 101

Your circadian (sir-kay-dee-an) rhythm is a daily cycle of biological activity. The biological activity with the most obvious circadian rhythm is your sleep-wake cycle. Think of your body as having an internal clock that regulates when to activate every system. Actually, the part of your brain called the suprachiasmatic nucleus (SCN) has built-in molecular oscillators that function very much like a pacemaker. That’s why the SCN is often called your internal or biological clock. The SCN interacts with virtually every major system in your body, including hormone production and central nervous system activity. Look at the image below for examples of biochemical and physiological events with a 24 hour biorhythm. [1]


24 Hour Human Circadian Rhythm


Note that the clock times are relative to your lifestyle and environment, most importantly when you sleep, work and see daylight. Think of the clock times as averages for a regular Joe in the US that works 9 to 5 and sleeps 12 to 8.


The T/C ratio and maximum anabolism

For athletes, systematic daily variations in core body temperature, energy metabolism and hormonal milieu are the most important factors influenced by your circadian rhythm. Let’s first look at testerone, the alpha hormone, and cortisol, the stress hormone.

As you can see in the graphs below, testosterone production is high at night and low during the day [2].


 Testosterone circadian rhythm


Cortisol output is low at night, rapidly rises during awakening and then gradually decreases over the course of the day [3].


Cortisol circadian rhythm


The testosterone to cortisol ratio or the T/C ratio is commonly used as a marker of tissue anabolism and a measure of overtraining [1, 7]. As you can extrapolate from the above graphs, the T/C ratio is highest in the afternoon and evening [17, 4, 29]. During this period, exercise causes the smallest increase in cortisol and the largest increase in testosterone [17, 1]. Cortisol elevation also recovers fastest at that time [5]. It is very plausible that the hormonal milieu in the late afternoon is optimal for maximum muscle anabolism. However, the research is still contentious about how transient fluctuations in hormone concentrations relate to muscle growth [4, 6, 29].

Regardless of whether hormones are related or not, muscle hypertrophy signalling is much higher in the afternoon than in the morning according to gene expression and cellular activation research [28].


Technical note for the hardcore science lovers

The specific factors involved in the higher muscle hypertrophy signalling in the afternoon appear to be the eukaryotic elongation factor protein (eEF2 (Thr56)) and the alpha and beta isoforms of mitogen-activated protein kinase (p38MAPK (Thr180/Tyr182)). The higher activity of eEF2 increases protein synthesis translation elongation capacity. The higher activity of p38MAPK increases cellular growth and differentiation to adapt to the training stress. Akt (Ser473), p70S6 (both Thr389 and Thr421/Ser424), rpS6 (Ser240/244), and Erk1/2 (Thr202/Tyr204) do not seem to be differentially responsive at different times of day.


Core body temperature and maximum performance

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. Core body temperature is low at night, rises quickly upon awakening and reaches a maximum in the evening (see graph below [8]).


Core body temperature circadian rhythm


Just hot enough to break a world record

The optimal body temperature for strength training normally occurs in the late afternoon to early evening. During this time, you have optimal nerve conduction velocity, joint mobility, glucose metabolism and muscular blood flow. This improves tissue stress distribution, so that your muscles can be maximally activated and your connective tissue remains healthy. [1]

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].


Derek Poundstone Record


The best time to work out

Based on the circadian rhythm of your hormones, gene expression and your core body temperature, the best time to schedule your training sessions is usually between 14:30 and 20:30 h [11]. If your sessions last longer than an hour, train a bit earlier. This advice is based on the assumption that you generally sleep when it’s dark and are awake when it’s light outside.

For those with an irregular sleep-wake cycle (read: students), it’s preferable to wait at least 6 hours after awakening before training. The optimal training time will then be closer to 20:30 h than 14:30 h.


Tweaking the formula

Individuals differ in the exact timing of their circadian rhythm [15]. The acrophase, or peak performance time, also differs across biological activities. For example, swimming performance peaks a few hours later in the evening than most ground based activities [10]. Peak performance and exercise adaptations correlate strongly, so a good rule is to train when you personally perform best [19, 1]. Realize though that significant individual variation does not imply utter randomness. Starting your day with floor presses from your bed or planking yourself to sleep is not recommended.

When experimenting with at what time your performance is optimal, you can use your heart rate as a guideline. Resting heart rate and core body temperature are strongly correlated [22]. Therefore, the time of day when your resting heart rate peaks is often the best time to train. Oral or insulated axilla (under the armpit) temperature readings are too noisy to measure your circadian rhythm [23, 24]. The scientific gold standard is sticking a thermometer up your ass, but that’s probably reserved for the real die-hards. As some researchers put it, “Core temperature is often measured using a rectal probe, a thermistor inserted 10 to 12 cm [4 to 5 inches] past the anal sphincter. Participants are not always comfortable with this site […]” [24].


Note for older readers

Peak performance for strength training in middle aged adults occurs earlier than in adolescents. (In the temperature graph above, the black dots represent older subjects.) So, if you’re in your forties or beyond, you should train an hour or two earlier. [14]


No time for excuses

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.

Most readers of my articles are intrinsically motivated to constantly improve themselves, so I probably don’t have to tell you to prioritize training in your life. So what’s a Bayesian with a genuine scheduling problem to do? You have two options to train in the morning or at night without having your training sessions suffer much as a result.


Nothing like a pre-workout pre-workout

Option one to optimize training in the morning is consuming a caffeine based pre-workout stimulant. A dose of ~250 mg (3 mg/kg) caffeine raises neuromuscular readiness to perform close to afternoon levels [16].

Note that the researchers of that study concluded that caffeine was sufficient to fully counteract impaired performance in the morning. The AM plus caffeine group still performed worse than the PM group, but this difference was not statistically significant. I suspect this was due to the small sample (N = 12) and resulting insufficient statistical power to detect the performance decrement.

Even aside from the fact that caffeine is not sufficient to boost your physical state to afternoon levels, there are several reasons why taking caffeine in the morning as a pre-workout is not ideal.
• Caffeine decreases the T/C ratio [16].
• Caffeine doesn’t elevate morning growth hormone levels to afternoon levels [16].
• If you consume more than 50-100 mg of caffeine daily, you’ll develop a tolerance to caffeine’s ergogenic effects.

Consuming caffeine at night will interfere with your sleep, so either way caffeine use is a temporary solution. All in all, caffeine supplementation is highly beneficial when training in the morning, but it’s still not as optimal as training in the evening (and possibly still using caffeine).


When doing it wrong, consistency is key

The second strategy to increase your performance when training at a suboptimal training time is to always train at that time. Your body will adapt its circadian rhythm to the morning training stress and reduce the performance decrement at that time [5, 20].

However, this adaptation is imperfect for two reasons. The body only adapts if you train at a time that is several hours removed from your physically optimal training time. Otherwise there is no incentive for the body to adapt its circadian rhythm [5, 20].

Secondly, the adaptation is incomplete [21]. The nervous system adapts reasonably well, but physiological systems such as hormone production adapt less well. Several studies have looked at long term muscle size and strength gains in groups training at different times of day. Even when people always train at the same time, strength increases are generally slightly higher and muscle gains up to 84% higher have been found when training in the evening instead of the morning [see graph below; 26, 27, 31, 32].


Best time to work out AM vs PM

Unpublished research from professor Scheett at the 2005 NSCA conference came to the same conclusion [30].


AM vs PM Scheett study results


Your body also acclimates to training in the early evening by increasing the circadian variation in performance throughout the day [25]. As such, it is still best to train when your body is biologically primed to do so, because you’ll prime it even further to train at this time. I incorporate meticulous circadian rhythm control in some of my clients and myself and even after supplementation, light therapy and nervous system activity control, we experience better results when consistently training in the early evening instead of in the morning.


The exception to the rule

If you have a job that is particularly stressful, it may be better to train during lunch than after work. Mental stress, such as very high responsibility or long commuting and physical stress, such as manual labor or simply working long hours, takes its toll on the body. The fatigue from work may then offset the benefits of the optimal physical state later in the day. At least one study shows that in shift workers peak performance occurs before work, followed by lunch, followed by after work [18]. So if your work is particularly fatiguing, it may be best to schedule all your training sessions before work or during lunch. Don’t forget to take a pre-workout. Training in the early morning before going to work will take some getting used to.



Not many people think about when the best time to train is. Even fewer have the discipline to schedule their training sessions when they are biologically primed for maximum performance. It’s a shame to put in countless hours in the gym at a time when your body is not in top gear and can’t recover optimally from the training. By following this guide you can optimize your training schedule and fast-track your gains. All without training more or changing your diet.


Take home messages

• Your circadian rhythm is a 24 hour cycle of biological activity set by your internal clock. Your sleep-wake cycle is one of many systems influenced by your circadian rhythm.
• Your hormonal milieu, gene expression and core body temperature have a circadian rhythm. Together, they result in peak physical condition to train and recover in the late afternoon to early evening.
• The best time to work out is generally between 14:30 and 20:30 h if you have a regular sleep-wake cycle.
• You can determine the optimal time to train by monitoring your maximum resting heart rate and training performance.
• If you can’t train when your body is primed to do so, supplement with caffeine pre-workout and schedule your workouts when you can always train.



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2. Pre-analytical issues for testosterone and estradiol assays. Raff H, Sluss PM. Steroids. 2008 Dec 12;73(13):1297-304.
3. M. Debono et al.: J Clin Endocrinol Metab 94:1548–1554, 2009 (48).
4. Hayes, L. D., Grace, F. M., LonKilgore, J., Young, J. D., & Baker, J. S. Salivary hormone response to maximal exercise at two time points during the day. Sport SPA Vol. 10, Issue 1: 25-30.
5. Erdemir, I., & Bozdogan, T. K. (2013). Effects of Exercise on Circadian Rhythms of Cortisol. International Journal of Sports Science, 3(3), 68-73.
6. Postexercise hypertrophic adaptations: a reexamination of the hormone hypothesis and its applicability to resistance training program design. Schoenfeld BJ. J Strength Cond Res. 2013 Jun;27(6):1720-30.
7. Duclos M. (2008). A critical assessment of hormonal methods used in monitoring training status in athletes. Int. J. Sports Med. 9:56–66.
8. . Duffy JF, Dijk DJ, Klerman EB, Czeisler CA. Am J Physiol. 1998 Nov;275(5 Pt 2):R1478-87.
9. Atkinson G. (1994). Effects of age on human circadian rhythms in physiological and performance measures. Liverpool: John Moores University.
10. Kline CE, Durstine JL, Davis JM, Moore TA, Devlin TM, Zielinski MR, Youngstedt SD. (2007). Circadian variation in swim performance. J. Appl. Physiol. 102:641–649.
11. Reilly T, Atkinson G, Edwards B, Waterhouse J, Farrelly K, Fairhurst E. (2007). Diurnal variation in temperature, mental and physical performance, and tasks specifically related to football (soccer). Chronobiol. Int. 24:507–519.
12. Sedliak M, Finni T, Peltonen J, Hakkinen K. (2008). Effect of time-of-day-specific strength training on maximum strength and EMG activity of the leg extensors in men. J. Sport Sci. 26:1005–1014.
13. Souissi N, Souissi M, Souissi H, Chamari K, Tabka Z, Dogui M, Davenne D. (2008). Effect of time of day and partial sleep deprivation on short-term, high-power output. Chronobiol. Int. 25:1062–1076.
14. Myers BL, Badia P. (1995). Changes in circadian-rhythms and sleep quality with aging—mechanisms and interventions. Neurosci. Biobehav. Rev. 19:553–571.
15. Drust B, Waterhouse J, Atkinson G, Edwards B, Reilly T. (2005). Circadian rhythms in sports performance—an update. Chronobiol. Int. 22:21–44.
16. Caffeine ingestion reverses the circadian rhythm effects on neuromuscular performance in highly resistance-trained men. Mora-Rodríguez R, García Pallarés J, López-Samanes Á, Ortega JF, Fernández-Elías VE. PLoS One. 2012;7(4):e33807.
17. Influence of circadian time structure on acute hormonal responses to a single bout of heavy-resistance exercise in weight-trained men. Bird SP, Tarpenning KM. Chronobiol Int. 2004 Jan;21(1):131-46.
18. Husmer HN (2013). The Effects of Time of Day on Resistance Exercise
Workout Responses. DigitalCommons@UConn.
19. The effects of circadian rhythmicity of salivary cortisol and testosterone on maximal isometric force, maximal dynamic force, and power output. Teo W, McGuigan MR, Newton MJ. J Strength Cond Res. 2011 Jun;25(6):1538-45.
20. Effect of time-of-day-specific strength training on serum hormone concentrations and isometric strength in men. Sedliak M, Finni T, Cheng S, Kraemer WJ, Häkkinen K. Chronobiol Int. 2007;24(6):1159-77.
21. Edwards, B., Waterhouse, J., Atkinson, G., & Reilly, T. (2002). Exercise does not necessarily influence the phase of the circadian rhythm in temperature in healthy humans. Journal of sports sciences, 20(9), 725-732.
22. Waterhouse J, Edwards B, Mugarza J, Flemming R, Minors D, Calbraith D, Williams G, Atkinson G, Reilly T. (1999). Purification of masked temperature data from humans: some preliminary observations on a comparison of the use of an activity diary, wrist actimetry, and heart rate monitoring. Chronobiol. Int. 16:461–475.
23. Sund?Levander, M., Forsberg, C., & Wahren, L. K. (2002). Normal oral, rectal, tympanic and axillary body temperature in adult men and women: a systematic literature review. Scandinavian journal of caring sciences, 16(2), 122-128.
24. The circadian rhythm of core temperature: origin and some implications for exercise performance. Waterhouse J, Drust B, Weinert D, Edwards B, Gregson W, Atkinson G, Kao S, Aizawa S, Reilly T. Chronobiol Int. 2005;22(2):207-25.
25. The effect of training at a specific time of day: a review. H Chtourou, N Souissi – The Journal of Strength & Conditioning Research, 2012 – LWW.
26. Time specific strength training induced hypertrophy and muscle strength increase of young untrained men. Laczo et al. 7th International Conference on Strength Training, 2010.
27. Effect of time-of-day-specific strength training on muscular hypertrophy in men.
Sedliak M, Finni T, Cheng S, Lind M, Häkkinen K. J Strength Cond Res. 2009 Dec;23(9):2451-7.
28. Acute responces in muscle hypertrophy signalling to a morning vs. afternoon resistance exercise protocol. Sedliak et al. 7th International Conference on Strength Training, 2010.
29. Hayes, L. D., Grace, F. M., KilgoreJL, Y. J. D., & Baker, J. S. (2012). Diurnal variation of cortisol, testosterone, and their ratio in apparently healthy males. Sport SPA, 9(1), 5-13.
30. Scheett, T. Effect of training time of day on body composition, muscular strength and endurance. National Strength and Conditioning Association Annual Conference, 2005, Las Vegas, Nevada.

31. Malhotra, D., Narula, R., Zutshi, K., Kapoor, G., & Aslam, B. (2014). Effect of Time of Day and Concentric or Eccentric Strength Training on Muscle Strength. Indian Journal of Physiotherapy and Occupational Therapy, 8(1), 134.
32. Effects of morning vs. evening combined strength and endurance training on physical performance, muscle hypertrophy and serum hormone concentrations. Ms. Maria Küüsmaa, Dr. Moritz Schumann, Dr. Milan Sedliak, Dr. William J Kraemer, Prof. Robert U Newton, Mr. Jari-Pekka Malinen, Dr. Kai Nyman, Prof. Arja Häkkinen, Prof. Keijo Häkkinen. Applied Physiology, Nutrition, and Metabolism, 0, 0, 10.1139/apnm-2016-0271.


  1. Jay says:

    It was a long wait, but is was worth it. Please post more though lol

  2. Mynameis says:

    This. This is the website I was waiting for. Articles about bodybuilding(and fitness?) with referenced sources. Thank you very much. Please keep going. As a suggestion, I would really like to learn something about training frequency.

  3. Wazzup says:

    Even when people always train at the same time, strength increases are generally slightly higher and muscle gains up to 84% higher have been found when training in the evening instead of the morning [see graph below; 26, 27].

    What graph ?

  4. B1nh says:

    Was a lonnnngggg wait. When is your book out Menno?

  5. David says:

    I’ve been checking every certain time, I’m not disappointed!

  6. Jake says:

    Menno, do you have any general opinions on nutrient timing, in regards to macro-nutrient ratios and caloric portioning according to circadian/biorythmic patterns? I know you associate with Borge Fagerli, who advocates the “Biorythm diet”, which I am familiar with. Do you recommend something similar?
    And, more specifically: Is there a significant benefit to putting the bulk of carbs, and calories, in the post-workout meal, rather than spacing carbs and caloric portions more evenly throughout the day?

  7. Luke says:

    Wow, that was a loooong wait, but well worth it. Always nice to read you’re doing something right :D Good to have you back!

  8. iori says:

    Sir i work at night from 20:00 to 05:00 and i work out 5:00 to 7:00 on weekdays and but this change on my last work out day which is on weekend I work out 18:00 after i wake up is this ok

    • So on weekends your sleep-wake cycle takes a complete 180? That’s definitely not conducive to your health or progress in the gym. If it’s socially impossible to maintain a somewhat consistent sleep-wake cycle, use the following techniques to manipulate your circadian rhythm:
      – Take melatonin before bed.
      – Take caffeine pre-workout (if it doesn’t interfere with your sleep).

      – Make sure your bedroom is pitch black.
      – Use full spectrum light therapy when you wake up.

      You’ll have to either force your body into a new rhythm every weekend or limit the shift away from your weekday rhythm on the weekends.

  9. Jimbolalo . says:

    The only thing with this logic, is the fact that some individuals would have their Circadian Rhythm shifted if; A. (they intermittent fast in the morning,) and or B. (They stay up late/sleep late).

    • Both do influence your circadian rhythm, yes.

      • Andrew says:

        Thank you for this article!
        I only eat 2 meals a day. I eat meal 1 around 10-11 pm (trying to get more consistent) and the last meal from 4-7pm.

        “Both do influence your circadian rhythm, yes.”
        What does this mean to me? Someone who does not have any food for 15+ hours a day. (I hear intermittent fasting is great for muscle growth, as the human growth hormone is boosted while fasting)

        Been working out in mornings.

        Does nocturnal training still apply to me??

  10. Theo R. says:

    Great Article Menno. Just confused about something. You indicate that testosterone is highest at night but based on the graph, it shows it to be highest at 6:00 am in the morning.

  11. atac says:

    My question is who this is intended for specifically. I think you have written an impressive, accurate article, but I think this article is a little more limited than it first seems. As weird as it might sound, not everyone is looking for maximum power/performance/strength from their workout, but to maximize the amount of metabolic (specifically catabolic) effect their workouts have. I’m speaking specifically of those that are trying to lose weight. With that in mind, do you think this article could be renamed and refocused for the population that has disease (obesity in particular) as their main goal? I have lived under the assumption that working out earlier in the day is better for that population because they are giving themselves more time in the day for their body to “run” at its highest rate working back toward homeostasis and, thus, more calories burned. What’s your opinion? Don’t let it be lost that I thoroughly enjoy your site and perspective.

    • Good point. My articles generally assume, unless explicitly stated otherwise, that someone’s goal is maximum progress as a bodybuilder. In this case, this holds true for fat loss as well. You burn more fat and you have better endurance in the PM than in the AM. Post-workout energy expenditure (excess post-exercise oxygen consumption) is also higher then, because it is a result of the intensity of the session.

      • atac says:

        Right. Duh… apologies. I hadn’t looked around enough, but clearly that’s the case. However, I still need help understanding how EPOC is not affected if the time between the end of the workout and sleep is shortened. Is it that EPOC is more or less put on hold until the morning on waking up and there is essentially no measurable difference?

        • EPOC is mainly affected by pre-workout nutrition and only marginally by nutrition several hours after a session. Either way though, EPOC generally amounts to less than a 100 kcal per session, so it’s almost irrelevant. Weight training doesn’t burn that many calories. The main long term metabolic effects are those of increased protein turnover.

  12. TravisRetriever says:

    The testosterone being so high in the morning might also explain the “exercise as soon as you get up on an empty stomach” being so common.

  13. TravisRetriever says:

    “The testosterone being so high in the morning might also explain the
    “exercise as soon as you get up on an empty stomach” being so common.”
    Was my comment. Wouldn’t let me comment before when logged in for some reason. O_o Oh well. So yeah, thanks for this website. It has been very helpful just in the day or two since I found it. :)

  14. Lea says:

    I am working on my website and have a section on fitness. I would like to put this link on there for people to read your article. Very well done. Would that be ok with you? I also have a question for you. I’m 51 and find that my best runs are in the morning before I eat even though that goes against the findings in this article. (if I understood it correctly) I have flexibility in my schedule so when would you suggest that I run? Maybe it’s just habit because that’s when I’ve always run. Open to suggestions!

    • Do you want to link to my website? That is always fine. Or do you want to put my article on your site? That is also possible if you include a link plus an about the author section. You can email me about that or ask me here to email you.

      As for your question, what is the goal of your morning run? If it’s performance, in the evening as per this article would work best. If it’s fat loss, any time after your first meal of the day is fine, but I’d recommend reading my article about cardio (see training section) if you haven’t yet.

  15. Does this also apply to people who are cutting and who want to maintain as much lean body mass/muscle mass as possible?

  16. So if you do workout in the early morning, say 6am, then how does that affect your hormones/circadian rhythm throughout the day? Because don’t your hormones change after you workout?
    Is working out in the morning more for cutting/leaning out?

    • Cutting also benefits from training later in the day through the same mechanisms. What happens to your hormones post-workout will be a mixture of the circadian rhythm effects and the training effect.

  17. Gannicus says:

    Menno, just happened upon your website and absolutely love it. Thanks for sharing the knowledge you do.

  18. Matti says:

    Hey Menno,

    Good to see that you’re bringing some evidence-based thinking into the sport!

    In this article you propose that training between 14:30 and 21:00 is optimal.

    Besides reasoning you also say there is empirical evidence:

    “Even when people always train at the same time, strength increases are generally slightly higher and muscle gains up to 84% higher have been found when training in the evening instead of the morning [see graph below; 26, 27].”

    When I checked both sources [26,27] however, both say there was no statistical difference between the morning and afternoon training groups.
    Where did you find the graph? Is there anything I’m overlooking?

    Just asking out of interest cuz I like the debate on these interesting issues :)

    • I suggest rechecking the sources because although the difference did not reach statistical significance in their first study (lack of power likely), it did in the second and that’s where the graph is from.

      • Matti says:

        Aha…yeah I found it.
        The second article does indeed find a difference.

        They differed their experimental setup:
        In the first study the subjects underwent a 10-week training phase before splitting in morning and afternoon groups, whereas in the second study there was no training phase.

        The second study only uses 5 subjects in the morning and 5 in the afternoon group. And they’re students. So training at 7:30 am will probably mean that the morning group slept significantly less than the afternoon group.
        At the end of the article they comment that they would like to do a follow-up study with more subjects and training sessions. I think that would be very interesting.
        If they do, keep me updated :)

  19. Renee says:

    Wow that was strange. I just wrote an incredibly long comment
    but after I clicked submit my comment didn’t appear. Grrrr…
    well I’m not writing all that over again. Anyway, just wanted to
    say excellent blog!

  20. dj says:

    Hey Menno so although one must consider individualization.. In general if one is already very lean, and no longer wants to count macros or calories due to the stress, to keep making progress without going off the what would be the optimal amount of times per week to exercise? Like how often do your programs usually prescribe? Many seem to be on the notion that minimal is best but I find that hard to accept being passionate about bodybuilding that would be optimal.

  21. Oliver says:

    Hey Menno, I discovered your site some days ago and I really like the artiles I have read and I’m looking forward for the coming ones!

    I’d like to know in how far intermittent fasting influences the “best time to work out”. In the past I used to work out in a fasted state and had my first meal of the day directly after training around 12.
    So should i keep to your article and work out later?

  22. Rudy says:

    Good read Menno, I’ve always been an advocate of late afternoon / early evening training if it suits people’s lifestyle. Do you think steady state in the morning is significantly superior for contest prep due to higher cortisol levels? Thanks

    • No, it’s not. You won’t burn more calories and nutrient partitioning isn’t better either, so there’s no mechanism by which morning cardio would outperform later cardio, hence research finding no difference in this regard.

  23. Loola says:

    After reading your shares have been many lessons learned for myself I was looking for this information for quite some time and today I found your website I was a bodybuilding athletes want retrieval of information to gain experience.

  24. Gilles says:

    Kind of a dumb question but you say, “As you can see in the graphs below, testosterone production is high at night and low during the day.”

    Looking at the graph I just don’t see it, I see highest testosterone at around 8:00, around 22nmol/L four younger and lowest at 20:00 at 14nmol/L. So the opposite of what you say, or am I reading the chart wrong.

  25. mahjong says:

    Wonderful blog! This is very informative site. I am totally pleased by your excellent work. Many thanks for sharing.

  26. agario says:

    In your blog I was happy to see your article, better than last time, and have made great progress, I am very pleased. I am looking forward to your article will become better and better.

  27. It seems hard for a common official worker dreams about muscle :p

  28. No, it’s not. You won’t burn more calories and nutrient partitioning isn’t better either, so there’s no mechanism by which morning cardio would outperform

  29. I have searched a lot of information in this article. I began to do a page, i hope it is soon completed. People can visit and comment, thanks.

  30. AK says:

    Nice article. I used to lift weights in the late afternoons or evening, people noticed me getting bigger. But I heard good things about lifting early morning so did this for 3 months at 5am, thinking that would be best due to eating throughtout the day. I lost weight but remind lean but too skinny. Poor results. Now going back to lifting in the late afternoon and/or evenings.

    • Nice to hear from someone who actually tried it! Most people never do.

      • Erik says:

        Hey Menno,

        I actually have trained like this (05am -07 am) for 6 months approximately. This has lead me to a pretty unhealthy CR, where I easily can wake up 03 am in the morning without getting back to sleep. I suspect it has to do with high cortisol levels or something, as my body “prepares” for high stress.
        I now want to do the change to afternoon workouts. Any tips for making the transition easier? I simply am not at “top” in the evening yet (tired, lack of concentration etc) but I guess it will take some adaption time.

  31. Nice article. I used to lift weights in the late afternoons or evening, people noticed me getting bigger

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  38. Chen.D says:

    this is realy bad news for me, im a student and i can train only in the morning also in my gym there is only one rack and afternoon its impossible to squat there.
    what do you think about go to sleep earlier, lets say at 20:00 and to wake up at 04:00 and to workout at 08:00 after esspresso, 2 cubes of 90% dark chocolate with 2 tbsp of Coconut oil as pre-workout? btw your website is awsome and i love that you give refrences to each article.

    • Alberto says:

      My partner and I get up at 3:30 am M-F and are at the gym by 4 am, and work out for about one hour and 15 minutes.

      We are very strong at that time of the day (Maybe the high Testosterone levels); our workouts are very productive.

      We do go to bed by 7:30 pm, so we do get the 8 hour sleep.

      We are not the regular ‘Joes’, but I think the body does work with you and the hormone cycles adapt to your schedule.

      Before workout, we take a mix of juice and whey protein along with a cup of coffee.

      I just wanted to share this info. Not a true believer that the PM workout is the best for you.:). I find that body is still digesting Bf, Lch and and snacks. Really hard to work out abs.

      Give it a try, early workouts are the best.

      Thank you

    • You can advance your circadian rhythm, yes, and see the sections on caffeine use and morning training.

  39. Blue says:

    Here is the thing about picking a side to this argument. (1) The evidence provided does and does not back it up one way or another, and also permits the argument for several different times of the day as being ideal for workouts if we use the authors logic of T/C ratio (e.g. early AM, late night, etc. would work too), and (2) Providing scientific evidence is meaningless if what you are saying does not match up with the information provided. I see some very fundamental challenges in the argument about best workout time presented here. According to the graphs both Testosterone (T) and Cortisol (C) are at their highest serum levels (taken from blood samples) in the morning. The author fails to interpret the times presented in the graphs correctly and makes the fallible argument that the graph shows that T is highest at night and lowest in the morning. That the secretion of T is at its highest in the morning backs evidence that its use in the body could be benefit to an early workout. One question that remains is: If T/C ratio is generally used to measure overtraining in the academic literature, how can we extrapolate the information in the charts, which are measured on two totally different scales to discuss an argument about time of day to exercise? The logic needs to be better understood by the reader. Another thing that influences workout times is sleep, our sleep/sleepiness schedules sometimes go against our circadian rhythms. Many people over the age of 5 or 6 in America do not get siestas or mid-day naps. The afternoon slump, which directly conflicts with the earlier end of the ideal times proposed by the author is brought on by our body trying to maintain its homeostatic and metabolic systems, and people get tired at this time (try teaching a class between 2pm (14:00) and 4pm (16:00), and you’ll see what I mean). Another question is: Are you at your optimal training when you are sleepy? What that means is that the picture of ideal exercise time is more holistic than circadian rhythms and body temperature presented by the author. With regards to body temperature, our bodies have generally evolved to respond to diurnal patterns of behavior, when sleep happens at night and wakefulness occurs in the day. It makes sense that your body temperature would increase as some of our regulatory functions decrease. This maintains metabolic homeostasis but it should not be a deciding factor to when you should exercise. In addition, the body temperature argument needs to be clarified because our body temperatures maintain homeostasis within .5 degrees Celsius (.9 degrees Farenheit, which by the way is what the graph is showing). I would not make a jump to say that this has a maximal impact on our workout results. With that evidence we can extrapolate an argument that optimal daily times for exercise may be different for males, ovulating and non-ovulating females due to circamensal differences in rhythms. Basal temperatures are higher for females after menstruation. But the author does not provide evidence about gender differences and I am not aware of any studies to support a supposition about gender difference based on body temperature differences. Cell signalling (muscle hypertrophy signalling) is another thing that is related to homeostasis (it allows for the development, repair, and is a part of normal muscle tissue homeostasis), however, the author does not provide the evidence that time of day of exercise significantly impacts muscle hypertrophy signalling (but merely that it occur more in the evening). Therefore it seems like reaching to correlate the signalling with an optimal time to exercise. Question: Would exercising in the evening have the propensity to increase muscle hypertrophy signalling at a greater rate than would exercising at another time of the day?

    All of these unanswered questions leads me to my conclusion: There are so many factors in an individual that impact when exercise is ideal.

    I would propose another alternative to the author’s proposition, work out the times that are optimal for your body. Figure those things out based on your own personal patterns of activity, sleep, and wakefulness. Your body should be able to tell you when you should work out, irrespective of what any expert says. If you follow a diurnal pattern of sleep-wakefulness, you might find that there is more than one time period during the day that exercise would be optimal. Individual differences are important when deciding what pattern works for you and what fails to be reported in most of the research cited here are individual differences.

    Granted, I was searching for some evidence to help me choose some ideal times for exercising throughout the day based on my work schedule. However, after reading the post I have made my decision to conduct my own research because the convergence of evidence I found here does not seem to support the overall supposition.

  40. Sunil Kumar.V says:

    Good blog. it is always better to do exercise in the evening due to several factor. exercise in the morning will drain your energy and you will feel lethargic throughout the day. you will feel sleepy when you try to read a book or watch tv. but if you do it in the evening your body will naturally refresh during the sleep and you can wake up refreshed and full of energy.and it is important not to skip or delay the break fast as your calories are used and your cells are starving for energy in the morning after the sleep.

  41. Nice article. I used to lift weights in the late afternoons or evening, people noticed me getting bigger. But I heard good things about lifting early morning so did this for 3 months at 5am, thinking that would be best due to eating throughtout the day. I lost weight but remind lean but too skinny. Poor results. Now going back to lifting in the late afternoon and/or evenings.

  42. I do not know if it’s just me or if perhaps everybody else experiencing problems with your site.

    It appears like some of the text on your content are running
    off the screen. Can somebody else please provide feedback and let me know if this is happening to them as well?
    This might be a problem with my web browser because I’ve had this happen before.
    Many thanks

  43. The optimal time of day to train is not usually something that people think about. People train when it’s convenient, when they feel like it, when they can. As a result, the decision on when to train is a byproduct of other arrangements. Such a second rate approach to planning your training sessions leads to second rate results.

  44. TJ says:

    Hi Menno,

    Amazing information and thank you for sharing. I have one query regarding this. I have been working in night shift for 2 years. I sleep at 8am and wake up at 4pm. If I am understanding it correctly, my body clock is reset according to this schedule. what would be the ideal time for me to workout to gain maximum results. Please advice.

    Thank you

  45. Kevin Indig says:

    Hey Menno,

    thanks for the great article! I was wondering how to structure training when doing double sessions (one in the early morning, around 6:30AM, the second around 5PM)? Is there potential for optimization or does it not matter at this point?


  46. Ben says:


    Between working out “too late”, say from 8pm to 9:30pm and working out in the morning with caffeine pre-workout, which would be the most optimal?

    Thank you

  47. Nice information shared. i have time for workout only in evening.

  48. Mike says:

    I’m seeing that the highest secretion of testosterone is at 9am, so one hour after awakening. Then shouldn’t we enjoy this peak of testosterone to train in that time?

  49. Nikola says:

    Hi,I’ve found this article by coincidence and I can say that it’s great. Finally some article about this subject with sense science background.
    However,you could do some research about,not only working or sleeping irregular,but working rotational 12-hour shifts…. Its really hard,but I try to obtain everything I can -meals,training,rest (sleep) etc., with all the things I have to do,and its not only grocery list and preparing meals – which is not easy and its time consuming by itself…:)
    Job can be hard,stresfull ,but even if its sitting almost all day long its still long hours,early awakening and/or possible lack of sleep. I try to do effective and intensive,still quite explosive workouts,mostly upper/lower style,but sometimes “Arnold” or “old school style” – chest/back,shoulders/arms,legs split and before that I really liked full body training,I was really into it,but intensive,explosive,hypertrophy-strenght and functional hypertrophy based workouts are much better for me. I would add,its mostly after-work training or “day off” (if you can call that day as such) because it would be too much before work (I have to be awake in about 5 or 6 AM) and there is no open gym in that hours anyway and unfortunately,lunch hour or afternoon is not an option as well (I know it would be the best,but job doesnt allow that).
    What is the best way or concept,in general,of doing everything “right” and most effective in this case…

    • Shift work is very tricky. In my clients I generally go with one of the following options when possible:
      A) Find times when you can be regular in your schedule, even if it means sleeping and being awake at unconventional times.
      B) Drastically shift your biorhythm at each scheduling change with meticulous biorhythm control (light therapy, melatonin, caffeine use, etc.).

      • Nikola says:

        Thank you very much on your answer… I am really trying to obtain everything as much as regarding not only workouts,but groceries and meals too… Its really hard cause I have to do everything by myself,but I am really trying,not letting anyone to put or drag me down,cause there is little or no understanding for consistency,commitment,will,effort to archive something,discipline,striving for better something for self-improvement etc.
        I am already “experimenting” with workouts before night shift and coffeine/melatonine combination,but some kind of better environment or better job would be much better option,we’ll see….:)
        Thank you on your answer and your site. Greetings from Novi Sad,Serbia.

  50. Cal says:

    Hi Menno,

    I really enjoyed this article. I was wondering if I were to get up at 8:30 AM everyday, but only have an opportunity to train after 8 PM, would it still be optimized to train at that time?

  51. Shane says:

    I’ve never heard the benefits of a lunchtime workout explained that way, and it really makes sense. I wouldn’t consider my job particularly stressful, but I think I use so much mental energy that if I train after work, I’m a little drained. But if I’m training on a non-workday, training in the evening is no problem.

  52. really good you share this article gives a good understanding of the journal to me that they learn to form an athletic body.

    Honestly athletic body is my dream since the first, unfortunately, will not materialize

  53. Togay Koç says:

    Just started getting into your material. I find it very interesting, well researched yet practical.
    Depressing article for me though as scheduling means that I have to do my training in the mornings. Would you say pre/intra- workout nutrition needs to be adjusted based on early morning training sessions? Any advice on interval between waking and beginning training? (I guess the appropriate question would be what is least sub-optimal, given that training in the morning is suboptimal any way).
    Thanks for the great content

  54. Jeff Emory says:


    Great Website. Very intriguing insights.

    I’m 42, in a very stressful job (although sedentary). I’ve been training for about 8 weeks now, Mon-Fri, from 11:00am to 12:00pm. All weight training. My sleep pattern is from 10:00pm to 7:00am. I have a spark (advocare) in the morning on my commute to work, and I do not eat breakfast during the week. The reason for the morning workouts, is because before starting my regimen, i would feel sluggish after lunch (about 2:30pm). If I move my workouts to after lunch, I would not train fasted. I don’t know how you feel about this approach. Do you have any articles about your research on Intermittent Fasting?

    Would you recommend any changes? Pre-workout meal instead of training fasted?


    • Hey Jeff, I’d have to do a full client assessment to provide sound advice here. There are too many factors to consider.

      I don’t have any articles on IF, but I’ve touched on it in a few interviews on the site.

  55. John says:

    Hi Menno,

    Excellent article as always.

    Question: If someone is on PED’s and TRT do you believe the limitations of working out in AM would be offset due to the PED’s allowing to workout in the morning?


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