The Best Time to Train for Maximum Muscle Growth (Morning vs Evening)

When it comes to optimising muscle growth, most lifters focus on factors like training volume, intensity, frequency, progressive overload and nutrition. However, one often-overlooked variable is training time. Does it matter whether you train in the morning or evening? Could one time of day give you a physiological edge in building muscle?

This article explores the scientific evidence comparing morning and evening resistance training, examining muscle hypertrophy, strength gains, hormonal responses, circadian rhythms, and practical considerations. The goal is to provide a clear, research-backed answer to help you maximise your gains.

Circadian Rhythms and Physical Performance

The human body operates on a circadian rhythm—a roughly 24-hour cycle driven by the brain’s suprachiasmatic nucleus. This rhythm influences many physiological processes, including core body temperature, hormone secretion, neuromuscular efficiency and even gene expression. Core body temperature tends to be lowest in the early morning (around 4–6 am) and peaks in the late afternoon or early evening (between 4–7 pm) (Chtourou & Souissi, 2012). This temperature variation affects muscle elasticity, enzyme activity and nervous system activation, all of which are relevant to exercise performance.

Numerous studies have shown that physical performance—particularly strength and power output—is typically higher in the late afternoon and early evening compared to the morning (Souissi et al., 2002; Sedliak et al., 2009). This suggests a potential advantage for hypertrophy training in the evening due to improved neuromuscular efficiency.

Hormonal Fluctuations Throughout the Day

Hormones play a key role in muscle hypertrophy. Testosterone and growth hormone are two major anabolic hormones that influence protein synthesis and muscle repair. Cortisol, a catabolic hormone, promotes protein breakdown and is generally considered detrimental to muscle building when chronically elevated.

Testosterone levels follow a diurnal pattern, peaking in the early morning (approximately 6–9 am) and gradually declining throughout the day (Cook et al., 2011). This has led some to suggest that morning training might be better for muscle growth. However, acute changes in testosterone around training sessions don’t appear to directly influence hypertrophy over time (West et al., 2010). Moreover, cortisol also peaks in the morning and drops throughout the day, potentially creating a less favourable anabolic environment early in the day.

Growth hormone tends to spike in response to sleep and is more strongly linked to recovery than training time per se. Therefore, while hormonal fluctuations exist, their practical impact on hypertrophy seems marginal compared to mechanical tension, training consistency and total training volume.

Research Comparing Morning and Evening Training

Multiple studies have directly compared the effects of morning versus evening training on muscle strength and hypertrophy.

A study by Sedliak et al. (2009) followed men over 11 weeks of resistance training and found significantly greater strength gains in the evening training group. Both groups saw increases in muscle size, but improvements in neuromuscular performance were more pronounced in those who trained later in the day. A study by Chtourou et al. (2012) found that evening training led to greater improvements in maximal strength and muscle activation in trained males. Likewise, a 2016 study by Küüsmaa et al. showed that men who trained in the evening had better improvements in leg press and bench press strength compared to morning trainers over a 10-week period.

However, not all studies have shown major differences in hypertrophy. For example, a 2021 study by Schoenfeld et al. examined time-of-day training effects in young men and found no significant difference in muscle thickness after 10 weeks, although strength adaptations were slightly higher in the evening group. These findings suggest that while hypertrophy may be comparable across training times, strength development tends to be better later in the day.

Muscle Protein Synthesis and Training Time

Muscle protein synthesis (MPS) is the biological process responsible for muscle repair and growth following resistance training. Acute increases in MPS occur for up to 24–48 hours after training. While time of day may influence acute performance, the elevation in MPS post-exercise appears to be independent of training time, provided that total volume and intensity are matched (Baar & Esser, 1999). Furthermore, nutrient timing—particularly protein intake around training—may have a larger impact on MPS than the specific time of day one trains (Tipton et al., 2001).

Chronotype and Individual Response

One emerging area of research is the role of chronotype—whether someone is a “morning person” or an “evening person.” Chronotype influences alertness, mood, energy levels and performance rhythms. A 2015 study by Vitale & Weydahl noted that individuals perform better when they train at their preferred time of day. For instance, “morning types” may adapt better to training early in the day, while “evening types” might respond more favourably to late sessions.

This has important implications. Training at a time that suits your internal clock may enhance performance and adherence. In other words, the “best” time to train for hypertrophy might also depend on when you can consistently train hard, lift progressively and recover adequately.

Practical Considerations

In practice, the optimal time to train also depends on external factors like schedule, nutrition and sleep. Morning training may be more consistent for those with busy work schedules or family obligations. However, some people report feeling sluggish, less motivated and weaker in the morning, especially without adequate warm-up. Evening training, while potentially superior for strength and power output, can interfere with sleep if done too close to bedtime. High-intensity workouts increase adrenaline and body temperature, both of which can disrupt melatonin release and delay sleep onset (Oda & Shirakawa, 2014). Ideally, evening workouts should be finished at least 2–3 hours before going to bed.

Another factor is nutrition. Training in the evening usually allows for multiple meals beforehand, providing more available energy and glycogen. Morning training, unless fasted, may require waking up early enough to eat, digest and warm up properly.

Training Consistency and Long-Term Adherence

Ultimately, long-term progress in muscle hypertrophy is driven by consistency and progressive overload. A 2010 study by Aragon & Schoenfeld emphasised that adherence to a training programme is more important than minor differences in training variables like time of day. The best time to train is the time you can consistently commit to while maximising performance, recovery and nutrition.

Summary of Scientific Findings

1. Performance markers such as strength, power and neuromuscular coordination are typically higher in the late afternoon or evening, due to circadian-related increases in body temperature and neural activation.
2. While testosterone is highest in the morning, its short-term fluctuations have limited impact on long-term hypertrophy outcomes.
3. Cortisol peaks in the morning, which may reduce the anabolic environment relative to evening sessions.
4. Studies suggest that strength adaptations are superior in evening training, while muscle hypertrophy is relatively similar between morning and evening workouts, assuming volume and intensity are equated.
5. Individual chronotype and training preference play a substantial role and may influence adaptation and training enjoyment.
6. Sleep, nutrition and lifestyle factors may outweigh the marginal benefits of time-of-day training effects.

Conclusion

For maximum muscle growth, evening training appears to offer a slight physiological edge, particularly in terms of strength and power development. This is supported by improvements in neuromuscular efficiency, elevated core temperature and reduced cortisol levels later in the day. However, hypertrophy results themselves are not dramatically different between morning and evening sessions, provided training is consistent and of sufficient quality. More important than choosing a “perfect” time is choosing a time you can consistently train hard, eat well around and recover from effectively. Understanding your chronotype, aligning training with your schedule and prioritising recovery will have a greater cumulative impact than the clock on the wall.

Key Takeaways Table

References

Aragon, A.A. and Schoenfeld, B.J., 2010. Nutrient timing: the means to improved exercise performance, recovery, and training adaptation. Journal of the International Society of Sports Nutrition, 7(1), p.36.

Baar, K. and Esser, K., 1999. Phosphorylation of p70(S6k) correlates with increased skeletal muscle mass following resistance exercise. American Journal of Physiology-Cell Physiology, 276(1), pp.C120-C127.

Chtourou, H. and Souissi, N., 2012. The effect of training at a specific time of day: a review. Journal of Strength and Conditioning Research, 26(7), pp.1984-2005.

Cook, C.J., Crewther, B.T. and Smith, H.D., 2011. Comparison of baseline free testosterone and cortisol concentrations between elite and non-elite rugby union players. Journal of Sports Science & Medicine, 10(3), p.599.