Timing

What It Is

The time of day you train.

Why It Matters

Training in the morning and training in the evening may make little to no difference to strength, power, and hypertrophy. Two meta-analyses and one small trial each compared the same programme run at different hours and found no clear advantage either way, whichever time of day strength was tested afterwards. Read that as an absence of evidence for a difference rather than proof that none exists: the trials are small, the two reviews share some of the same underlying studies, and their strength evidence comes almost entirely from untrained men.

What does vary by the clock is performance on the day rather than adaptation over months. Maximal strength is reliably higher in the late afternoon and early evening than it is first thing in the morning. After a block of morning training that daily gap appears to close, while after evening training it persists, which researchers read as the body clock entraining to your training schedule. Treat that closing as a pattern rather than a settled rule: no trial has tested it head-on, and the nearest attempt was inconclusive for strength.

So pick the slot you can defend against the rest of your week, and treat consistency as the variable worth protecting. That afternoon peak is not in itself a reason to train in the afternoon: if mornings are what you can keep, expect the early sessions to feel weaker and your morning numbers to climb over the months that follow. If evenings are what you can keep, expect that to be where your best numbers sit.

• Grgic, J. et al. (2019). The effects of time of day-specific resistance training on adaptations in skeletal muscle hypertrophy and muscle strength: A systematic review and meta-analysis. Chronobiology International. doi.org/10.1080/07420528.2019.1567524
• Knaier, R. et al. (2022). Diurnal Variation in Maximum Endurance and Maximum Strength Performance: A Systematic Review and Meta-analysis. Medicine and Science in Sports and Exercise. doi.org/10.1249/MSS.0000000000002773
• Bruggisser, F. et al. (2023). Best Time of Day for Strength and Endurance Training to Improve Health and Performance? A Systematic Review with Meta-analysis. Sports Medicine - Open. doi.org/10.1186/s40798-023-00577-5
• McLeod, J.C. et al. (2023). The influence of resistance exercise training prescription variables on skeletal muscle mass, strength, and physical function in healthy adults: An umbrella review. Journal of Sport and Health Science. doi.org/10.1016/j.jshs.2023.06.005
• Dighriri, A. et al. (2025). The impact of the time of day on muscle and metabolic responses to resistance exercise in healthy adults: A randomised controlled trial. Experimental Physiology. doi.org/10.1113/EP093020