Morning or evening workouts: which is better for muscle?

Short answer

Consistency matters more than the clock. In 6–12 week studies, morning and evening training built similar muscle, and strength was highest at the time of day people trained.

Morning or evening workouts: which is better for muscle?
'Stronger in the evening → evening training builds more muscle' — does this hold?
Since weights feel easier in the evening, some say evening training builds more muscle. Others swear by fasted morning sessions. We checked studies that changed only the time of day.
Does strength really change across the day?
It does, people were stronger in the evening
An analysis that pooled 11 studies comparing only training time found that, before training began, people were stronger in the evening than the morning. But people who kept training in the morning brought their morning strength up to evening levels.
So does muscle grow more in the evening?
Morning 2.7%, afternoon 3.5%, no real difference
In a 10-week study where people did the same training in the morning (7-9 a.m.) or afternoon (5-7 p.m.), thigh muscle on MRI grew 2.7% and 3.5%. The 0.8% gap was not a meaningful difference. The 11-study analysis also found muscle growth was similar regardless of time of day.
Do recent trials agree?
No difference at 6 weeks or at 12
In a 2025 trial, 36 people lifted in the morning or evening for 6 weeks, and thigh muscle thickness and leg strength changed the same at both times. In a 2026 trial, 108 people trained for 12 weeks at either their personal strongest or weakest time of day, and strength and arm and leg muscle mass did not differ.
Did any study favor the evening?
One did, but only in the last 12 of 24 weeks
In a study where 42 people combined strength and endurance training for 24 weeks, muscle grew 12-20% in every group. But in weeks 13-24, the evening groups gained more muscle. A 2026 trial with 49 people doing similar training for 8 weeks found no consistent difference by time of day.
What matters more than the clock?
Strength showed up best at your usual training time
A 2023 analysis of 26 studies comparing training times found no time of day was better than another. Instead, effects were larger when training and strength testing happened at the same time of day. In other words, the body adapts to the time you train.
Bottom line: for muscle, the best time is the one you stick to
Matching a meet or test time is a bonus
Muscle grew about the same with morning or evening training. Strength showed up best at the time people usually trained. So picking a time you will not skip is enough, and if you have a competition or a max-out day, practicing at that time of day works.