The best time to work out: the one you can repeat

The best time to work out is the one you can repeat. Not the time someone online swears by, and not the time you'd pick in a perfect week: the slot your real week protects, three months from now.

That isn't a dodge. For strength and muscle, studies comparing morning and evening lifting find small differences or none, and the same studies give a good reason to keep the time steady once you pick it. This page covers what they say, how to pick your slot around work, classes and family, how to handle early mornings, and what to do when you work shifts.

Morning or night: what the research says

On any given day, most people are a little stronger later on. A 2022 meta-analysis found grip strength, jump height and power in a 30-second all-out cycling test were all higher in the late afternoon and early evening than at 8 to 10 a.m.; for grip strength, the difference was small to medium.¹

Stronger on the day isn't the same as building more over months. For that, studies put one group on morning sessions and another on evening sessions for weeks, then compare. Here's what they found:

• Strength and muscle grow about the same. A 2019 meta-analysis of 11 studies found strength gains were similar whether people trained in the morning or the evening, and so were gains in muscle size.²
• The big position stand agrees on strength. The American College of Sports Medicine's 2026 position stand found strength was not affected by morning versus evening sessions, and that there wasn't enough data to say whether time of day changes muscle growth.³
• No time of day wins outright. A 2023 meta-analysis of randomized trials found little evidence for or against any time of day being better for improving performance. In its pooled strength data, the differences between morning and evening training were small and not statistically significant.⁴

Two trials show what "about the same" looks like in numbers. In one small trial, untrained young men lifted twice a week for 11 weeks, either at 7:30 a.m. or at 4 p.m. Strength rose about 17% in the morning group and 15% in the afternoon group, thigh muscle grew about 9% and 12%, and the authors concluded similar strength and muscle gains could be reached at either time.⁵ In the other, young men did strength and endurance training in the same session for 24 weeks. Strength rose about the same in every group, but in weeks 13 to 24 the evening groups gained more muscle; the authors suggest time of day only mattered once training ran past 12 weeks.⁶

So if evenings have an edge for muscle, it's small, it showed up in one longer trial, and every group in these studies gained strength and muscle at whichever time it trained. One caveat: the 2023 review's pooled data came almost entirely from young men, and its authors caution against applying the results to women.⁴

Why keeping the same time helps

The research has one finding worth acting on: you may get better at lifting at the time you usually lift. In the 2019 meta-analysis, people were stronger in the evening before training started, but morning training could bring morning strength up to about evening levels, while evening training kept the usual gap.² The 2023 review found gains tended to be larger when people were tested at the same time of day they trained. For strength, that edge was small and not statistically significant.⁴

In practice: pick a time and keep it. If you lift early, keep lifting early: that's the habit behind the morning-strength finding. If you ever test a max or go for a personal record, do it at the time you usually train. And a fixed slot is easier to protect: "Monday, Wednesday and Friday at 6:30" is a plan; "sometime this week" isn't. (Why set days and times beat motivation.)

How to pick your slot

Start from the week you have, not from the clock. The right slot is the one that survives your worst normal week. When a client asks me what time is best, I ask which time they could still keep on a bad week.

• Before work. Nothing has gone wrong yet, so it's the slot least likely to get eaten. The cost is an earlier alarm, so it only works if your evening can end earlier too.
• Lunch. Fits a short session if the gym is close. Here's a thirty-minute one.
• After work. The time of day most people are strongest,¹ and the slot most likely to lose to a late meeting, the commute or dinner.
• Around classes. A class schedule is set for the whole term, so tie each session to a class. The college workout routine shows how.
• Around kids and family. Pick the slot someone else can cover, or the one before the house wakes up.

Then test it for two weeks. If you made every session, keep it. If you missed the same slot twice, the slot is wrong, not you: move it. Away on a trip? Here's a hotel workout. The ACSM stand says programs fitted to the person can help people start exercising and keep at it,³ and the time of day is part of the fit. Still choosing how many days? How often to train comes first.

If you train early in the morning

Most people are weaker in the morning than later in the day, so the first sets can feel heavy.¹ A longer warm-up is the usual fix: a 2021 systematic review of 49 studies found an extended morning warm-up was the most effective way to shrink the gap between morning and later-in-the-day performance.⁷ It doesn't always close the gap. In a study of ten trained men, a morning warm-up long enough to bring body temperature up to evening levels did not bring squat and bench press performance up to evening levels.⁸

So spend the warm-up on the lift itself. A review of time-efficient training found little support for a general warm-up when time is short, but says warm-up sets of the exercise can be useful, particularly before heavy loads.⁹ Two or three lighter sets of your first lift, building toward your working weight, do the job. Then:

• Expect the first working set to feel heavier than it would at 6 p.m. Judge effort by reps left, not by the number on the bar. (Here's how to judge reps left.)
• Switching from evenings? Your first morning sessions may run a little lighter. In the research above, morning training could bring morning strength up over the weeks, so give it time before you decide mornings don't work.²
• Compare like with like. Measure a 6 a.m. session against last week's 6 a.m. session, not against an evening one.

If you work shifts

The training studies in the 2023 review ran on day schedules: morning sessions at about 8 a.m. and later sessions at about 5 p.m., on average, all between 7:30 a.m. and 7 p.m.⁴ None tested training around a night shift, so this part is practical scheduling, not research. Questions about sleep and health on shift work are for a doctor; this is only about where the session goes.

• Anchor it to the shift, not the clock. "After I wake up, before I leave for work" works on days, evenings and nights alike.
• Schedule when the rota comes out. When the hours change week to week, put the sessions in as soon as you know your shifts, the way a student blocks training around a new term's classes.
• Use the floor on long stretches. On a run of long shifts, a short session or a walk still counts: the World Health Organization's guidelines say some physical activity is better than none.¹⁰

If you'd rather not plan it alone

A page can't see your rota or your class schedule. Coaching is the version where your workouts live in the Trainerize app, built around the days you actually have, and a weekly call looks at the week you just had and rebuilds the next one around what's coming. Coaching for a week that doesn't hold still explains how that works, and apply tells me about your week. Otherwise: pick a time for your next three sessions and put them in your calendar.