Is it OK to work out on your period?

In general, yes, lifting weights included. The American College of Obstetricians and Gynecologists (ACOG) and the UK's National Health Service (NHS) both suggest exercise as a way to ease period pain, and a 2020 review of 78 studies found that exercise performance on your period drops very little, if at all. Tiredness and cramps are common, so plan each session around how you feel that day, not your cycle phase.

By the STRONG team · Updated October 2026

Lifting weights on your period: are you weaker?

That 2020 review (McNulty et al., 1,193 women in total) found that exercise performance on the days you're bleeding "might be trivially reduced" compared with the rest of the cycle. The margin of error is wide enough that there may be no difference at all. The evidence was low quality, and the authors concluded that no general guidelines on performance across the cycle can be formed. They recommend a personalized approach instead. If you've read that you should only lift heavy in certain weeks, our guide to cycle syncing and strength training goes through the studies behind that idea.

Why workouts can feel harder around your period

In a survey of 6,812 women who exercise (recruited through Strava, none on combined hormonal birth control), mood changes, tiredness and cramps topped the list.

Women with more symptoms had higher odds of missing or changing a workout. The answers are self-reported, and several of the authors work for a company that makes a cycle-tracking app. If your energy usually dips in the days before bleeding starts, our guide to working out when you're tired before your period covers that stretch.

How to work out on your period

Say it's day one, your lower back aches and your warm-up sets already feel heavier than last week. You can keep the same exercises and shrink the session: do fewer sets, stop a rep or two earlier, and on your worst days take a little weight off the bar.

RPE is a 1 to 10 effort scale, where 10 means you couldn't have done another rep. On a lighter day you keep the same weight and do one set fewer, each a little further from failure. On a very light day you also drop to about 90% of the weight, and at RPE 6 you finish each set with several reps left in the tank. Neither kind of day can raise your weight, so the next increase waits for a normal session. Progressive overload for women covers when and how much weight to add.

Best workouts during your period

The NHS suggests "gentle exercise like yoga, swimming, walking or cycling." A Cochrane review of 12 trials with 854 women found low-quality evidence that exercise may lower period-pain intensity by about 25 points on a 0 to 100 scale. None of the trials in that review tested lifting. They used stretching, core work, yoga, Zumba and aerobic training, and some even asked women not to exercise during their period. So none of those trials compared a light lifting session with a walk on a day with cramps. Our take: a lighter version of the lifts you already do is a fine choice on those days, and so is a swim.

How STRONG plans lighter days around your period

If you opt in, STRONG asks how much your energy drops (hardly, noticeably or a lot), when it drops (the days before bleeding, the first days of your period, or both), and whether the dip lasts longer than a week.

1. If your energy drops noticeably, you get 2 lighter days. If it drops a lot, you get 3 very light days. A dip that lasts longer than a week turns that into 5 lighter days or 7 very light days. If you answered "both", you get that many days before your period and again in its first days, with no more than 10 in a row.
2. Lighter and very light days are set up the way the squat table above shows.
3. The planner also marks one day on either side as a lighter day, because periods drift by a day or two.
4. If you'd rather, your hardest days can be planned as upper-body only (lower-body sessions move to other days) or as rest days (the week is planned around them).
5. If your energy drops noticeably or a lot, an easy week (the app's name for a deload week) is placed around every predicted period, where you choose: the week before your period, the week it starts, or half of each. With fewer than 2 loading weeks since your last break, it's a lighter week instead (one set fewer, same weights), and two breaks never come back to back. If your energy hardly drops, you get no lighter days, but a deload that's due moves onto your period week.

With irregular cycles, tap "My period started today" when it does and the next days are planned lighter. STRONG makes no prediction until you've logged at least 2 cycles that differ by 10 days or less. From then on it uses the median of your last 3 cycle lengths (or fewer, if you've logged fewer) and widens the buffer by up to 3 days as your cycles vary more. Your cycle data, meaning your last period start, cycle length and energy answers, stays on your phone and is never uploaded. You can change any answer in Settings, and your plan and reminders update at once, or delete your cycle data there.

When to see a doctor

Get medical help right away if your period pain is severe or worse than usual and pain relievers haven't helped. Make an appointment if your periods get more painful, heavier or irregular, if you're bleeding between periods, if period pain keeps you from your usual daily activities, or if you've missed 3 periods in a row. For heavy periods, the NHS gives concrete signs: changing a pad or tampon every 1 to 2 hours, periods that last longer than 7 days, and clots larger than about 2.5 cm (1 inch). Skipping exercise because your bleeding is too heavy is on that list too. Mention it to your doctor.