Is There a Safe Heart Rate for Pilates in Pregnancy? An Honest Answer

No — there is no single heart-rate number that applies to every pregnant body doing Pilates, and if an app, a monitor, or an old handout told you to stay under 140 beats per minute, that rule was walked back by medical guidance decades ago. What actually matters in a Pilates class is how the work feels, not what a wrist device reports. That is a less satisfying answer than a clean number, I know, so let me walk through where the 140 figure came from, why it got dropped, and what to use instead.

Where the 140-BPM Rule Came From

The number has a real history. The American College of Obstetricians and Gynecologists (ACOG) issued its first formal exercise guidance for pregnancy in 1985, and it set a target heart rate 25 to 30 percent below non-pregnant levels, with an upper cap of 140 beats per minute. That single figure got repeated in fitness certifications, prenatal class handouts, and eventually in group exercise instructor training for years afterward, long after the guidance itself had moved on. A 2024 review of 22 international pregnancy exercise guidelines traces this exact pattern: a cap meant to be cautious in the absence of good data turned into a rule people assumed was still current.

Why ACOG Walked It Back

ACOG actually dropped the fixed heart-rate limit in 1994, and dropped it again in a later revision in 2002, because the research didn't support one number for every pregnant exerciser. Blood volume rises by roughly 40 to 50 percent over pregnancy, resting heart rate climbs on its own, and how much a given woman's heart rate rises during a workout varies a lot — some women show a blunted response to exertion, others run higher than their pre-pregnancy baseline at rest. A flat 140 cap could tell one person to stop before she's working hard enough to matter, and tell another she's fine when she's actually overdoing it. A Mayo Clinic Care Network patient FAQ puts it plainly: heart rate limits generally aren't imposed during pregnancy anymore, and the guidance instead points toward a weekly activity target — about 150 minutes of moderate aerobic activity — with no heart-rate ceiling attached to it.

That same FAQ is a good reminder that "no fixed number" doesn't mean "no check-in with your provider." It specifically flags a shorter list of situations where your clinician's sign-off matters before you keep training the way you have been: a history of preterm labor, heart disease, high blood pressure, or poorly controlled type 1 diabetes. If any of those apply to you, this is a conversation for your OB or midwife, not something to sort out from an article.

What Works Better: the Talk Test and Perceived Effort

In place of a number, the two tools that show up again and again in current guidance are the talk test and rating of perceived exertion (RPE). The talk test is exactly what it sounds like: during moderate activity you should be able to hold a conversation without running out of breath. Tommy's, the UK pregnancy charity, frames it with a second, simpler check — you shouldn't be able to comfortably sing while you're working at a moderate pace. If you can sing, you've got room to push a little harder; if you can only get out a few words between breaths, that's the signal to ease off.

RPE is the more structured version of the same idea. The Borg scale runs from 6 to 20, and the 2024 guideline review found that most current pregnancy exercise recommendations that mention RPE put moderate-intensity work at around 13 to 14 on that scale — labeled, fittingly, "somewhat hard." The same review notes that recent U.S. guidance leans on RPE over heart rate specifically because a pregnant woman's heart-rate response to a given effort is less predictable than her own sense of how hard she's working.

How This Plays Out in an Actual Pilates Class

Here's where I think Pilates has something going for it that running or a spin class doesn't: the pacing is already built in. Good prenatal-aware Pilates teaching is breath-led and controlled by design, so your heart rate rarely spikes the way it does in interval training. In practice, the talk test is easy to apply exercise by exercise — if you can still follow verbal cues and answer a question between reps, you're in a reasonable zone; if you're breathless and can't speak in full sentences during mat or standing work, that's your cue to slow the tempo or take out the arm work and keep the legs moving.

The other piece that matters more than heart rate in a Pilates room is position, not pace. Research reviewed by the Mayo Clinic FAQ above also points out that prolonged time flat on your back becomes a bigger concern than intensity as pregnancy goes on, because of how it can affect blood flow — that's a separate issue from heart-rate monitoring, and it's worth reading about on its own if you want the full picture of what changes trimester by trimester.

I'd rather a client finish a session feeling like she worked and could still hold a conversation the whole way through than watch a number on her wrist and second-guess every rep. The body is giving you better information than the monitor is.

Aviva Reinhart

Warning Signs That Mean Stop, Not Just Slow Down

None of this is a reason to push through things that don't feel right. Both Tommy's and the Mayo Clinic FAQ are consistent on the short list of signals that mean stop exercising and contact your midwife or doctor rather than simply easing off:

• Vaginal bleeding or fluid leakage during or after a session.
• Chest pain or a racing heartbeat that doesn't settle once you stop moving.
• Painful, regular contractions or tightening that doesn't ease with rest.
• Dizziness, feeling faint, or a sudden headache, especially with vision changes.
• Calf pain or swelling in one leg only, which needs medical attention rather than a stretch.
• Shortness of breath that hits before you've really started working, not the kind that builds gradually with effort.

Any one of those is worth a call, not a wait-and-see. Check with your clinician early in pregnancy about which symptoms apply to your specific situation, since a history like placenta previa or a cardiac condition can change this list.

Where to Start

If you're returning to this question after hearing the old 140-bpm rule from an instructor, a class waiver, or a well-meaning relative, you can let it go — it was retired by the same organization that created it, over twenty years ago now. Use the talk test as your everyday check during class: can you still speak? Can you not quite sing? That tells you more about your actual effort than a number that was never built for your specific pregnancy in the first place. If you wear a fitness tracker, feel free to keep glancing at it for your own curiosity, but let your breath and your provider's specific guidance — not the device — make the call on whether to ease up. And if anything on the warning-sign list above shows up, that's not a Pilates question anymore; that's a phone call.

Frequently asked

Is 140 beats per minute still the rule for exercise during pregnancy?

No. ACOG dropped that fixed heart-rate cap in 1994 and again in 2002, after research showed heart-rate response to exercise varies too much from person to person during pregnancy to use one number. Current guidance uses perceived effort and the talk test instead.

What is the talk test, and how do I use it in a Pilates class?

The talk test means you should be able to hold a conversation at a moderate pace without running out of breath; if you can comfortably sing, you can push a bit harder, and if you can't speak at all, ease off. In Pilates, check it against your breath cues — if you can't speak through them, slow the tempo.

Do I need my doctor's approval before continuing Pilates during pregnancy?

Most people who were already exercising regularly don't need special clearance just to continue. But a history of preterm labor, heart disease, high blood pressure, or poorly controlled type 1 diabetes are specific reasons to check with your provider first, according to Mayo Clinic Care Network guidance.

What symptoms during a workout mean I should stop and call my provider?

Vaginal bleeding, chest pain, regular painful contractions, dizziness or fainting, one-sided calf swelling, and shortness of breath that hits before you've really exerted yourself are all reasons to stop and call rather than simply slow down.