Pregnancy exercise ball: how it fits into exercise in pregnancy

What is a pregnancy exercise ball?

A pregnancy exercise ball is an ordinary exercise ball used during pregnancy. Pregnancy exercise balls turn up at home, in prenatal classes (antenatal classes in the UK) and, later on, in the room where you give birth; the object is the same in each.

Fit is the first thing to check. Cleveland Clinic (2024) describes the right size as one where you sit with both feet flat on the floor and your knees bent at about 90 degrees. That is one US hospital's rule of thumb, not a figure from a national guideline in either country, so it works best as a starting check alongside how steady you feel.

Most pregnancy exercise ball exercises are built from a few plain movements: sitting tall with your feet planted, tilting the pelvis forward and back, drawing slow circles with the hips, small bounces, and kneeling on the floor to rest your arms and chest over the ball. Many women begin by sitting on it in place of a chair for a few minutes, close to a wall or sturdy furniture, and add movement once that feels settled.

One thing sits above all of it. ACOG (2020) asks women to follow the advice of the person caring for them, in the US often an OB-GYN and in the UK usually a midwife, because that person knows things a general page cannot.

Does the evidence support exercising on a ball in pregnancy?

The evidence supports being active in pregnancy, and a pregnancy exercise ball workout is one way of doing that. ACOG's 2020 opinion on physical activity in pregnancy is the main US guideline, and its weekly recommendation is about how much you move; the choice of equipment is left open.

The reason behind it is health. ACOG links regular moderate activity in pregnancy with a lower risk of gestational diabetes and of pre-eclampsia. That is a statement of direction, lower risk, and it is tied to regular activity as a whole, not to any one piece of equipment. The fair reading is that a ball can help you be active, not that it carries a benefit of its own.

US and UK guidance broadly agree on the amount. The CDC gives healthy pregnant women the same weekly figure for moderate aerobic activity, and so does the NHS, which is helpful if you read advice from both countries.

ACOG encourages women to keep up two kinds of activity, moderate cardio and strength work. A ball session is not automatically one or the other; what places it is effort. Rocking and circling at a pace that raises your breathing sits with the cardio, and a gentler session is a pleasant addition.

ACOG also suggests steering away from contact sports and from activities with a risk of falls. A ball is not a contact sport, but the falls point speaks directly to ball work, since the surface moves under you. It is worth feeling settled and steady before adding movement, and worth keeping something solid within reach.

None of this makes the ball better or worse than a walk, a swim or a strength session. Its case is practical: it is something many women want to sit on anyway.

How much exercise in pregnancy is enough, and how often?

The weekly target is the same total in both countries; the difference is that the NHS in the UK adds 2 muscle-strengthening sessions a week to it. Neither country sets a number of minutes for the ball itself, so time on it goes into the total alongside everything else you do.

The CDC describes the total as something that can be split into 30-minute sessions on 5 days, and a ball session can be one of those five or part of one.

Moderate has a plain test. The NHS describes moderate intensity as being able to talk but not sing while you are active. If you can hold a conversation on the ball but could not manage a song, that session counts.

One adjustment comes with time. After the first trimester, the CDC suggests steering away from activities that need lying flat on the back, and the NHS puts it as not lying flat on your back for more than a few minutes in later pregnancy. For ball work, that points toward seated, kneeling or standing positions over reclining ones.

When to stop, and when to call. The NHS advises stopping if you feel uncomfortable, too hot or unwell. If that feeling does not ease once you rest, if you slip or fall from the ball, or if something feels different afterward and stays on your mind, that is a reason to call your midwife or OB-GYN the same day instead of waiting for your next appointment.

What did the studies show, and what is still unclear?

Two kinds of evidence sit behind this page, and they answer different questions. Guidelines such as ACOG's draw on research into activity in pregnancy as a whole, which is where the weekly target and the health links above come from.

Research on the ball itself is thinner. Cleveland Clinic (2024) points to a study linking ball exercises with less waist pain and fatigue and with fewer episiotomies. That is encouraging, and it is one study reported by one hospital. Neither ACOG, the CDC nor the NHS has turned it into a recommended number of minutes, repetitions or sessions on a ball.

So pregnancy exercise ball workouts that promise a precise dose are offering structure, which some women like, and not a tested prescription. You may also read that a ball can turn a baby, open the pelvis or speed up labor (labour in the UK). Those are questions about birth, which the exercise guidance on this page does not cover, so they are good ones to bring to your midwife or OB-GYN, along with anything about your pelvic floor or a pregnancy with complications.

Next steps

A good place to start is small: a few unhurried minutes sitting on the ball, noticing how it feels, and a mention of it at your next appointment with your midwife or OB-GYN. From there, you might build the ball into your active week, or keep it as an extra beside the walking, swimming or strength work you already do. If you are looking ahead to the months after birth, our guide to postpartum exercise picks up where this page stops. Some women love the ball and some never take to it, and both are fine. You are the best judge of what feels good, because exercise in pregnancy is not one size fits all.