What Exercise Physiologists Actually Need to Know about Pregnancy & Exercise
Pregnancy has historically been treated as a time to reduce, avoid and modify exercise. But the conversation is changing, and the research is finally catching up.
As Exercise Physiologists, we're moving away from the idea that pregnancy requires women to become less active, and towards a model of maintaining capacity, supporting health and adapting training to the individual.
The latest Australian guidelines, released in March 2026, make this clear: for healthy pregnant women, the recommendation is to accumulate 2.5-5 hours of moderate-intensity activity OR 1.25-2.5 hours of vigorous-intensity activity per week (or an equivalent combination), alongside strengthening activities at least twice per week.
Pregnancy does not mean exercise needs to become "gentle."
Can pregnant women exercise vigorously?
Yes .. but in the right context. This is one of the biggest misconceptions we need to challenge.
The 2025 WHO maternal health recommendations state that women who habitually participated in vigorous-intensity aerobic activity before pregnancy can continue during pregnancy and postpartum, assuming there are no contraindications. The 2026 Australian guidelines go further, explicitly listing 1.25-2.5 hours of vigorous activity per week as one valid pathway to meeting the recommendations.
This doesn't mean every pregnant woman should start HIIT or CrossFit. It means vigorous intensity itself isn't automatically dangerous, context matters most. A woman running 30km a week before pregnancy is very different from a previously sedentary woman at 20 weeks wanting to start running intervals. Our job isn't to prescribe based on gestational age alone; it's to consider training history, pregnancy status, symptoms, response to exercise, goals and medical factors.
The 150-minute recommendation is not a ceiling
One of the biggest mistakes is interpreting "150 minutes of moderate activity" as a cap. That's not what the guideline says - it's a target range, and any activity is better than none. Highly active women are specifically encouraged to seek professional advice and supervision rather than scale back unnecessarily.
For competitive runners, strength athletes or recreational athletes with training loads well above population guidelines, 2026 research suggests we still don't have enough evidence to define an upper safety limit for high-volume exercise. A recent systematic review concluded the safety of exceeding current volume recommendations remains uncertain due to limited evidence. The priority is ensuring adequate hydration, fuelling and recovery.
Resistance training: stop being afraid
The 2025 systematic review by Prevett and colleagues examined resistance training - standalone or as part of a broader program - against pregnancy, delivery, fetal and pelvic-floor outcomes. The authors concluded resistance training has an important role in pregnancy and should be better integrated into exercise recommendations.
We don't need to automatically swap strength training for bodyweight squats, tiny dumbbells and endless bands simply because someone is pregnant. Instead, ask: What was she doing before? What can she tolerate now? How is she responding? What adaptations are needed? Strength training can stay progressive throughout pregnancy, even as dose and exercise selection shift.
What about heavy lifting? The 2026 guidelines advise avoiding activities requiring heavy lifting - but that shouldn't be read as "never lift heavy." A 70kg deadlift is an enormous load for one person and routine for another. The useful clinical question is what "heavy" means for this individual, in this exercise, at this stage - factoring in training history, technique, breathing strategy, symptoms, pelvic-floor and abdominal-wall response, fatigue, gestational age, complications and overall volume.
The pelvic floor conversation needs to change too
Pelvic-floor messaging in pregnancy is often reduced to "do your Kegels." But it's more nuanced - encompassing contraction, relaxation, coordination with breathing, pressure management, impact tolerance, and symptoms during and after loading.
The 2026 guidelines recommend pelvic-floor exercises during pregnancy and beyond. If a woman develops leakage, heaviness, pressure or pain during exercise, that's not necessarily a sign to stop forever - it's a sign the load needs reassessing. That might mean adjusting volume, impact, exercise selection or intensity, and potentially referring to a pelvic-health physio.
What does vigorous exercise actually look like?
The guidelines use the talk test: at moderate intensity, conversation is manageable; at vigorous intensity, it becomes difficult. As EPs we can also draw on RPE, symptoms, performance and recovery. Heart rate can help, but pregnancy's physiological changes make fixed HR thresholds unreliable as a standalone tool.
Importantly, vigorous doesn't mean maximal. Evidence remains limited around very high intensities, particularly above ~90% of max heart rate. A 2026 review of elite and sub-elite athletes found no consistent evidence of adverse outcomes from high training loads, but flagged that the evidence is limited, heterogeneous, and especially uncertain above that threshold. So: vigorous ≠ maximal, and vigorous ≠ automatically unsafe.
What should we actually modify?
Rather than arbitrary restrictions, think in terms of responding to changing physiology:
Position - supine, prone and prolonged static positions may need adjusting based on gestational age, symptoms and tolerance.
Impact - running and jumping aren't automatically off-limits, but tolerance should be monitored.
Balance - a shifting centre of mass raises fall risk, so exercises and environments may need reconsidering.
Range of motion - changes in body shape and mobility may make previously comfortable ranges inappropriate.
Load - may need to shift with symptoms, fatigue, technique and goals.
Volume - recovery capacity can fluctuate significantly across pregnancy.
Environment - heat and hydration become increasingly important.
The guidelines specifically recommend avoiding activities with significant fall or collision risk, pressure changes, or anything causing pain or discomfort.
The red flags
This is where EP scope and clinical reasoning matter most. Exercise should stop, and medical assessment be sought, if a woman experiences: vaginal bleeding, dizziness or faintness, chest pain, unexplained shortness of breath, significant weakness, calf pain or swelling, regular painful contractions, fluid leakage, or significant pain. ACOG identifies the same warning signs. Women with pregnancy complications need individualised medical advice before continuing or starting exercise.
The 2026 takeaway for EPs
The biggest change we need isn't in our programs - it's in our language.
Instead of "let's make everything light," try "let's work out what your body can tolerate and maintain your strength and fitness safely." Instead of "don't get your heart rate too high," try "let's monitor intensity using symptoms, RPE, talk test and individual response." Instead of "no heavy lifting," try "let's assess your lifting history, technique, symptoms and overall pregnancy status." And instead of "stop running," ask: "how is running feeling, and how does your body respond?"
Pregnancy is not a reason to stop training. It's a reason to train differently when necessary. Our goal isn't to make pregnancy exercise "safe" by stripping out every challenging stimulus - it's to understand risk, recognise contraindications, monitor the individual, and preserve as much strength, fitness, confidence and function as possible. In 2026, that can absolutely include vigorous exercise for appropriately screened women with healthy, uncomplicated pregnancies.
