Safe training in pregnancy: what changes and what to adjust
For the large majority of healthy pregnant women, exercise is recommended rather than merely allowed. The question is almost never whether you may train, but what to adjust and when. This tool gives you a framework based on your trimester and situation, and the final word always belongs to the doctor following your pregnancy.
What changes in your body
Three changes affect how you train. Joints become more mobile because of hormonal changes, so it is easier to overshoot a range of motion. Your centre of gravity moves forward as your bump grows, which changes balance and loads the lower back. Blood volume and breathing rate increase, so you get out of breath sooner at the same effort. None of these is a reason to stop, but all three are reasons to adjust.
Adjustments by trimester
In the first trimester the biggest limiting factor is nausea and fatigue, so doing less and shorter is normal. In the second trimester energy usually returns and it is the best period for consistency, with the first positional adjustments. In the third trimester balance decreases and pelvic pressure increases, so you move to more stable positions, shorter sets, and more walking, swimming or guided strength work with lighter loads.
What is avoided
Avoid activities with a risk of falling or impact to the abdomen, such as skiing, horse riding, martial arts and contact team sports. Scuba diving is not recommended in any trimester. Also avoid exercising in hot and humid conditions, hot yoga and saunas, because overheating in early pregnancy carries risk. Maximal lifts with breath holding are not appropriate, while moderate strength training is encouraged.
The question of lying on your back
The standard recommendation is to avoid prolonged lying on your back after roughly sixteen weeks, because the uterus can compress a major vein and reduce blood return. In practice how you feel matters more than the exact week. If you become nauseous, dizzy or short of breath in that position, roll onto your side. Short exercises on your back are often fine, and the alternative is to do them inclined or side lying.
If you did not exercise before
Pregnancy is not the time to suddenly start intense training, but it is a good time to start moderate activity. Walking, swimming, a stationary bike and a guided strength programme with lighter loads are safe for most healthy pregnant women. Start with ten to fifteen minutes and add a few minutes per week. Most of the benefit comes from consistency rather than from how hard the sessions are.
When to stop immediately
Stop and contact your doctor if you have bleeding, fluid leaking, regular painful contractions, chest pain, a severe headache, dizziness, shortness of breath before exertion, calf pain or swelling, or if you notice reduced fetal movement. These signs take priority over any plan and are not something to push through to the end of a session.
How a kinesiologist helps
A kinesiologist experienced in prenatal work does not hand you a list of banned exercises but a programme that changes with you. They track how you feel week to week, swap exercises that have become uncomfortable before they become a problem, and keep the pelvic floor and abdominal wall in view throughout the pregnancy, which shortens recovery after birth.
Written by Ozana Brkić, MSc in Kinesiology, a certified kinesiologist specialising in prenatal and postnatal training. Content last reviewed: August 2026.