Training Through Pregnancy: What to Do in Each Trimester

A concrete trimester-by-trimester training plan with sets, reps and load changes, plus the warning signs that mean stop the session and call your doctor.

Pregnancy is usually not a reason to stop training, just a reason to change how you train. In an uncomplicated pregnancy most women can keep working out almost to delivery, but what makes sense changes every few weeks. Here is a practical breakdown by trimester, with numbers instead of vague advice.

The frame that applies to all three trimesters

Aim for about 150 minutes of moderate activity per week, easiest as 5 sessions of 30 minutes, plus 2 strength sessions. Judge intensity by speech: if you can talk in full sentences, the pace is right. If you need a breath every three words, back off.

Heart rate is a poor guide during pregnancy. Resting heart rate climbs by 10 to 20 beats, so use perceived effort (5 to 7 out of 10) and the talk test instead.

Never train to failure. Leave 2 to 3 reps in reserve on every set.
Breathing: exhale on the effort, no breath holding under load.
Fluids: around 500 ml two hours before, then 200 to 250 ml every 15 to 20 minutes during the session.
Heat: avoid training rooms above 28 degrees Celsius, hot yoga and saunas.
Food: first trimester calories stay the same, second trimester add roughly 340 kcal per day, third trimester about 450 kcal. Protein around 1.2 to 1.5 g per kilogram of body weight.

First trimester (weeks 1 to 13)

The limiting factor here is not the belly or balance, it is nausea and fatigue. Nothing shows yet, but energy often drops by a third.

If you were already training, keep the same program and cut total volume by 10 to 20 percent. If you are starting from zero, spend the first two or three weeks on 20 to 30 minutes of walking, 4 to 5 times a week, then add strength work.

Strength: 2 to 3 sessions per week, 5 to 6 exercises per session, 2 to 3 sets of 8 to 12 reps. A solid selection is squat, Romanian deadlift, overhead or bench press, row, split squat, and a loaded carry for 2 rounds of 30 metres. Do not chase personal records and do not introduce loads you have never handled before.

Abdominal work is still fine this trimester, but start getting used to planks and bird dogs instead of crunches, because you will be dropping crunches soon.

Second trimester (weeks 14 to 27)

Energy comes back, but the bump starts changing your mechanics. Two concrete changes:

After roughly week 16, stop doing exercises lying flat on your back for more than 2 to 3 minutes at a time. Incline the bench 15 to 30 degrees and everything continues as normal.
Drop crunches, sit-ups and lying leg raises. The risk is separation of the abdominal wall. Replace them with bird dog, 3 sets of 8 to 10 per side, side plank, 3 rounds of 20 to 30 seconds, and Pallof press, 3 sets of 10.

Strength stays at 2 to 3 sessions per week, 3 sets of 8 to 12, using a load where you could still do 3 more reps. Move deadlifts from the floor up onto blocks or a trap bar, since the bump gets in the way of the bar path.

Running is fine if you were already a runner. Cut it to 20 to 40 minutes and watch your pelvis. If you get groin or pelvic joint pain, switch to a stationary bike, elliptical or 30 minutes of swimming.

Third trimester (week 28 onward)

This phase is maintenance, not progress. Cut total volume by 20 to 40 percent compared with the second trimester.

Strength: 2 sessions per week, 2 sets of 10 to 15 reps, lighter loads, longer rest (90 to 120 seconds).
Squats: wider stance and stopping on a box or bench instead of going to full depth.
Walking: 20 to 30 minutes daily on flat ground.
Pelvic floor: 3 sets of 10 contractions held 5 seconds, plus 10 quick ones, twice a day. Learning to relax those muscles matters as much as squeezing them.
Mobility: cat-cow for 10 reps, hip openers for 2 rounds of 45 seconds per side.

If you get dizzy standing up, or contractions after a set, end the session that day without negotiating.

What to cut for the whole pregnancy

Contact and fall-risk sports: basketball, skiing, horse riding, unroped climbing.
Scuba diving.
Long sets flat on your back after week 16.
Maximal loads and breath holding under the bar.
Training above 2,500 metres of altitude if you are not already acclimatised.

When to see a doctor

Stop the session immediately and call your doctor if you get vaginal bleeding, fluid leaking, regular contractions, chest pain, shortness of breath before you have even warmed up, a bad headache that will not clear, dizziness, pain and swelling in one calf, or reduced fetal movement.

Before you start at all, clear it with your doctor if you have preeclampsia, cervical insufficiency, placenta previa after week 26, a multiple pregnancy, severe anaemia (haemoglobin under 100 g/L), or known heart or lung disease. Exercise is not automatically banned in those cases, but the plan should be written by someone who can see your results.

The short version

Target 150 minutes of moderate activity per week plus 2 strength sessions, always leaving 2 to 3 reps in reserve.
First trimester: same program, volume down 10 to 20 percent, no new personal records.
Second trimester: no lying flat after week 16 and no crunches, swap in bird dogs, side planks and Pallof presses.
Third trimester: volume down 20 to 40 percent, 2 sets of 10 to 15, plus daily walking and pelvic floor work.
Bleeding, leaking fluid, chest pain or contractions mean stop training and call your doctor the same day.