"I’m Pregnant… Now What?" Your Guide to Training in the First Trimester of Pregnancy

December 31, 2025•4 min read

Finding out you’re pregnant can feel both magical and completely overwhelming.

For many women, one of the very first questions is:
“Can I still exercise?”

Closely followed by:

“Am I going to hurt the baby?”
“Should I stop lifting now?”
“Is it safer to just rest?”

If this is you, you’re not alone and you’re not wrong for wondering. You care deeply about your body and growing baby.

But let’s walk through what the current evidence actually says about training in the first trimester so you can shift from feeling fearful to feeling confident.

The Reassuring Truth About Early Pregnancy & Exercise

For most women with uncomplicated pregnancies, continuing to exercise in the first trimester is not only safe — it’s encouraged.

Guidelines from organisations such as the ACOG (American College of Obstetricians and Gynecologists ) and Exercise and Sport Science Australia support regular physical activity throughout pregnancy, including strength training.

In simple terms:

If you were exercising before pregnancy, you can usually continue doing what you’re doing — with awareness and flexibility.
If you were not exercising before pregnancy, you can usually begin exercising and gradually build up — again, with awareness and flexibility.

Pregnancy doesn’t require you to stop moving or drastically change what you were already doing. It simply asks you to listen more closely.

What’s Actually Happening in Your Body (Why You Feel So Tired)

Before diving deeper into training, it’s important to acknowledge what your body is doing in those first days, weeks, and months.

The first trimester is one of the most physiologically demanding phases of pregnancy. Even if you don’t look pregnant yet, your body is working incredibly hard.

❤️ Cardiovascular Changes

Blood volume begins increasing early
Resting heart rate rises
Your body works harder to deliver oxygen and nutrients to your baby

➡️ What this means: You may fatigue faster — even during everyday tasks. This is normal.

🫁 Oxygen & Breathing

Oxygen demand increases
Breathlessness can occur sooner during exercise

➡️ This doesn’t mean exercise is unsafe. It means your body is adapting to increased demand.

🧠 Hormones & Fatigue

Several hormones rise rapidly in the first trimester, including:

Progesterone (major driver of fatigue and sleepiness)
hCG (often linked to nausea)
Oestrogen (affects mood, circulation, and energy)

➡️ Fatigue, nausea, and emotional shifts are extremely common.
➡️ Some days will feel great. Others won’t. Both are expected.

Should You Rest More in the First Trimester?

Yes — rest is important. Your body is expending a huge amount of energy laying the foundations for your growing baby.

But resting all the time often isn’t helpful either.

Even when you feel exhausted, gentle, consistent movement can:

Improve energy levels
Support mental health
Reduce nausea for some women
Maintain strength and confidence

Often the sweet spot looks like:
Shorter sessions. Reduced volume. Same movements.

Many women are surprised to find that moving their body — even briefly — actually helps them feel better, not worse.

Strength Training in the First Trimester

Strength training is not dangerous in early pregnancy.

In fact, continuing to lift weights can:

Maintain muscle mass
Support posture and joints
Build resilience for later pregnancy and motherhood

There are NO blanket exercises you “must” stop purely because you’re in the first trimester.

What matters most is:

How you feel during and after sessions
Managing fatigue
Adjusting load and volume as needed

A Simple Framework for First Trimester Training

Instead of rigid rules, use these principles:

✔ Train at a comfortable intensity
✔ Leave 3-4 reps in reserve
✔ Scale volume back before eliminating any movements
✔ Prioritise consistency over perfection

Also know: you are not fragile — your body is simply adapting.

It won't always feel this way.

The fatigue and nausea of the first trimester can feel incredibly overwhelming — especially if this is your first pregnancy.

Every woman’s journey is different, but the good news is that many women begin to feel more like themselves again around the 14–16 week mark, as hormones such as progesterone and hCG start to stabilise.

If you can gently hang in there and keep yourself moving during this phase — even though it may require more mental discipline than physical effort — it often feels much easier once your body adapts and your energy begins to return.

You got this mama!!!