How to adapt your fitness programme for the first trimester of pregnancy


Stuck on how to exercise now that you’re pregnant but still in that limbo land where you’re not ready to tell anyone? 

Here’s my step-by-step guide to exercising safely during your first trimester, that doesn’t involve getting to a new class or telling too many people about your change in circumstances.


According to Public Health England and the Royal College of Obstetricians and Gynaecologists  it is safe to continue with your regular exercise during the first trimester. The main difference now will be a change in your training goals. Pregnancy is all about maintaining your fitness and strength, managing your energy levels (you’re growing a person) and replenishing after exercise. In short, you’re now in maintenance mode. You’re trying to minimise de-conditioning and stay fit for what will be an endurance event ahead. 

The only exceptions to this will be if you’re under the care of a consultant for specific fertility treatments or interventions such as embryo implantation or if you have any of the ‘red flag’ issues I’ve shared below.* If you’re reading this, then you’ve probably already had those conversations and will be totally clued up on dos and don’ts. If you’re not sure, do ask your consultant, GP or midwife if it’s safe for you to exercise. They know your medical and pregnancy history, I don’t!


Now is the time to skip the high intensity intervals for steady state exercise. With blood volume, hormones and energy levels all over the place, interval training probably won’t feel great and you don’t need it. Remember you’re not aiming for fitness gains at the moment, you’re aiming for maintenance and managing energy levels. 

During pregnancy you’ll have a lower ratio of red blood cells to plasma than normal, leaving you slightly anaemic (some women experience more severe anaemia during pregnancy) so you don’t want to challenge your oxygen levels further by over-doing your cardio. Over exercise will also make you feel knackered!

If you love your regular HIIT class or circuits you can still go, just ease of the intensity, take a lower impact option and take more active recovery between each set. Think about peaking whilst you can still hold a conversation rather than working out until you’re fit to burst. Let’s call it moderate intensity intervals! 


Whilst this may be an alien concept to the super over achieving, busy, organised mum-to-be, if you don’t rest it’ll come and find you. That fatigue? It’s not going away any time soon. The only way to overcome it is to give in and rest. You are growing a person. That takes A LOT of energy (on average 62,100 per pregnancy).

If you’re used to exercising to give you energy, times have now changed and it can be REALLY frustrating. Think about your exercise like snacking. Little and often to boost your energy levels and get your essentials in but easy to recover from. Switch the 60 minute class for a 20-30 minute burst and make sure you recover between sessions. I’ve included a suggested weekly diary below.


Squat, lunge, hinge (deadlift), row, push, shoulders and core. Now is the time to get back to training basics. You don’t need fancy gimmicks or equipment and you certainly won’t be flipping tyres for a while. When you want to maintain strength and fitness a decent, basic strength and conditioning programme is ideal. And yes – now is the perfect time to really get to grips with your pelvic floor exercises too.

If you’re new to these exercises, find a trainer who can coach you through the movement patterns and technique and build up slowly (get in touch if you’d like some help with this). Always start with movement before loading an exercise. 

Getting stronger not only prepares your body for the challenge it’s about to undertake – carrying around extra weight for 9 months – it helps future proof your body and will help with post natal recovery. Most women I see after birth are very de-conditioned, the more you can avoid muscle atrophy and de-conditioning, the quicker your recovery will be.


There are more blood vessels, different hormones, a growing person, fatigue and a lower ratio of red blood cells (the oxygenators) to blood throughout pregnancy. That’s the summary anyway – it all fluctuates throughout pregnancy. In the first trimester it’s like – BOOM! From not pregnant to SWITCH ON THOSE HORMONES. Dizziness, fatigue, joint laxity and nausea, all those early days feels will hit you like a ton of bricks if you head straight into your regular workout without a warm up. 

Take a little more time to warm up (5-10 minutes) and cool down after a session. Some basic mobility or a walk in the fresh air will get your body and your mind ready for exercise, it’s also great practice for strength and conditioning since you can mobilise your joints and prepare your body for the movements with lighter weights.


Women often ask me if they can do x class, y activity or z training programme. The short answer is: probably. And it will probably do you no harm. Guidelines consistently state you can train as you did before in the first trimester BUT I always caveat any exercise choice with: ‘Will you feel safe and confident doing it?’ 

Most of us who exercise regularly, do so and sustain it because it makes us feel good. If exercise is a chore to you then it’s highly unlikely you’re reading this because you’ll happily take that first trimester option of doing nothing at all. If you exercise to feel good and doing your regular class sows a little seed of doubt that it might not be the best thing for you right now, then don’t do it. And that might mean making a few excuses to not join friends for a regular kickboxing session for a few weeks. That’s okay (you can explain later). 


During pregnancy, hormones conspire to create laxity in your blood vessels, ligaments and just about everywhere! Ligaments are bands of tough elastic tissue around your joints. They connect bone to bone. Stretching them can make your joints more unstable. Like knicker elastic, they have limits! Over stretch them for too long and they stay floppy and will offer less support. This is why it’s important to focus on stability during pregnancy as a way of maintaining joint stability now but also for the rest of your life. It’s a future-proofing thing. It’s also the reason why just because you CAN do something – and social media loves to show us pregnant women doing all the fancy yoga poses – doesn’t mean you SHOULD. 

I’d always encourage women to stick to two feet on the floor when training (squats rather than single leg work) and avoid exercise that may increase instability. Joint stability is another really good reason to follow a regular strength and conditioning programme (at least twice a week).

Want to learn more about adapting your exercise programme during pregnancy? I’ve got the perfect Pilates during the first trimester class available to download. It’s still your favourite Pilates moves with core strength, pelvic floor and conditioning moves thrown in, adapted for the first trimester and easy to fit in to your busy schedule. 

Need more detail?

You can get more detail on what, when and why to exercise during the first trimester here: Exercise in the 1st Trimester

Get in touch to find out more. 

*For a full list of contraindications to exercise during pregnancy click here: British Medical Journal

For details on Karen’s ante natal classes visit: Pilates for Pregnancy

More articles like this? Check out:

Can I run when I’m pregnant?

Why do we get fat when we get pregnant?

Help! I’m really pregnant. Why do I need to pee every time I stand up?

Help! I’m getting pregnancy leg cramps. What can I do?

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  1. So important to keep doing some activity while you’re pregnant. And pilates surely helps with the lower back pain

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