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Cycling while pregnant: Is it safe and what are the risks?

‘It doesn’t matter whether you don’t ride for nine months, or you ride to the maternity ward, your bike will be there afterwards’

Robyn Davidson
21 Dec 2021

Ultimately a lot of decisions you can make while pregnant are a matter of personal choice. It can be down to your own beliefs, as pregnancy differs for everyone.

From safety while cycling to the benefits of doing so and tips to make it easier, hear from Olympians to authors and doctors on their experiences of cycling while pregnant and advice for others.

Is it safe to cycle while pregnant?

In short, yes! In terms of health for yourself and the baby, it is safe to cycle while pregnant.

Dr Lou Atkinson, a psychology lecturer who holds a PhD in Health Psychology and has been conducting research into physical activity before, during and after pregnancy since 2008, explained the benefits of the low impact nature of cycling and having body weight supported by the saddle.

The hormone relaxin is released in the early stages of pregnancy. Body weight increases and joints become less stable as blood vessels and connective tissues are softened to support the growing foetus. 

In the first trimester, this can cause vascular underfill. The size of blood vessels has increased yet blood volume hasn’t kept up. 

Nausea, dizziness, breathless and fatigue are symptoms that can manifest as a result. Dr Atkinson, additionally a Level 3 certified Personal Trainer and Pre- & Post-Natal Exercise Instructor, notes that it’s important to not put pressure on yourself to train at a pre-pregnancy level if this occurs. 

She wanted to reassure women that this will pass as they reach their second trimester.

As Relaxin can cause joints to be less stable, climbing steep inclines or using a high gear can cause discomfort or inflammation. 

If this happens, rest until the pain disappears then modify your intensity in future sessions to avoid overloading the joints. 

Cycling is ideal for those just getting started with exercise, or as an alternative to more high impact activities such as running or boot camps.

One thing that should be highlighted early is that core temperatures above 38 degrees can be dangerous for the foetus – especially in the first trimester. 

Dr Atkinson said; ‘Although it is fine to feel warm and turn pink when being active, women should avoid conditions which could lead to becoming overheated, ie, cycling outdoors in hot weather, or indoors in a heated or poorly ventilated room.

‘Wearing appropriate clothing and staying hydrated is also important for staying cool.’

Elinor Barker, who was pregnant while winning silver in the team pursuit at the Tokyo Olympics, wanted to highlight the importance of distinguishing cycling for performance versus cycling for leisure.

‘I am still training for performance. It’s not so much just like exercise to keep fit. I’m not really getting any PBs or anything, but I still have targets post pregnancy that I’m training towards.

‘That’s what my coaches and I have in mind. As much as it has to be led by me and how I’m feeling and what I’m capable of day to day, it’s still very much a performance training programme. It is possible to have that kind of dual lifestyle, I suppose.’

Of course other concerns that might have been minimal pre-pregnancy can become a larger risk, such as falling off while struggling to unclip – a common experience – and navigating winter conditions like ice and snow.

‘What I’m a bit more cautious with is the smaller falls that would maybe be embarrassing six months ago, but that now could actually be a bit of a nightmare. With things like going out in the snow, or going out on the ice, I’d rather just ride hard on the turbo than go out and be riding really slowly and really cautiously.’

This is something Dr Atkinson discusses too. It is important to avoid abdominal trauma such as falling onto or having something collide with the bump. 

‘For this reason, some women might prefer to stick to cycle paths than roads, and avoid some forms of off road cycling such as downhill mountain biking, BMX or cyclocross.’

Hannah Reynolds, author of 1001 Cycling Tips, agreed that cycling while pregnant is a personal decision. Whether you’re cycling indoors on the turbo or outdoors on the road, you know your own capabilities and are aware of the risks.

‘I chose to cycle outside. This is a very personal decision for people. I know women who chose to cycle indoors because they were worried about what would happen if they were involved in an accident. I don’t mean just other road users, like literally just not unclipping their feet and falling sideways.

‘When you’re pregnant, even though you don’t have a physical baby in your arms, you start thinking like a mother and start making decisions for that unborn person. Am I still protecting them if I go out cycling on the road?

‘For me, I’ve ridden a bike for many, many years, I’m in a safe area, I’m very confident about my skills. It keeps me fit and healthy both mentally and physically. So yes, I’m going to carry on cycling outside, and that’s my choice. Other people don’t.’

What are the benefits to cycling while pregnant?

Image: Jonny Hunter, licensed under Creative Commons

Gareth Cole, co-founder and head of performance at Coach London, cited benefits as being psychological and physical, with the low-impact nature of cycling also being a positive.

‘Cycling is often the preferred prescribed exercise whilst pregnant because it is an aerobic activity, but it is also non-weight-bearing and low impact.

‘Listening to your body is certainly different during pregnancy, as mood and energy can change from day to day or even hour to hour.

‘Exercise has been shown to improve a myriad of symptoms and promote general fitness during pregnancy. From a physical perspective, a sustainable exercise routine can reduce lower back pain and unwanted inflammation whilst also promoting muscle tone and aiding in weight management.

‘It can help you psychologically by boosting mood and energy levels, which then help optimise and stabilise your sleep patterns.’

One benefit of cycling through her pregnancy for Reynolds was that due to the changing nature of her life, cycling was her way of still feeling like herself. Despite not riding to be competitive, Reynolds still cycles to stay healthy.

‘Towards the end, I think my reasons for riding changed. It became less about fitness and more about getting outside and feeling like myself, as my world was about to change.

‘Mentally it’s really good that it takes nine months, because it took me nine months to get my head around the fact I was going to have a baby. I think with cycling as well, you've got to have those periods of like, why am I cycling?

‘I’m not cycling to be fast and to be competitive and to win my next race. I’m cycling to stay fit, stay healthy, to enjoy the outdoors, to get some fresh air, to stay feeling like myself as everything else is changing.’

Do I need to adjust my bike while pregnant?

Image: Lisa Larsson, licensed under Creative Commons

From switching to a shorter stem or a different saddle, or even changing to a mountain bike or an e-bike, there’s no shortage of adjustments you can make for a more accommodating ride while pregnant.

Reynolds says, ‘Bike setup is really important, and that changes as you go through. When I was first pregnant, you get hormonal changes that affect your joints and ligaments almost straight away. Even though there was like no bump to accommodate, I already needed to change my riding position to be a little bit more upright and relaxed and not be leaning forwards.

‘Mentally, it also made me feel a little bit different, because I used to be a really fearless descender on the road. Then yeah, maybe I’m not going to go down on the drops and I’m not going to do it quite as fast as I normally would. Changing my bike position also changed my mindset that I did ride a little bit differently.

‘Then as you go on, you obviously need to physically accommodate a bump. Most people on road bikes find they need to shorten their stem, raise their handlebars, maybe switch from their road bike to a mountain bike or a hybrid.

‘You might find that your saddle comfort differs because there’s changes to your soft tissues and ligaments around your pelvis. If you’re used to sitting on a racing saddle, something quite narrow and quite hard, you might want to change your saddle quite quickly.’

Barker said, ‘I've started going up a stack on my forks. I think I've only actually got one spacer left. I'm also going to borrow a mountain bike, which I think would be nice just to be really upright because it's not as linear as I expected it to be.

‘I have days where it feels like the bump is really, really in the way. Just to be able to have the option of being sat upright will be quite nice.’

Dr Atkinson added that aero positions will be difficult to maintain as the bump grows. Balance and stability can also be affected.

‘Handlebars can be raised, and/or the seat lowered to have a more upright position. Lowering the seat also makes it easier to put your feet down when stopping.’

Victoria George, wife of Avaris eBikes founder Richard Heys, used the brand’s 2.3 Road e-bike during pregnancy as the more pregnant she became, the more help she needed.

‘It allows me to control the amount of work I need to do, as on some days I’ve been able to manage more exercise than on others, depending on the amount of energy I have and how much discomfort I’m feeling.

‘It’s been good because other than walking and jogging, which I did during the earlier months of my pregnancy, other forms of exercise requiring more power have been difficult for me to do.’

Another adjustment can be through cycling clothing. As pregnancy can affect different parts of your body, some might find their bib shorts can be used for the entire nine months, whereas others, like Reynolds, use men’s bib shorts.

‘I actually found men’s bib shorts were the best because they came up over the top of the bump unlike some of the women’s shorts, they would be cutting in underneath it.’

George has found that maternity cycling shorts and oversized T-shirts work for her.

What food do I need to take cycling while pregnant?

You don’t quite need to eat for two straight away, but taking on extra food and water while pregnant can be an issue for those experiencing nausea.

‘It’s been quite mixed,’ Barker says, ‘because I think the days that I felt quite sick, it was really hard to take enough on board. If I wanted to eat a bar, I’d have to stop for 10-15 minutes and wait for it to go down because if I kept riding, I would just feel really sick. I probably wasn’t drinking as much water as I needed to either.

‘In terms of actual calorie intake, it’s nowhere near as much more as you think it’s going to be on paper, but it feels like quite a lot when you’re actually doing it.’

In the book Roar that Barker discusses further below, nutrition scientist and exercise physiologist Stacy Sims agrees that it takes fewer calories to ‘eat for two’ than people believe. In the first trimester, it’s about 100 more calories per day than consumed pre-pregnancy, which increases to 300 calories for the following two trimesters.

Sims places an emphasis on not eating and training like a man – as this is what research has previously dictated. This is something that Esther Goldsmith, sports scientist at Orreco, agreed with.

‘Historically, females have been trained like males, because a lot of the sports science research and the research that lots of protocols are based on has just been done on men,’ Goldsmith says.

‘We need to appreciate that men and women have different bodies, and therefore have different physiologies. That might mean then we need to have different considerations around everything that encompasses being a female.’

Sims also notes you will need to increase your intake of essential nutrients such as calcium, iron and folate while pregnant. A balanced diet containing fruits and vegetables with whole grains and proteins should suffice.

Tips for cycling while pregnant

Elinor Barker: Talk to those around you

‘I’ve been getting as much information from as many people as I can really. I’ve been speaking to riders and Lizzie Deignan sent me a message that was really informative and useful. I’ve also spoken a bit to Nikki Brammeier. It’s just so nice how supportive people are.

‘I’ve spoken to every physiologist that I can who has any kind of knowledge about it too. Before I was ready to tell anybody I was reading Stacey Sims’ book called Roar, which was actually a present from Katie Archibald.

‘I don’t think she had any idea how useful it was going to be because there is a whole chapter on training through pregnancy, which I just found a lot more specific than just Googling. Google is very broad. So that was kind of my bible to begin with, telling me what I should and shouldn’t expect and what was and wasn’t safe.’

Victoria George: Take breaks while riding, purchase an e-bike if you desire

‘I would say pregnant women wanting to keep up with cycling during their pregnancies need to listen to their own bodies. It’s possible to do, even on a traditional bike, but adjusting your routes, the amount of time you cycle for and how often you do it, is key.

‘Everyone experiences different kinds of pregnancies, and some may find cycling easier than others. I’d recommend cycling with someone if you can – a partner, friend or relative – and take breaks if you need to. We’ve mainly been going on rides at places where there are seating areas and cafes, to give my body a little bit of a break on the longer rides.

‘For women who want to cycle but are finding it too uncomfortable or difficult on their traditional bikes, I’d also recommend hiring or purchasing an e-bike, because it makes riding so much easier and more enjoyable when you're carrying a baby around, but you can still allow yourself to exercise too.’

Gareth Cole: Avoid increasing your core temperature

‘One thing to keep in mind in the first trimester is overheating. Ensure to choose the right environment and clothing to avoid increasing your core temperature.

‘Additionally stay hydrated throughout those earlier training sessions and through your recovery.’

Dr Lou Atkinson: Safety equipment is key, pick a circular route to ride

'Safety equipment is a must! If you’re new to cycling, make sure you wear a helmet, reflective clothing and have working lights on your bike. Get your bike serviced regularly to avoid mechanical issues.

'If you feel unwell, dizzy or very tired, listen to your body and slow down or take a break. Push your bike and walk if needed. 

'Picking a circular route can be a good idea, so you are never too far from home if you need to end your ride early.

'Women who were cycling before pregnancy can continue with the same duration and intensity if they feel comfortable to do so. Many women find it comfortable to stay at a moderate intensity once pregnant (slightly breathless but able to hold a conversation) and this is safe for all healthy pregnant women.

'Those who have not been regular cyclists are safe to start cycling, beginning with short rides of 15 minutes and gradually building up duration and intensity. Women can keep cycling as long as they can fit the bike and it feels comfortable.’

Look at perceived exertion rather than heart rate when guiding training intensity.

'Another change to be aware of includes an elevated heart rate, as the body needs to circulate more blood to supply both mum and baby. 

'This can mean that heart rate is less useful for guiding intensity of training, and women should primarily work with perceived exertion.’

Be mindful of altitude 

'Due to the lower oxygen levels at altitude, this can risk insufficient oxygen for both mum and baby in women who are not fully acclimatised.’

Hannah Reynolds: Rely on your own instincts, avoid hot conditions

‘Most midwife advice and doctor’s advice is to keep doing what you’re used to doing. There's some advice around temperature, because you don't want to elevate your core temperature and raise the temperature of the baby because that is known to be a risk factor.

‘You’re told to avoid hot baths and things that are going to raise your body temperature, like cycling in really hot conditions. But other than that, generally the advice is to just do what you feel comfortable with and rely on your own instincts to make good choices.

‘That can be really difficult because obviously, what an elite athlete is comfortable with, and used to doing, is quite extreme. So it can take a lot of self awareness and decision making. That can be really hard because when you’re pregnant, you can become quite... not anxious, but you want to do the right thing. So not having any set guidelines can make that quite hard.

‘But by and large, people who exercise are quite body aware, so they’re quite sensitive to things feeling good and feeling bad, and then having to make decisions.’

Whatever you choose is right

‘When it comes to cycling, whatever you choose is right. I wrote in the book, there’s a lady I know who cycled to the doctor’s to get a sweep when she was overdue. There was someone else I know who had a positive pregnancy test and was like that’s it, I’m not riding my bike outside.

‘You’ve got to do it your own way. It doesn't matter whether you don’t ride for nine months, or you ride to the maternity ward, your bike will be there afterwards. Your relationship with it might have changed, but it will still be there and it will be ready and it will be waiting for you.

‘And you can resume your cycling pretty quickly, depending on obviously how the birth goes and how the early days of having a baby goes. But you can get back on your bike really fast.

‘So don't don’t let that kind of need to be cycling fit detract from your enjoyment of your pregnancy, because it will be there at the end, however you choose to cycle through.’

Main image: Richard Masoner, licensed under Creative Commons

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