I always assumed I could surf all the way through pregnancy, but trying to put wetsuit boots on with a bump is near impossible! In the end, I carried on surfing until I was 22 weeks’ pregnant, but after that I had to drop the ego and stick to cold-water dips. I love photos of women who are eight months’ pregnant surfing in a bikini, but they all live in Hawaii, where the waves are much more bump-friendly. I can’t lie on my belly at this stage, so ideally you need to be able to ride a longboard where you can knee paddle, which requires mellow waves. I live in Cornwall, and in the height of winter that is just not possible!

Cold-water swimming has been more valuable than ever during my pregnancy because I just feel so weightless when I’m in the water. During pregnancy, you can lose a lot of your identity. It has been so wild to go from someone who can run 15km along a coastal path and now I can barely walk up the stairs. For me, it also meant I couldn’t carry on doing my job as a cold-water swim coach because I couldn’t fit into my wetsuit. But cold-water swimming has really been that one constant which has reminded me of who I am. It is about 10 degrees in the sea this month and the longest I have stayed in the water is around seven to eight minutes.

It has been proven that pregnant women who regularly enjoy cold water swimming can expect a better birth outcome. When you submerge yourself in cold water, your heart and breathing rates dramatically increase – this cardio-respiratory response is also known as the “cold shock” response. The breathing I teach during my cold-water swimming lessons – long, slow exhales through the mouth – is exactly the same as hypnobirthing breathing, when women use a mixture of self-hypnosis, relaxation and breathing techniques to overcome pain in labour.

Our body temperature is 37 degrees, so going for a dip in water that is 14 degrees enhances the body’s ability to adapt to stress. Last year, I was involved in research exploring the effects of cold-water swimming on depression, anxiety and post-traumatic stress disorder. I took a group of NHS workers swimming in the sea each week – some had never been in the sea in the UK before and were really quite scared. Amazingly, nearly all of them have continued swimming in the sea this winter. One woman who suffered from aches and pains said the course actually changed her life – immersing herself for 10 minutes helped her switch off mentally and even made her pain-free for a few days.