Gwen Jorgensen, Liz Blatchford and Nicola Spirig, to name but three top female pros/mums, have all shown motherhood shouldn’t be to the detriment of performance, and the science reveals that there are physiological benefits.
One structural adaptation is the expansion of the ribcage during pregnancy, which would assist breathing, but of even greater benefit are the cardiovascular changes. Both age-groupers and elites enjoy up to a 50% increase in blood volume during pregnancy and up to an 18% increase in red-blood cell count. Stroke volume – the amount of blood pumped out on every beat – also rises by 10%. All these adaptations are heavily down to supplying the foetus with oxygen, which is also nectar for endurance athletes.
What’s key is that the body doesn’t revert to normal once the baby’s born for anything up to 12 months. This is highly individual and includes factors like diet, ease (or not) of birth and training regime, but theoretically means there’s a favourable window for endurance athletes.
It’s also been noted that women’s oestrogen levels are higher during pregnancy – oestrogen stimulates the release of the hormone serotonin that essentially makes exercise feel less painful and so minimises fatigue.
Then there’s the psychological factor of dealing with unique levels of pain that, whether consciously or sub-consciously, you can take into subsequent training sessions. The result? You dig deeper. Again, this is clearly a difficult one to quantify and highly individual but does point to improved performance.