Serena Williams may have been pregnant when she won the Australian Open, so the New Scientist asked whether her pregnancy may have helped—as if her previous 38 major titles were flukes. But this is a myth that’s been floating around for a while, so let’s talk about what pregnancy really does to an athlete’s body.
A woman’s body produces more blood during pregnancy. A similar change happens to athletes as they train. With more blood, you can supply more oxygen to your muscles. Does that mean pregnancy provides a performance boost?
Too bad there’s no evidence to support that idea. Pregnant athletes’ experiences tend to go the opposite way. I got pregnant while I was training for a marathon, and I found that even though I kept up my training, my fitness went down the toilet. Usually you get faster as you train; I was getting slower. My long run pace slowed down from 10:30 per mile to 12 minutes, and I was consistently the last one to finish group training runs. At five months pregnant, I considered myself lucky to complete the marathon within the six hours the race course was open. Average pace: 13:09.