Running for two (or three!): The journey of an ultramarathoner across two pregnancies.

There is a lack of evidence regarding the safety of long-duration and vigorous intensity physical activity during pregnancy, such as that required during an ultramarathon. This case study is the first to examine the training, performance, health, and delivery outcomes for an ultramarathoner across two successive pregnancies (one twin and one singleton) that were delivered when the athlete was 41 and 43 years, respectively.. During her twin pregnancy, she ran an average of 91.72 ± 23.17 kilometers across 9.06 ± 2.38 hours per week. Both twins were normal for gestational age and delivered at 37 weeks. Twin B experienced mild hypoxic-ischemic encephalopathy, but made a full recovery following treatment. Twin pregnancy increases risk of this complication and there is no evidence to suggest that it is associated with vigorous intensity endurance activity. During her singleton pregnancy, the participant's distance and pace increased, running on average 157.80 ± 14.69 kilometers across 14.08 ± 1.60 hours per week. She also competed in 5 races including 3 ultramarathons and ranked well, with no adverse events during or following each of the races. She delivered prematurely (36 weeks and 6 days), but her baby was normal for gestational age.