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 yr, respectively. During her twin pregnancy, she ran an average of 91.72 ± 23.17 km across 9.06 ± 2.38 h/wk. Both twins were normal for gestational age and delivered at 37 wk. Twin 2 experienced mild hypoxic-ischemic encephalopathy but made a full recovery following treatment. Twin pregnancy increases the 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 km across 14.08 ± 1.60 h/wk. She also competed in five races including three ultramarathons and ranked well, with no adverse events during or following each of the races. She delivered prematurely (36 wk and 6 days), but her baby was normal for gestational age.NEW & NOTEWORTHY This study provides the first description of a pregnant female ultramarathoner's training patterns, performance outcomes, and health and birthing outcomes across two pregnancies.
Keywords: athlete; endurance; perinatal; twin; ultramarathon.