Question

Mary Smith is a marathon runner and has been training for the Boston Marathon for a year. She recently found out she is pregnant and the marathon is less than two months away. Her obstetrician says she should withdraw from the marathon. Why might this be? Consider the cellular use of oxygen and how that might be affected by a fetus.

Answer 1

Pregnant women should avoid marathon running due to the impact it can have on the fetus's oxygen supply and the strain it puts on the mother's cardiovascular system.

Step-by-step explanation:

Pregnant women should avoid strenuous activities such as marathon running because it can impact the oxygen supply to the fetus. During marathon running, the body requires a high amount of oxygen to meet the increased energy demands. However, the growing fetus also requires oxygen, and the increased demand from both the mother's muscles and the fetus can result in inadequate oxygen delivery to the fetus. This can have negative effects on the baby's growth and development.

Additionally, marathon running can put a significant strain on the mother's cardiovascular system. During exercise, the heart pumps more blood to supply oxygen and nutrients to the muscles. In pregnancy, the mother's blood volume already increases to support the fetus, and the added stress of marathon running can put extra strain on the heart. This can increase the risk of complications and compromise the mother's health.