Why exercise feels different during pregnancy
Gestational hormones can cause your body to undergo significant anatomic and physiologic changes to create an optimal environment for the fetus. Exercise is encouraged throughout pregnancy because it provides benefits to you and your fetus, but you’ll notice some things feel different.
Your heart rate increases in the first trimester as a result of the increase in circulating gestational hormones. Your blood volume increases by approximately 50% to accommodate the needs of your body and fetus. In the second and third trimester the heart rate is elevated to maintain a normal blood pressure.
You breathe more deeply because of the increase in gestational hormones. Breathing may also feel more difficult as a result of your growing uterus taking up more space and putting pressure on your diaphragm.
You get flushed and sweat sooner when you exercise.
Pregnant women tend to divert more blood flow to the skin to allow heat to dissipate more quickly, this prevents any dangerous increases in fetal temperature.