One of the big concerns for your baby’s health when exercising is fetal temperature and overheating. The temperature of the baby is usually hotter than the mother’s, and it is often difficult for the mother to correctly estimate the risk of overheating.
Overheating the fetus, especially during the 1st trimester, can have serious effects and ACOG guidelines state that the maternal core temperature should not exceed 38C. Vigorous physical activity for sustained periods of time increases the core temperature, and in nonpregnant women 30-60 minutes of strenuous exercise can increase the core temperature to 39C. The short answer is – almost any! It doesn’t really matter what type of exercise or activity you do, it will have the risk of causing your core temperature to rise above safe levels if you exercise too strenuously or in particularly hot environments. That is why you need to take precautions to avoid over heating and be careful to monitor your exertion levels (see our article on heart rate limits) throughout a training session. So with all types of exercise take care to keep cool. Swimming is generally an excellent choice for reducing the risk of overheating, but even then care must be taken. Aside from carrying around a thermometer all day it will be difficult to get an accurate idea of your core temperature! Instead, aim to:
• keep cool by staying well hydrated
• avoiding exercise or activity on hot or humid days
• wear light and loose fitting clothing
• use fans and air conditioning during hot weather
• avoid saunas, steam rooms, spas, or hot baths
To find out more about overheating during pregnancy, or exercising before or after pregnancy please contact us!
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