Heart rate during pregnancy should be monitored when exercising to avoid over-exertion. Keeping fit during pregnancy has wondrous effects on pregnancy and childbirth. Exercising must be done in moderation during pregnancy, however, in order to ensure that the mother-to-be is not over-exerting herself. Dramatic spikes in heart rate and core body temperature can have negative effects on the pregnancy and on the baby.
Target Heart Rate while Exercising During Pregnancy
Early recommendations from doctors and medical practitioners were to limit a pregnant woman’s heart rate during exercise to 140 beats per minute. This recommendation now seems to be outdated, as more health care practitioners say that it is useless to pin an exact number on every pregnancy. Every woman’s inner chemistry is different, as is her fitness level. Recommendations now appear to be focused on an individual pregnant woman’s self-monitoring. She should monitor her heart rate by perceived exertion during exercise.
Increase in Resting Heart Rate in Pregnancy
Pregnancy naturally increases a woman’s resting heart rate even before engaging in exercise. This increase varies anywhere from an extra 10 to 20 beats per minute. This is because of the increase in the quantity of blood that the heart is pumping. More blood volume inevitably translates into more heart beats per minute to accommodate this increase. In addition, more oxygen is required during pregnancy. As such, the heart needs to beat a little faster to enable lung fitness to adjust to this increase. Maternal heart beats directly influence how fast the baby’s heart beats as well.
Previous Fitness Level as a Factor Affecting Heart Rate
There are other factors besides pregnancy that can affect a pregnant woman’s heart rate. Fitness condition is an important one. If a woman was already very physically fit and active prior to getting pregnant, then perhaps her resting heart rate may be lower than that of a sedentary woman. If this is the case, the fit pregnant woman will be able to work a little harder during exercise because she has more room to increase her heart rate level, and her heart and lungs are more capable of working more efficiently.
What Should Be Cause for Concern?
Part of the reason why medical practitioners worry about heart rate during pregnancy exercise is the spike in core body temperature. Over-heating can be dangerous for the baby, and can result in birth defects and other serious issues. This is why pregnant women are generally advised against taking hot baths or sitting in saunas. Inner body temperature increases during exercise, which is indirectly caused by a dramatic increase in heart rate.
Although medical associations are no longer necessarily stating a specific number of heart beats per minute for pregnant women to stay below, it is still generally advisable not to exercise to the point of exhaustion. Pregnant women are advised to rate their perceived exertion on a scale from one to 10 – one being very low exertion, and 10 being maximum exertion. A pregnant woman should be working at a level between five and eight on a scale of one to 10. If a pregnant woman is unable to carry a conversation during exercise, then she is working too hard, and most likely has a heart rate that is too rapid.