Get your doctor's approval. While it is absolutely safe for the majority of pregnant women to exercise throughout their pregnancies, there are some situations in which the opposite is true.
Do not get overheated. Be smart about this! You know when you are uncomfortably hot, so take appropriate measures right away when you feel that you are approaching this state. Drink plenty of cold fluids, exercise indoors when it is hot and humid, use a fan, and do not over exert yourself. (30, 31, 32, 33, 34, 35, 36, 37, 38)
Avoid isometric exercises. Isometric exercises have a large effect on blood pressure, more so than other strength moves. (3, 39)
Avoid very heavy weights when strength training. Focus more on endurance by lifting weights light enough that you are able to complete at least 12 repetitions. (3, 39)
Avoid exercises completed in the supine position. This puts pressure on the vena cava restricting blood flow. (39)
Be aware of joint pain. While scientific evidence shows no concerns with pregnant women engaging in high impact activities, you may notice more stress on your joints as weight gain progresses. If this becomes a problem, switch to activities such as stationary cycling, swimming, and others that have less impact. (3, 39, 64, 65, 66)
Avoid activities that could result in falling. This includes riding a bike that is not stationary, horse back riding, and gymnastics. (39)
As long as your doctor has approved you for exercise, guidelines are exactly the same for pregnant women as they are for everyone else. These recommendations are five days of moderate activity for 30 minutes or three days of vigorous activity for 20 minutes.
Also, at least 2 days of strength training. (3, 67, 68)
Judge your appropriate intensity level based on how you feel. If you are familiar with Borg’s Rate of Perceived Exertion (RPE) (look for a future blog on this), you can aim for a rating of 12 to 14. If you are not familiar, the best thing to do is to be sensible. You shouldn’t work so hard that you are completely breathless and at the point of exhaustion. Aim for an intensity that allows you to speak in sentences and feel good throughout your activity. Unfortunately, there is absolutely no conclusion on a safe heart rate zone. No heart rate has actually been found to have a negative impact on mom or baby. If your doctor tells you that you should keep your heart rate below 140 bpm, ask another doctor’s opinion. That advice is completely arbitrary and has zero scientific evidence. In fact, one of the leading physicians in prenatal exercise research, Raul Artal, M.D., has written articles cautioning doctors about giving this advice to their patients. (3, 15, 39, 68)
For more information, stay tuned for other articles on this subject. Also, these books are easy reads written by leading researchers/physicians in prenatal exercise that give a lot of great information. Although both books are great, the first is a little older and doesn’t include some of the more recent research.
Artal, R. & Subak-Sharpe, G.J. Pregnancy & Exercise. New York, New York: Delacorte Press: 1992.
Clapp, J.F. Exercising through your pregnancy. Omaha, Nebraska: Addicus: 2002.