Exercising Through Your Pregnancy




Exercising Through Your Pregnancy

Exercising through your pregnancy.

Expecting a little baby is the biggest blessing a woman can receive, but being pregnant is not always the most glamourous experience. After the initial excitement of finding out you are expecting the nausea and tiredness start to kick in. Questions whether you should exercise are also going through your mind.

It is important to make informed choices about exercise during your pregnancy. In this blog we will discuss how exercise affects pregnancy and the growing baby. We will also give you some fitness guidelines for each trimester.

Dr James Clapp did a lot of medical research on this topic and he wrote a book called “Exercising trough your pregnancy”. I would recommend reading this book if you need more information.

How exercise affects Pregnancy:

Pregnancy affects many systems in your body and so does exercise. Let’s look at some of the changes that happens when you combine the two.

  • The heart and circulatory system adapt to pregnancy

    • During pregnancy the entire circulatory system adapts to accommodate mom and baby. The adaptions begin as early as the fertilized egg is implanted and the result is that the elasticity and volume of the entire circulatory system changes over night.
    • This creates a problem because suddenly there is not enough blood in the system which causes lower blood pressure. This can lead to unpleasant symptoms such as lightheadedness, nausea, extreme fatigue, cravings, constipation, bloating, frequent urination and sweating.
    • The body takes time to adapt to the new hormones and decrease blood pressure and steadily the body produces new blood to increase blood volume.
    • It’s estimated that a pregnant woman has up to 50% extra blood during pregnancy.
  • Lung and Placenta gas transport

Pregnancy has several effects on lung function that improve the delivery of oxygen to the tissues of the mother and baby. The placenta is designed to maximize this transfer of oxygen and carbon dioxide between mother and baby.

In early pregnancy, the increase in progesterone stimulates breathing, which improves the transfer of gases to and from the baby. It also makes a woman feel short of breath, but her lung function remains normal.

Although many pregnant woman find it hard to breathe deeply, the elevation and widening of the rib cage actually improves breathing capacity and gas transfer to tissues. The effects of training and pregnancy improves aerobic capacity by 5 to 10 % and this is most apparent 6 to 12 months after given birth. It may explain some of the improved sport performance in professional athletes after having a baby.

Regular exercise during pregnancy has positive effects on the growth and function of the placenta that protects the fetus from oxygen deprivation. Studies have shown that placentas of women who exercise regularly through early and mid -pregnancy grow faster and function better than those women who are heathy but don’t exercise regularly.

  • Body Temperature and sweating

Maternal body temperature and many aspects of temperature regulation change dramatically during pregnancy. Interestingly studies found that pregnancy actually reduces the risk of a mother’s temperature rising high enough to bother the baby by improving her ability to get rid of heat through her skin and lungs.

A couple of factors contribute as to why pregnant women can regulate body heat better:

  • There is an increased blood flow to certain areas which raises the temperature, this increase in blood flow cause the skin to “glow” and heat radiates from these areas.
  • Pregnancy lowers the body’s set point for sweating, thus cooling her down when she sweats.
  • Increased blood volume helps to regulate temperatures.
  • Increased breathing capacity helps to regulate temperatures.

Women who exercise during pregnancy can deal more effectively with heat stress than women that does not exercise.

How muscle, ligament and bone adapt

Increased weight gain, enlarging abdomen and lax ligaments due to increased elastin will put more mechanical strain on the back, hips and legs on pregnant women. Numerous studies have documented many positive effects of exercise on muscles, ligaments and bone mass and strength. The effect of exercise should counterbalance the negative effects of pregnancy by improving strength to reduce low back pain and other injuries associated with pregnancy.

Book at Just Physio!

 Call us today you struggle with low back pain during pregnancy. Physiotherapy can bring a lot of relief and we can give you good advice.

Benefits of exercise for the mother during pregnancy:

  • Helps you stay fit and in shape because you will have less weight gain and fat accumulation.
  • It will prepare your body for labor and delivery.
  • Reduce back pain and prevent other injuries
  • Reduce constipation, bloating and swelling.
  • It will boost your mood and energy levels.
  • Promote muscle tone, strength and endurance.
  • Lower your risk for gestational diabetes.
  • Shortened labor
  • A reduced risk of having a C-section

Below are a few guidelines you can follow when you exercise.  Whether you are a beginner, recreational or competitive athlete its important to listen to your body and take precautions as necessary.

Interpreting your exercise heart rate during pregnancy:

There is a lot of debate whether or not to use your heart rate response as a guideline during pregnancy. During pregnancy your heartrate will increase, especially in early pregnancy because your body is still catching up to increase the blood demand. If there is less blood in the system and the arteries are dilated due to hormonal changes it will increase the heart rate. Exercise heart rate at one’s usual intensity will be extremely high because there is not enough blood in the system for the heart to pump the usual amount of blood with each beat. Same thing happens when someone gets dehydrated.

By mid-pregnancy the heart rate will be the same as pre conception and by late pregnancy many women find that their heart rate is lower than before pregnancy.

Many women wonder if it is safe for the baby to let their heartrate go that high, and therefore they believe a pregnant woman should not exceed 70-80 % of her maximum heart rate.

Maximum heart rate is calculated as follows: 220 – your age, so if you are 30 years old, your maximum heart rate will be 190.

If a pregnant woman knows a lot about her heart rate and its response to exercise before pregnancy she can use it as a guideline, but Dr. Capp recommends to rather use the Borg Rating of Perceived Exertion (RPE) scale as it may be a much better index of exercise intensity than heart rate.

The Borg Rating of Perceived Exertion (RPE) scale allows the individual to numerical rate how hard she is working.

The Borg Rating of Perceived Exertion (RPE) scale

Photo credit: https://www.sbfitnessmagazine.com/articles/rate-perceived-exertion-scale/

Fitness guidelines for the First Trimester

Keep hydrated

Beginner group

Ladies that have never exercised before pregnancy fall into this group. It’s important to understand the benefits you get from exercises because it will help you to stick to a program easily. Choose an exercise that is fun to do and that fits into your daily program. Exercise programs that include some weight-bearing exercises with 20 minute of cardio and end of with stretches is a good place to start with. This will help with endurance, flexibility and strength and you will see a noticeable effect on your body configuration.


  • Avoid doing too much too fast
  • Wear appropriate foot wear and clothing and underwear
  • Use the common-sense approach: keep cool, hydrated, well rested, and well fed
  • Don’t exercise in very hot and humid weather
  • Don’t run midday, or exercise in gyms with poor ventilation
  • Avoid saunas, hot tubs and steam rooms
  • Pay attention to hydration and salt intake, don’t exercise without a bottle of water nearby. Urine needs to be almost clear (like water).
  • Avoid letting you blood sugar fall, especially in early pregnancy. Eat small quantities of complex carbohydrates (brown rice, quinoa, wholegrain bread, whole grain pasta, beans) combined with some protein and fat.
  • Eat every three hours plus a bedtime snack
  • Avoid processed tapes of starches and potatoes. They can cause blood sugar to fall rapidly.
  • Avoid exercising within 30 minutes of a large meal.
  • Avoid excessive fatigue – a good guideline is to have 1 hour of quiet time for each hour of planned exercise.
  • Always evaluate yourself for any pain, vaginal bleeding or not feeling well.

Click here for more information on how to start and exercise program.


Recreational group

Women that exercised regularly before pregnancy for fun and rarely competed fall into this group. This group of women already understand the benefits of exercise and they are usually motivated to stick to a health lifestyle. These women usually want improve their sense of well being during pregnancy and improved fitness.


  • Focus on endurance, strength and flexibility when choosing an exercise program.
  • Now is not the time to focus on new skills, speed and balance. It will be hard to maintain in late pregnancy.
  • Balance your exercise load and rest. Rest one hour for each hour of exercise.
  • Pay attention to environmental conditions.
  • Pay attention to eating habits (to avoid low blood sugar)
  • Seek medical help if abnormal symptoms develop
  • Don’t get overheated and overtired
  • Avoid to travel to hotter climates or from sea level to high altitude.

Competitive Athletes

Work with your coach

These athletes are used to high intensity training and they are usually competitive, independent, headstrong and they usually perform far better than people would imagine. Its for this reason that they need assistant guidance from their healthcare provider and their coach. A proper exercise program is necessary to set the limits and pace.


  • Clear goals need to be set between the coach and athlete with regards to:
    • Maintaining or improve basic fitness characteristics in the body
    • To improve sport specific skills
  • Exercise programs need to focus on endurance, strength and Sport specific skills.
  • Check the training equipment every 2 weeks to 2 months to make sure its not hazardous.
  • Pay attention to environmental conditions: avoid hot, humid and poor ventilated areas.
  • Stay well hydrated and drink water regularly.
  • Eat frequently and well.
  • Stay away from fad diets and super vitamins. Regular supplement are fine, but high doses of vitamin A can cause congenital malformation.
  • Follow rest activity cycle plan. Take an afternoon nap and make sure you go to bed early and rise early.
  • Don’t train at altitudes higher than 7500 feet.
  • Don’t ignore symptoms of pain, discomfort and vaginal bleeding.

Fitness guidelines for the Second and third Trimester

During mid and late pregnancy the mothers body changes continually and the baby grows rapidly. So, when you attempt to exercise you need to make sure you evaluate your response of the exercise continually. Either a change in well-being or abnormal physiological responses indicate that the training regime needs to be modified.

Avoid exercise that include:

  • That might give abdominal trauma like (horse back riding, gymnastics, high speed waterskiing, rock climbing, hockey, or the like).
  • Its not the time to compete in competitions

Warning signs when not to exercise through your pregnancy:

  1. A fall in the baby’s heart rate
  2. no kicking 30 minutes after exercise are warning signs.
  3. If you suffer from any conditions like:
    1. Heart and lung disease
    2. Preeclampsia or high blood pressure
    3. Persistent vaginal bleeding during the 3rd trimester
    4. Placenta problems
    5. Preterm labor during current pregnancy
    6. Multiple pregnancies
    7. Severe anemia

Please consult your doctor and do not exercise again until the situation is clarified

In summary:

There are many benefits for mom and baby when you exercise during pregnancy, but it’s good if you understand what guidelines to follow. No matter what your age or what stage you are during your pregnancy, how you feel before, during and after a workout is a good indicator whether you can go on with your exercise routine or not.

Call us today if you need help with a tailor made exercise program!

Book at Just Physio!

– Written by: Adrien Dannhauser (BPhyst, SPT1)