Exercises » 2nd Trimester Fitness » Cardio Vascular
Cardio Vascular (CV) exercise is essential for general fitness and health.
It builds stamina, strength and pumps more oxygen around your body. It burns calories and increases your metabolic rate. This effect lasts long after you have completed your exercise session.
Yet despite the obvious benefit to our health, many pregnant women are still reluctant or unsure about if and how to CV exercise in pregnancy.
So let’s look at the physiological facts...
The effects of CV exercise on you and your baby:
CV exercise increases your heart rate and makes you more breathless.
During CV exercise when you are not pregnant, there is an increased demand for oxygen to be pumped around your body; especially to your heart, lungs and working muscles.
However in pregnancy the body cleverly alters the priority of your blood flow and makes the heart and reproductive system the foremost important priority, thereby safeguarding blood flow and oxygen to the placenta and baby.
Therefore your body’s exercising or working muscles are definitely more likely to ‘give up’ and you simply won’t be able to physically carry on exercising, well before any risk of oxygen blood flow is a potential problem to the baby.
Also as mentioned in the cardio vascular information section, during pregnancy blood volume increases by a whopping 30-40% (12-13 pints) and within this an extra 20-30% is extra oxygen carrying red blood cells. So there is a more than sufficient blood to supply you and your baby and therefore no need to worry that exercise will reduce oxygen to your baby.
In fact studies show that CV exercise increases oxygen, pumps it around your body more effectively and actually increases the efficiency of the placenta. All of which provide the best possible environment of oxygen and nutrients for your developing baby and your own health.
So let’s look at some reasons & popular myths which may be stopping you from exercise...
CV exercise may cause miscarriage
Exercise in early pregnancy has not been linked to either an increase or decrease in pregnancy. However research has shown that women who remain active and exercise throughout their pregnancy are less likely to have complications during both pregnancy and birth.
CV exercise may cause me and my baby to overheat
Overheating when exercising is never a good idea as it can lead to dehydration, loss of co-ordination, dizziness and fainting. However during pregnancy your body cleverly makes adaption’s to your inner thermostat so that you are less likely to overheat or transfer heat to your baby. You sweat more easily (charming), more blood is diverted to your skin for better evaporation (and you have a larger skin area due to your bump). Plus your respiration rate increases which also help you keep cool, rather like a dog panting! So creating an ‘inner oven’ is not going to be a problem.
However you should always follow sensible guidelines and listen to your body:
- Don’t exercise in excessive heat (Gobi desert at midday is not a good idea!)
- Drink plenty of water to stay hydrated and take a ‘cool down’ break if you feel you are getting uncomfortably hot
- Keep your Intensity Scale to a maximum level 7
- Don’t exercise if you have a temperature or are unwell
- Wear layers of breathable fabric clothes that you can peel off as you warm up
CV exercise may cause my waters to break
The membrane which holds the waters (or amniotic fluid) is strong and able to withstand tension. Waters generally break at the onset of labour or when the cervix starts to open, which sometimes happens prematurely. Therefore impact exercises such as running, step aerobics or jumping will not be the cause of them breaking. However if you’re not used to this higher impact style of exercising then starting them once pregnant is not appropriate for many reasons. So stick to low impact CV exercise such as walking, swimming, X Trainer etc.
CV exercise can affect my baby’s heart rate
CV exercise will cause your heart rate to rise and the baby’s heart rate may also elevate slightly whilst you are exercising. But these heart rate changes are a normal response to CV exercise and do not cause harm or distress to the babies well being. It is not the same as an elevated baby’s heart rate in response to a stressful complication.
However maintaining an intensity scale to a maximum level 7 is both the safest and most effective guideline for you both.
Recent research shows that babies whose mothers CV exercise regularly during pregnancy may have healthier hearts. Researchers found that the resting heart rate of babies whose mothers CV exercised was on average of 10 beats per minute slower, indicating a stronger heart muscle and more efficient CV system.
CV exercise will ‘rob’ my baby of nutrients as I will be using them as fuel to exercise
As already mentioned CV exercise actually helps circulate extra volume of nutrient rich blood to the placenta and helps it work more efficiently. Therefore the delivery of nutrients to your baby will be even more efficient. Your body prioritises the baby’s energy needs over your own so make sure you have regular balanced and nutritious food to avoid your own fatigue and poor health.
So now to look at what sort of CV exercise is going to be most suitable and effective for your stage of pregnancy click here