Should we be doing cardio in pregnancy? Is it safe to exercise?
The answer is a resounding YES - if your pregnancy is ‘normal’ and your doctor has advised that exercise is fine for you. Always make sure you take note of how you body is feeling before and during exercise, keep hydrated and take regular breaks.
Cardiovascular exercise that safely raises the heartbeat contributes to general health, promotes better sleep, can reduce the possibility of gestational diabetes, can reduce constipation and help with aches such as back and leg pain. The NHS states: “Exercise is not dangerous for your baby – there is some evidence that active women are less likely to experience problems in later pregnancy and labour”. Even more reason for us to be keeping our energy levels up and making time for some exercise. The NHS recommends starting gently and “ Increase this gradually to at least four 30-minute sessions a week”.
In my first trimester I noticed my energy levels were lower and I was getting tired more quickly, so I took note of that and listened to my body - making my runs shorter and taking more breaks. However when I moved into that golden time of the second trimester (I was lucky here - no aches and pains, and feeling strong) I was really able to enjoy my workout again. As my baby grew I stopped running and switched it for uphill treadmill walking, but still at enough intensity to break a sweat. I had been loving lifting heavy weights before I fell pregnant, so I tried to incorporate those into my prenatal routine, reducing the load and being really aware of my breathing as it is not advised to hold your breath in any way when pregnant. I found some exercises that were safe and effective for my abs, and I hope they contributed to the lack of a too pronounced Diastasis Recti (separation of the abdominal muscles - more to come on that in future blog posts!)
What about the rule about heart rate not going above 140BPM?
This rule was specified many years ago and but is now misadvised. The Mayo Clinic states: “If you exercised regularly before pregnancy, there's no need to focus on your heart rate for exercise during pregnancy”. When pregnant your resting heart rate (RHR) is raised, therefore likely to be high during exercise, so the heart rate monitors on cardio machines do not provide an accurate reading of intensity.
How do you know what is the right intensity?
The NHS recommend being at level 12-14 on the Borg Scale of Perceived Exertion which equates to ‘somewhat hard’. This can be measured easily when you workout, by doing the talk test - you should be able to speak normally at all times, although be slightly too out of breath to break into song!