Friday, March 5, 2010

Early Pregnancy Exercise Safety

IMG_3843I have just started to train a new pregnant woman at the gym- she thinks she is 7-8 weeks pregnant. I noticed during the assessment she was getting breathless quick and kept referring to how deconditioned she is. I told her the facts on what is happening to her body while exercising during this early stage of pregnancy.

Things that are happening in your pregnant body
1. Your blood volume is increasing up to 40% more
2. Your blood vessel may not have dilated enough yet to catch up with the elevated volume so spikes in heart rate with little effort occur. Your blood vessels are dilating to accommodate volume. This depends on what week you are in.
3. More blood to your periphery

The difference in your early pregnant body during exercise
1. Breathlessness
2. Dizziness
3. Sweating

It is critical in your first trimester to work in your age appropriate heart rate zone. The neural tube is developing and an elevated core body temperature may hinder proper development. Due to your blood volume changes listed above an your bodies accommodations, elevated core body temperature is easily achieved.

TARGET HEART RATE ZONES (taken from par med x for pregnancy)
The heart rate zones shown below are appropriate for most pregnant women. Work during the lower end of the HR range at the start of a new exercise program and in late pregnancy.

Age Range Heart Rate
< 20 140-155 bpm

20-29 135-150 bpm

30-39 130-145 bpm
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