Menstruation & Inversion

An interesting email from reader, Karen:

"During a general discussion about Pilates with a friend who practices Yoga, she asked me if female Pilates students are told not to do similar inverted exercises like the plough (roll-over / jack-knife / short spine), head / shoulder stand during menstruation. I told her no, and I asked her why not. She replied that her Yoga instructors had explained that the flow of energy during those days will be blocked during inversions and may cause giddiness.

I did a quick search on the internet, and there are basically 2 schools of thought :
Not OK (http://www.yoga.com/ydc/enlighten/enlighten_document.asp?ID=74&section=9&cat=93)

It's OK (http://yogapilates.suite101.com/article.cfm/practicing_yoga_on_your_period) (http://www.yogajournal.com/basics/831).

Presently ignoring the philosophy behind Yoga, I hope you would share thoughts as female Pilates instructor on the topic, and whether a female body executes the Pilates exercises differently (from your personal observations) during the different stages of the cycle.

Thanks,
Karen"

First of all, I need to thank Karen for bringing up this topic for discussion. I myself was confused when I first started off in fitness industry too.

In the past, it was believed that performing inversion exercise during menstruation may lead to 'retrograde menstruation', where menstrual blood tissues 'leaks' out of the womb thru the fallopian tube openings into the pelvic area. These blood tissues then stick to pelvic organs and continue to grow and respond to fluctuation of female hormones throughout the menstrual cycle, causing symptoms of endometriosis. Thus women were advised to avoid inversion exercises during menstruation.

However, retrograde menstruation happens natually in almost all women, but only 3-10% of them suffer from endometriosis. So there must be other factors (e.g. genetic and immune dysfunction) that actually cause the condition. And inversion exercises should not be blamed on its own.

Others were concerned that inversion exercise might cause vascular congestion, leading to heavier menstrual flow. However vascular congestion can also be aggravated by standing and other physical activity, not just inversion pose alone.

My take is, inversion exercise is safe to be performed during menstruation, as long as you don't hold it for too long (seriously, what's the point of holding yourself long in the inverted pose?!). As with any other exercises, one should listen to their body and see what works and what doesn't for their own body. If you have much heavier menstrual flow or pelvic pain after doing inversion exercise, then do less or avoid them completely in future.

*To side-track a little, inversion exercises are absolutely NO-NO for people with high blood pressure, stroke, post-natal and glaucoma.