Monday, October 28, 2013

Dehydration causes uterine cramps. Science.

Every so often during my early morning treadmill hillwork, I get muscle cramps when running.  

No, not leg or back cramps or even a side stitch.  

I experience what feels like menstrual cramps- especially during a real tough workout.  I thought maybe at first it was due to my posture, or maybe a case of the Bubblies, but it happened again yesterday on my 3 miles of steep hillwork, where I was holding a pretty quick pace, the day after my PR 10K.  I thought maybe my rectus abdominis was sore from some ab work a few days ago, but no- this was exactly like a menstrual cramp, and it lasted a few minutes, but was so bad I had to stop running and drink water until it washed away.  The funny thing is, whenever this happens, it's never during that time of the month, it's usually in the week or two preceeding it.  I think. 

So I did some research into my chief suspect:

Turns out, there are lots of internet voices out there who have dealt with this same situation and unfortunately been sneered at by their primary care provider, with no help!

But I can help with what I've learned.  I hope!!

It's all in our brains, to begin with, well...sort of.  Here's our pituitary gland:  It's less colorful in real life. 
Not a scrotum, but yes, that's a uterus.  Grumpy one!
 The posterior pituitary produces 2 hormones as shown above: ADH (antidiuretic hormone) and oxytocin, and as they are made in the same factory, these chemical structures look very similar to our body.  

ADH is produced when we are dehydrated, and acts on our kidneys to help us stay hydrated by decreasing the amount of water we eliminate in urine, hence "anti-diuretic."  

Oxytocin acts on the uterine muscle.  It's primary purpose it to cause uterine contractions for baby delivery!  You may have heard of pitocin, or even used it to induce labor- it's based on the hormone oxytocin.  

When we are dehydrated, like during an especially strenuous aerobic workout, our uterine oxytocin receptors see the extra ADH and think it's oxytocin and commence cramping.  When we then drink water, our body no longer releases the ADH, and the spillover to our uterus stops.  Yay, no more cramping!  Save that for when it's actually my period please.  Actually, please don't save it at all :)

By this same logic, staying well hydrated during your period can ameliorate those cramps. 

This is exactly why pregnant women should stay hydrated, especially when feeling crampy!  And with the holidays nigh upon us and August and September the months with the most birthdays, I'm sure some gals out there might use this information in the near future :)

I also wondered why this cramping usually only occurred a week or two before my period, similar to what many of the anonymous gals found on some women's health websites- and this study here found that in nonpregnant women, during the pre-menstrual (the two weeks before your period) phase of the cycle, ADH is four times (!) more potent than oxytocin in causing uterine cramping. What a naughty little chemical this ADH is!

Wow, do I ever feel like drinking more water before heading to my early morning workouts- overnight dehydration certainly plays a role, too.  And I'm pretty sure this dehydration situation is why I felt these cramps yesterday.

I hope this helps those who have been turned away and made to feel that their pain was unimportant.

Of course, persistent abdominal pain should always be checked out with your health care provider.   

Please tell me I'm not the only one out there with this??