In my last post, I whined about the repercussions of taking aromatase inhibitors (in my case, letrozole) as a way to diminish the amount of estrogen in my body, for the purpose of reducing the risk of breast cancer recurrence.
While I also mentioned letrozole’s effects on my exercise habits, in this post I wanted to drill down on one aspect in particular: muscle loss.
Before I go further, I need to add a disclaimer. Since the time the first photo was taken (the morning before my first chemo infusion), three and a half years passed and I went through menopause. Notably, the menopause was pharmaceutically-driven, starting with tamoxifen and then, after my hormone levels were low enough, continuing with letrozole. However, my body now is dealing with the same aging effects as someone who had transitioned naturally.
Except that my transition came before its time.
The below photo is from April 27, 2017, before I headed to the infusion center for my first dose of chemo. I had been training as normally as I could, under the conditions of lumpectomy and port placement that I wrote about here, and finding work-arounds for exercises that I’d been told not to do.
While I lost some size and strength throughout my chemo infusions (here are all the photos), I was able to bounce back and had a particularly strong 2018 (sorry, don’t have good photos of that). But as the endocrine therapy with tamoxifen continued in 2019, to be replaced by letrozole in 2020, I could feel the effects of low estrogen.
On December 11, 2020, I struck the same pose again for sake of comparison.
As far as muscle appearance is concerned, I have experienced a slow downhill slide. My shoulder is not as peak-y, the biceps itself has decreased in size and I even find it more difficult to hold this muscular contraction. In addition, there’s more looseness in my skin, particularly at the back of my arm, which in part may be due to loss of collagen, also affected by estrogen levels (nice dermatological review by Shah & Maibach, 2001, Am J Clin Dermatol).
I’m busting my butt trying to increase the amount that I’m lifting, but I’m not making progress. Not surprisingly, the decrease in estrogen plays a role in this. As stated by Chidi-Ogbolu & Baar (2019, Front Physiol), “estrogen improves muscle mass and strength, and increases the collagen content of connective tissues”.
It makes sense then that lack of estrogen is going to be detrimental to maintaining muscle. To that point, Kitajima & Ono (2016, J Endocrinol), working with animal models, have found that “estrogen insufficiency leads to muscle atrophy and decreased muscle strength of female mice.”
Not just mice, obviously.
This information comes as no surprise to any woman who’s gone through menopause, I’m sure. But the experience of being slammed through menopause instead of having the opportunity to transition more gradually is yet another frustrating way that having cancer pulls the rug out from under you and reminds you that you are not in control of your life.
Slowly, yoga is becoming more important in my life and my view of fitness is changing. Good thing too, since I can’t keep beating myself up like this.