It seems that estradiol based HRT will, in time reduce most peoples strength and muscle mass, but there are factors which will affect this. If genetics has given you naturally large muscle mass, the reduction from HRT may be less, and age can also affect results.
Studies have shown that within the first year on HRT, blood chemistry changes so that trans women have equivalent haemoglobin to cis women. This limits ability to carry oxygen to muscles, and as most have greater muscle mass than cis women, it actually causes a disadvantage in performance as larger muscles take more of the energy producing oxygen just to stay healthy. This oxygen deficit affects endurance more than short cycle strength.
I have been on HRT for over 7 years, from age 65, and strong genetics for strength and muscle mass. I have lost little muscle mass, and compared to others my age in my gym group, I work with higher weights than all the women and men. I cannot wear sleeveless tops as my deltoid muscles stand out, and I get looks from checkout staff at my bicep flex when lifting shopping bags. My endurance loss has been minimal also, and at 72 years old, I can still swim 3000 metres non stop at my local pool. I have had almost no Testosterone in my system for 7 years.
So, while HRT will reduce strength and muscle mass for most trans women, not everybody benefits.
Hugs,
Allie
