I don’t really follow this. In the data I’ve seen, HRT brings trans women halfway between cis men and cis women. Janssen et al 2000 does not contain any trans women, and the place you are quoting from in the linked report is kind of convoluted and since the report has already been misleading one time I don’t really feel like wasting time following the report’s argument. Please lay out the argument for this if you want me to believe it.
Here is my interpretation. The relevant data are contained in Table 6 of the 2022 report on page 25, and show that the relative muscle loss caused by 12 months of feminizing HRT in sedentary trans women is around 4 percentage points. Table 1 of Janssen 2000 gives the normal distributions the 2022 report seems to be referring to: for cis women, mean 30.6% and SD 5.5%; for cis men, mean 38.4% and SD 5.1%. This supports, I think, both your claim that a year of HRT puts trans women at about the halfway point and the 2022 report’s claim that this is nevertheless “within the normal distribution.” That’s a mathematically imprecise claim but I think they mean “within one sigma.”
I think all this is a wash. In particular, I agree with your halfway-point claim at 12 months, but disagree with it on longer timescales. I would like to see a paper examining a longer timescale.
I certainly have the sense it could. But those comparisons are in sedentary people, not athletes, and it’s also possible that out in those tails training causes the differences to mostly disappear.
This has been a nice exercise but I think it’s tangential.
Here is my interpretation. The relevant data are contained in Table 6 of the 2022 report on page 25, and show that the relative muscle loss caused by 12 months of feminizing HRT in sedentary trans women is around 4 percentage points. Table 1 of Janssen 2000 gives the normal distributions the 2022 report seems to be referring to: for cis women, mean 30.6% and SD 5.5%; for cis men, mean 38.4% and SD 5.1%. This supports, I think, both your claim that a year of HRT puts trans women at about the halfway point and the 2022 report’s claim that this is nevertheless “within the normal distribution.” That’s a mathematically imprecise claim but I think they mean “within one sigma.”
I think all this is a wash. In particular, I agree with your halfway-point claim at 12 months, but disagree with it on longer timescales. I would like to see a paper examining a longer timescale.
One sigma feels like it would make a huge difference for something like competitive sports which is mostly about the tails of the distribution.
I certainly have the sense it could. But those comparisons are in sedentary people, not athletes, and it’s also possible that out in those tails training causes the differences to mostly disappear.
This has been a nice exercise but I think it’s tangential.
For all I know, it could be that training causes the differences to shrink, but it could also equally well be that it causes them to grow.