British Journal of Sports Medicine: https://bjsm.bmj.com/content/58/11/586
One reviewer and I can't see the review (I've a feeling this isn't an open review journal in the BMJ family).
Interesting recruitment criteria for which I can't find additional breakdown re: whether the participants are competitive athletes or "undergo physical training at least three times per week". There's something later about nobody competing at national or international level (unhelpful).
diverse cohort of athletes, with endurance sports representing 36% of the athlete cohort, team sports representing 26% and power sports representing 38%.
I haven't read it carefully but, given the small number of participants (understandable) there's an interesting number of exclusions by failure to have an endocrine profile, transgressing T levels, failing to meet required respiratory exchange ratio.
19 cisgender men (CM) (mean±SD, age: 37±9 years), 12 transgender men (TM) (age: 34±7 years), 23 transgender women (TW) (age: 34±10 years) and 21 cisgender women (CW) (age: 30±9 years)
I don't know what the normal 'failure' rates are for experienced users of metabolic carts and tests but this feels quite high.
Blood measures
There was a significant gender effect on testosterone concentration (F(3–66)=80.6, p<0.001). CM (20.5±5.8 nmol/L) exhibited significantly higher total testosterone concentration than transgender women (0.7±0.5 nmol/L, t(66)= 11.1, p<0.001, figure 1A). Transgender men (24.8±12.3 nmol/L) had elevated total testosterone concentration compared with transgender women (t(66)=11.3) and cisgender women (0.9±0.4 nmol/L, t(66)=10.9, both p<0.001, figure 1A). There was also a significant gender effect on oestradiol concentration (F (3−66)=7.6, p<0.001), with transgender women (742.4±801.9 pmol/L) showing higher oestradiol concentration than CM (104.3±24.8 pmol/L, t(66)=4.4 p<0.001), cisgender women (336.0±266.3 pmol/L, t(66)=2.7, p=0.045) and transgender men (150.2±59.4 pmol/L, t(66)=3.4, p=0.01, figure 1B).
Transgender women’s total testosterone concentration (0.7±0.5 nmol/L) falls within the recommendations for GAHT of ≤1.8 nmol/L,5 and oestradiol concentrations (742.4±801.9 pmol/L) exceed the target of 400–600 pmol/L5 for GAHT. Transgender men’s testosterone concentration (24.8±12.3 nmol/L) exceeds the NHS target of 15–20 nmol/L6 for GAHT, although not the Endocrine Society target of 11–34.7 nmol/L.7
A missing callout comparison in the above is relative testosterone for TW and women. (Authors provide what they term: CM vs TW; TM vs TW and CW.) Then there is an oestradiol set of comparisons.
The general lung function tests are in line with what I'd expect (Table 2) although I could do with more information about the participants (who were the endurance/power performers) and whether they're accustomed to a VO2 max test). And, as for why they've highlighted the countermovement jump in the lower body anaerobic power section…
ETA: several people posted in the time it took me to do the above, apologies for x-overs.