There was a study done that indicated an approximate loss of 10 percent performance in endurance events, putting hormone controlled trans women on par with cis women.

That "study" was a 2015 paper about 8 trans-identified male long distance runners who self-reported that their times in distance events had gotten slower after "transition." One of the athletes included in the "study" was the author. The intervals between the "before transition" & "after transition" times these runners self reported varied greatly - in one case it was 29 years.

That "study" has been widely debunked, & recently the author of it said its findings were "flimsy" & have not been borne out by research since.

Males on T suppression for 12 months lose 5% of their muscle mass & strength advantage. Since the male advantage in sports ranges from 12% to close to 50%, there's no way this puts T-suppressed post pubertal males on a level playing field with female athletes.

The author of that "study" has also acknowledged publicly that even after 36 months of T suppression, males who identify as trans retain most of the male advantages they have over females in sports.