There is a problem with this, irrespective of physiology.
As there are fewer women who race than men, in order to get a full field of riders, women’s races have a much wider range of abilities than men’s races. If you’ve ever watched, on the ground, not on telly) a major women’s race e.g. national championship or European championship, you would have seen that the women’s race has blown apart after a couple of laps, compared to the men’s race which stays together until much nearer the finish. This is because difference between the fastest and slowest women is much greater than between the fast and slow men. And that’s on a race that’s half the distance of the men’s race. So you can imagine how spread out a women’s race would be racing the men’s distance. I’ve no doubt the world’s elite women could complete a 3 week grand tour but there simply aren’t enough elite women to make full field of 180 riders.
There is a problem with this, irrespective of physiology.
As there are fewer women who race than men, in order to get a full field of riders, women’s races have a much wider range of abilities than men’s races. If you’ve ever watched, on the ground, not on telly) a major women’s race e.g. national championship or European championship, you would have seen that the women’s race has blown apart after a couple of laps, compared to the men’s race which stays together until much nearer the finish. This is because difference between the fastest and slowest women is much greater than between the fast and slow men. And that’s on a race that’s half the distance of the men’s race. So you can imagine how spread out a women’s race would be racing the men’s distance. I’ve no doubt the world’s elite women could complete a 3 week grand tour but there simply aren’t enough elite women to make full field of 180 riders.