I'm sure someone in the past has asked this already, but it's my turn now I guess.
I don't have straddle split flexibility yet and I know that Manna exercises and pressed handstand require that but I'm not sure what's the best way to go about achieving that kind of flexibility in terms of what to do, how often etc.
Take for example something simple like a straddle sit-up, which I remember not being able to do very well in my youth. Still can't, how do I develop that? I was stubborn back then.