Alice Arnold, broadcaster and partner of sports presenter Clare Balding, said Daley's coming out video would help his career.
She told Channel 5 News:
It will make him a better diver, because if you've got that monkey on your back you're worried all the time.
It takes a lot of energy to live a secret life and he doesn't have to live a secret life, and that will improve everything for him and for everyone around him.
Ms Arnold said Daley's move would help other gay athletes.
– Alice Arnold
If you look on social media there is still some very bad attitudes amongst the very young in schools and I think he will help that.
I hope that his coming out will help that a lot.
He needs to talk about it because if he wants to go for a meal in a restaurant with his boyfriend there will be cameramen outside waiting for him, paparazzi waiting for him, hounding him every step that he takes.