At 5 years old they can start using ballet barre and get familiar with it. They should not be forcing turn outs or doing grand pleas. They can learn stands, steps, body posture, vocabulary, routines, center work before 5 years old. Doctors recomended to wait until 9 years old to start a real dance training. This would avoid any anormaliy deformation on the legs.
Talaria's teachers come to teach after a day at work some of them come from far distances. For the love of dancing. I do the same. Yes, I am tierd sometimes, anyway, I come to dance, and I get energy from it. The secret is warm up and very important is to cool down with deep stretching. It help not to feel sore and more.