I just think it's important to note that while many kids that continue training (and the bulk of the children of the parents here) CAN handle it, there are many kids that do find it to be too much.
When my 7 year old was having difficulty adjusting, the attitude her gym gave me was that everyone else could do it, why couldn't she, kind of insinuating that the problem was with her. Not my proudest parenting moment, but for a (brief) moment I kind of bought it. She was unhappy with the training hours for the plain reason as she wanted more time at home to play. We switched gyms to a less intensive program and she is happier and still progressing, when she would have quit the sport otherwise. There is nothing wrong with her wanting to play (at 7 !) instead of train.
We switched gyms and decreased hours. I'm coaching her now which isn't ideal but works most of the time. She was an old 4 but repeated and did 3 this year. She will do 4 this year so she's really maybe a year behind where she would have been. Truly though, where she would be had we not made the switch is DONE.
I found her old training schedule they had sent home and she had written on it "I dot wot to do this!" I never saw that at the time but it was sad to see now. I hate that for a moment I was thinking of how I could change HER versus how I could change the situation!
She likes gymnastics, but I'm not sure she loves it, and that's okay! Still plenty of great memories to have and lessons to learn!