Zwift Racing

I`m new to racing on Zwift. Just finished my second race on Zwift Category B - is it me or holy crap are people really incredibly strong? Like really strong.

The first two times I tried to keep up on Category B and C, I was dropped after 20 minutes and ending up quiting in frustrating but this time I was able to finish, which I`m proud at.

Have people found that supplementing training with racing now and then helps with their fitness?