I'm very much an "amateur" when it comes to hiking, but decided to give Camelback a try with some friends who hike it regularly. Before starting up the Echo Canyon trail, it's definitely intimidating looking up at the mountain. The nice part about the Echo Canyon trail is that there's a parking lot and nice facilities at the start of the trail.
The first portion is a steep incline. It's a great workout and gets your heart pumping. After that portion, there are some stairs that you climb. Fine... nothing crazy. Then... you come to the first "rock slide." It's nothing more than a steep rock slope with a few metal railings to pull yourself up with. I made it to the top of the first rock slide and had to stop (I'm exactly what you'd consider "healthy" yet...).
Even though I didn't make it to the summit, it was still a great workout and an enjoyable experience. There's a reason it's classified as "extremely difficult," but ultimately I think anybody should try it at least once. Go as far as you can... that's what I did!