Hi Susan. I am quite familiar with Crossfit. Like all types of exercise it will work well for some people and not for others. Keep in mind that the Crossfit gyms here in the States might have a different vibe/attitudes and/or training of the affiliates. So what I'm saying here is from my experience with Crossfit gyms here in the US.
I think Crossfit is great for people who are already quite active, have a strong core and good body awareness. I love the concept of changing the workouts continuously, using the whole body to do exercises (not just one muscle group), using high intesity activity for a short duration to stimulate growth and change. Especially in a body that is already fit and needs something a little extreme to push it hard enough to create change.
What I don't like about Crossfit are the injuries that I see in my clinic. It seems like people get thrown into heavy and intense exercise before they are ready to do it or before they've learned the form. For example, I knew a lady go to Crossfit and after only doing 5 form practices she was asked to do box jumps to a height of 20 inches as many times as she could in a given time. She was being strongly "motivated", tried to do it and ended up straining a deep muscle in her hip. I've seen people at our Crossfit gym trying to pump out fast push-ups with terrible form, back sagging and no form correction given or adjustments made for their current strength level. I could give you pages worth of examples like this.
If you go to Crossfit, be prepared to be pushed very hard. Be prepared to have a "drill sargeant"-type standing over you and using quite strong verbal encouragement. It is definitely not for everyone. But there is a population that it works well for and who seem to love it.
I hope that helps.
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