Ive done some crossfit. Jhickman who is a fellow sly guy and member of this board turned me onto it..
Crossfit I am convinced is the real deal. It does require some equipment to totally do their workouts but you can scale things down until you actually get the right equipment. Basically you are doing a different workout every day and it focuses on building strength, endurance, flexibility and speed.
It is hardcore and I would say pretty safe if you scale back the workouts.
I am going to start the Power 90 workout on Monday because I want something regimented for diet and exercise but after that I will go back into Crossfit. Besides power 90 is similar to crossfit where its about building total body strength, FUNCTIONAL body strength.
Ive spent MANY years doing muscle and fitness type workouts and my firm belief is that this is better. Ill give you an example of one of their workouts that anybody can do.
superset of
5 pullups--no rest
10 push ups--no rest
15 squats (bodyweight only---make sure you squat down low enough so your butt is about 20 inches off ground)
Rest
repeat
Do as many sets as you can for 20 minutes and record your time.
THIS is crossfit...its a combination of cardio and strength training...
Im about to do 5 sets of the following.
Run 400 meters...
15 squats. (while holding 65 lbs over your head)
Its an ass kicking workout for sure.
Hope this helps.