When some people first sign up for CrossFit, they ask if it's necessary to keep their membership at the "regular gym" so they can still lift weights (i.e. do isolation exercises like bicep curls and leg extensions) or do cardio (spending mind-numbing hours on the elliptical or treadmill).
If you stick to a CrossFit schedule you will do "cardio", strength training, agility work, plyometrics and gymnastics regularly (and in combination with one another). Your workouts will be varied so your body will never adapt to a routine. You will be performing multi-joint, functional exercises instead of isolation movements – so, you will move like as your body is designed to move and you will be developing muscles you never tapped into before.
So, NO. You don't have to keep you gym membership. It's not necessary, or even advised, to do extra weight lifting or cardio. You don't need machines…you will become one! (of course, if you do a sport, practice it!)
The beauty of CrossFit is that you get in the best shape of your life in less time. Rob and I, and many of our members, used to spend two hours a day in the gym, lifting weights and using cardio machines. We are all stronger, faster and more functional now and we log in less workout hours.
Quality and intensity over quantity, baby!
Workout of the Day:
Five rounds for time of:
Row 500 meters
12 Power clean 135/95
15 Thruster 95/65