Re: Help! Can't do any compound lifts for 4-6 weeks!
Can you row and use an AirDyne?
If you can row and use and AirDyne or Assault Bike, that is what I recommend. Both of those can absolutely kick your *** and will also give you a full body workout. I can give you a bunch of workouts for those machines which will seriously increase your fitness.
If you are really limited to walking (not running) or an elliptical, I'd say get used to walking on an incline and go for an extended period of time. Doubt it will get your heart rate up into the "speedwork" zone, at least for interval training, but over time on an incline you can probably get your heart rate up.
I'd stay away from the elliptical. It is a waste of time in my assessment. If you can't use an AirDyne, but can use a regular stationary bike, the regular stationary bike would be a great cardio tool.