If you have a knee injury, staying in shape without making the knee worse is a major concern. Cardiovascular exercise is important for general health and also aids in healing injuries by providing freshly oxygenated blood cells to the area. Many exercises that get your heart rate up — such as rowing, cycling, jogging and using an elliptical trainer — use both legs and may be impossible with a knee injury. Activities involving primarily your arms will enable you to keep up your cardio workout regimen.You should check out some rowing machine reviews here: http://rowingmachinely.com to find the right one for your needs.Like others have mentioned, a spin bike might be a great option for you and they actually have a spin bike/ rowing machine hybrid product made by Stamina.
I am an advocate of aqautic exercise for restrengthening injured runners and athletes. I also use it to train my clients that are not injured. Aquatic exercise is used in almost all professional sports programs for prehab, rehab and postrehab situations. And equestrian (horses) training facilities spend big money to construct pools/tanks for use to train multi-million dollar horses, both as training and rehab for injuries. It is even possible to train for power and hypertrophy using aquatic exercise.
If you think that aquatic exercise is too wimpy for you, I invite you to visit me on the Big Island of Hawaii. I’ll change your mind. This is one of the course formats that I teach as CECs for fitness professionals. Check out my website – www.hawaiifitnessacademy.com . And I would be happy to just meet any fitness professional coming here on vacation. This is my passion and I like to spread the Aloha in the fitness community.
First, seek professional help on rehabilitating the knee. We need more specific information to help with that aspect. When exactly did the injury occur? Precisely what are you doing to rehabilitate now? Specifically which exercises cause no pain and specifically which exercises cause pain?
For CARDIO, non-impact exercises are what you are looking for. Swimming and rowing are best as those are the 2 functional, non-impact, cardio exercises you can do. I would suggest biking, but that depends on your range of motion in the knee.
What was the nature of the injury ? Have you been cleared to workout ? If you have, it all depends on how much flexion, extension you have at that joint. As much as I not a believer in Lifecycles, I think there is a place for them because you can increase/decrease the tension. Find something that’s low impact.