I have bad knees..

I can't even go 20 minutes... only maybe 5-10 without needing to sit unless I have a shopping cart to help take some weight off my one knee (I also have hip pain from a slipped disc). What I've been doing the past month is weight/resistance training with a bowflex pr1000 to help strengthen my muscles, it's been helping me strengthen my core and leg muscles to better support my knee. Yesterday I walked around Costco for 2 hours (with a cart), something I never would have been able to do a month ago!

This week I'm also going to start doing DDP Yoga, it has minimal joint impact and provides modifications for those not able to do full moves!

break your exercise into segments... walk the first thing after you get up, if it is only 7 min out and 7 min. back... in early afternoon, try one of tha slow count of e exercise regimine, pool etc others have suggested, again ..what ever you can tolerate... and just before sleep do full body isometrics... resting on your bed... tighten the muscle groups in succession starting with the lower legs/ calf down to feet ... To start.. tense muscles , hold for a slow count of 5, release slowly.. repeat 5 times, work up the body with each group of muscles.. These exercises will build your strength and rev up your metabolism for several hours of the night... according to our nutritionist..20 yrs ago...:>) Worked for me.

Use the ones already posted, and @ night do isometrics...will boost metabolism during sleep hours.

I have very bad knees too, but my knees do not prevent me from walking.

I used to do chair yoga classes. Many rec centers offer chair yoga classes. You may be able to buy a DVD from Amazon.com and do these exercises in the comfort of your home.

I also used to do water aerobic classes in very warm water. If the length of the swimming pool is shallow enough, you may be able to do some walking while in the water. I recommend swimming shoes for water exercise classes and walking in water.