I'm completely confused, but find this conversation so relevant to what I'm going through right now.

I'm working out 3 times a week at a gym (a college class). I do 45 minutes walking on a treadmill, keeping my heart rate between 120 and 140. I'm 45 and weigh 197. I've been waiting for the weather to get better so I can ride on the off days, so after that happens this may all be moot. I never intend to race--I just want to lose weight and be healthy and able to ride as much as is fun.

My weight loss is really slow. I've lost 10 lbs since Christmas. I'd like to see it increase a little. I can't run on the treadmill, which would be the only way I could get my heart rate up higher...my knees won't take it.

Should I do something else and get my heart rate up--elliptical trainer, exercise bike--or just keep on walking?

Thanks!
Karen