I used to weigh 220 about a year ago. My only cardio involved a heavy bag and a stationary bike. I used to somewhat have knee pain but I think that was due to stress on my knee from being overweight. I currently weigh 160-165. The lowest I've been was 142 in January. I lifted weights but I'm not so sure if it'll help with your weight loss. I'm not sure if you want to lose weight, or just fat. There's a big misconception when people say that want to lose weight. But lifting weight can help you lose fat.