What are some good low-knee-impact leg-strengthening exercises?

I was recently hospitalized and then bedridden for a period of a couple of months. This caused my leg muscles to deteriorate to the point where doing much more than going to the store wears me out in short order. I am not used to this state of affairs – I’m used to having legs like tree trunks, from back in the day when I was 50 pounds overweight.

I used to run and do squats and leg presses and all of that, but the cartilege in my knees has given up the ghost in the past few years (I was diagnosed at 23 with what they called patellofemoral syndrome), and doing that stuff would hurt more than it would help. While I’m diligent in pushups and situps and all that, I’m not exactly a fitness buff, so I don’t know what other exercises I can do, or machines I can use, etc. in order to get my leg strength back up without destroying my knees.

I know exercise enthusiasts love to share, so I’d love to hear some ideas for things I can do. Thanks!

I’d recommend running these suggestions past someone who actually have medical training/knowledge relevant to your situation, but off the top of my head how about bicycling and swimming? (Swimming is usually a good thing overall)

I had a knee injury long ago and part of the rehab involved bicycles, swimming, cross country skiing in winter (I already owned a pair of skis), and lots of just plain walking. However, my situation was different than yours and I don’t know how much of what I did would work or be recommended for you.

Thanks for the suggestions! I could get my bike out of mothballs, now that I think about it. There are plenty of flat-ish sections of the local riverwalk where I could ride. When I was a teenager I used to bike everywhere, and I don’t remember my knees hurting after a full day’s trek, so that’s probably good.

I also like to swim, despite the fact that my skill level is basically “does not drown.” (I got myself into trouble once – I swim juuuust well enough that my brain isn’t scared of still water, so at a 4th of July party where everyone was jumping off the dock, I leaped right in despite the fact that I hadn’t been swimming in years. I got underwater and had to take a second to remember what to do and how to figure out which way was up.)

I did of course ask my doctor, but, per my usual experience with doctors, he recommended running and squats. I know I lack the requisite expensive paper to definitely declare that a bad idea, but I did it anyway, thus the request for suggestions from the hoi polloi.

One of the more depressing things about COVID era was the closing of gyms. Without access to weights, I felt like I would lose much of my muscle mass. Running Coach sent me an online routine that has saved me: The PERFECT Home Workout (Sets and Reps Included) - YouTube

Sure, nothing can replace weights, but I’ve added hand weights to the leg portions of this regimen. The gyms near me have been closed for almost 4 months now and it at least allows me to maintain. I’ve also found them to be very easy on the knees.

If you have the cash and the space, a good exercise bike will allow you to work your knees and legs as hard or as easy as you want. Put it in front of a TV or grab a Kindle and the hours will fly by.

This is me, but I bought my exercise bike a few years back used from Goodwill for @ $50. It isn’t great, but for a 20-30 minute ride every morning, it works. Especially here in Colorado, where the weather gives you plenty of excuses to skip a ride. I’m normally reading my Kindle, with music playing from my Echo Dot. So I’ve sold myself to the Amazon Ecosystem, but it’s cheaper than Apple’s!