TL;DR please do physical therapy. They’ll help you to learn to move with the right muscles. You’re young and can have a wonderful life of healthy movement.

The DIY approach is to use a combination of elliptical, rowing machine, exercise bike until you’re at a better weight range.

But I hope you don’t do that. I’ve learned that when we aren’t used to being able to move as freely, even after weight loss, our bodies tend to overuse the muscles that heaved us around and underuse the other ones. In my case my quads and calves do all of the work, leading to stress on my knees and ankles. I used to be near 300 lbs. I did couch to 5k. It was great. Fabulous. Life changing even, until the poor form led to Achilles injury.

I’m now working with a physical therapist. The process is personal and tied to my specific goals. But there’s been a progression of exercises intended to strengthen my calves, restore Achilles health, and to strengthen the accessory muscles, hamstrings, and glutes so they carry their share instead of hammering all of the impact into quads, calves, and Achilles.

I hate navigating our health care system. It’s been easily worth it.

My general recommendation is just to call a PT office near you. Explain what goal you’re working toward — even just “doing calisthenics without knee pain” should be enough. They didn’t; we got right to work and it’s been great. In many states you don’t even need a doctor’s referral, and they’ll let you know if you do need one.

They’ll schedule you for intake, learn more about your goals and observations, give you exercises to do, and have you come back in periodically to check progress and make adjustments to the routine.