Getting old is not for sissies.
I used to play several fast sports: soccer, basketball, and squash, which is much harder than racquetball, until age 50. I could not play to my full potential and started playing double tennis. To my surprise, I was getting injured and pain continuously. By the time I reached 60, I had several surgeries to fix my knees and eventually replaced one knee. I decided not to play anymore, and since then I've felt great. Hardly ever Advil since then.
The answer isn't pickleball; My Ortho loves tennis and pickleball because it made him rich very quickly.
The answer for me has been LA Fitness 3 times per week and doing biking, elliptical, lifting, stretching, balancing and swimming. I also joined an older hiking group, and we hike once per week for 3-4 miles. It's cheap, easy, a great time spending with friends, and the weather in ATL is accommodating. I also walk my dog 2-3 a couple of miles per day. Another exercise is cleaning our big house; it also saves us money
My son noticed that I lost a lot of muscle mass. I started taking protein powder, and within several weeks I started feeling much better and more powerful. Before, I would come home from LA Fitness exhausted. After the protein, just a bit tired, which is normal. He found me a good one on Amazon (
link).
For back pain I found the McKenzie Method about 20 years ago. It's simple, it works, and it's known around the world. You can buy his book, 7 Steps to a Pain-Free Life: How to Rapidly Relieve Back, Neck, and Shoulder Pain (
link). The video below is a very good one too. Basically, you do the Cobra several times per day for 30 seconds each time until the pain is gone and it does within 4-5 days and then you do it when your lower back hurts one time.