50-something runner here - have done many half-marathons etc. I always run on paved surfaces, no issues at all.

Here's a thought - maybe check your running form, sometimes less is more. You don't have to be all spring-y with your knees. While you don't want to shuffle, of course, fast little comfortable flicks are just fine - and because you'll have a higher cadance as a result, that can actually make you go faster compared to big bounding steps. If you have an animated gait, especially if you are used to bouncy treadmills, maybe try toning it down a bit on the roads and see if that helps.

I do find the treadmill much easier on my body. And I like it because I get to watch TV!

I've never noticed a difference in outside vs treadmill so it's probably the shoes. Replace those every 400-450 miles, and try to go for softer surfaces than sidewalk. Also, visit a real running store for the shoes, and then after that, you can save some money by looking for sales online. Good luck!

New shoes will probably help. If you are new to running, the muscles in your feet may be adjusting as well.

I'll also add that at 49, I seek out packed dirt or similar paths and trails, and try to minimize running on asphalt or concrete sidewalks.

New shoes and new socks. I'm a runner and I replace my shoes and socks every 500 miles. I absolutely love soft cushiony socks.

Marathon runner here. Def try new shoes. There are great options now. Find one that works and stick with it forever! Just keep replacing (at 3 miles a day you could last for six months on the outside). Have fun and good for you!

Are you running on sidewalks OP? Concrete is brutal. For me, it's golf cart trails or bust.

When you run, you need to replace your shoes often. The sole will get thin fast, especially if you run outside on pavement. Concrete is worse, asphalt is better. Those school tracks with asphalt is softer. Then, there are asphalt like that feels more like rubber. Also, the pavement is so bad for your feet and knees with all the pounding. For me, if you run outside, do trail running or jog. Less pounding. But, if you do trail running, you have to watch out for rocks, erosion, root and plants that stick out. So much to think about right.
Or you can jog up hills, slowly with small steps.

You may need new shoes, but if you're OK on the treadmill, it's probably not the shoes. Where are you running outside? Concrete sidewalk? Asphalt? Try a trail with a soft landing pad?

We talking a traditional super bouncy treadmill? Possibly that’s your issue.

It never hurts to go to a real running store like pacers. They will have have a high quality treadmill like a woodway that will be more like running outside. Life is too short to be running in the wrong shoes.

I'm OK on the treadmill but 3miles outside is making my feet sore. Do I need better shoes or getting used to running outdoors?