Why do my inner knees hurt after I run?

An extra 50lbs will definitely make your knees ache but if it’s moreso in one part of the knee then I’d say it’s to do with your pronation. Have you considered to start off slower by fast walking instead? You’ll still have to be conscious of your foot and ankle form but there will be less counterbounce from the weight to throw you off.
I ran competitively for several years and we’d work on running form and pronation according to body shape before blasting off on a training routine.

I am walking 5 mins before I start running and walk 5 after the run to cool down.

Running is really hard on your knees no matter what. Make sure you warm up and stretch properly—whenever I blow either one off, I end up with knee pain.

Don’t overdo it. Try not to run too fast, too far, or too often—that will aggravate your knee pain and potentially cause more serious injuries.

If overpronation or supination is contributing to your knee pain, you may need to get different shoes. When you bought yours, did you have them professionally fitted in a running store?

Not at all, actually I went by a store and they recommend everything but Nike Shox, and I’ll work on stretching before hand more.

So maybe new shoes are in order. Either way, I think it’s awesome what you’re doing. Good luck :)

@nikipedia thanks

As you get older, your cartilage starts to wear. You should take a break and take supplements to help with joint problems in the knee. Everyone is right about the shoes because arches are important to reduce the impact that travel to your knees. Ice will reduce inflammation.

See your local podiatrist? and Good luck !