I just found out last week that I have Osgood-Schlatter Disease which causes knee pain. Exercising with a sore knee is no fun. If yours hurts after running put an ice pack on it right away. It will keep the swelling and the pain down.

Don't overdo it though. Cardio is best when you do not reach your maximum pulse. It's more important do be regular than to exercise hard. After all, you are supposed to be doing that regularly for the rest of your life.

P.S. Thanks for your comments on my blog

Wow, that's awesome!

First of all, congrats on your running! I think it's great that you're really getting into it. Trust me, as someone who has gone from not being able to run 1/2 a mile to training for my third marathon this December, I swear it gets easier and more fun.

However, a quick word of advice: as you're just starting out again, I suggest you not run every day. Your body isn't used to it at this point and you're risking injury or burnout. It's probably why you were so sluggish on this run. My suggestion is to run every other day, so you have a chance to recover in between. If you want to exercise every day, do something else between running: bodyweight exercises, cycling, swimming, soccer, etc.

But keep at it! Don't push yourself too hard, take baby steps, and most of all, enjoy yourself!

Thanks Leo. Yeah, that is what I normally set out to do (don't usually make it!) but I'm just trying something new this week to shake things up.