It's a "good" hurt

My roommate and I started training with a trainer this week and boy am I sore! I've worked out with a trainer before, but it's been awhile. My legs and arms have been killing me all week and I love it! I also signed up for the Pat Tillman run in April. It's only 4.2 miles but I am really hoping to run it a decent time. So far so good on my goal of being more healthy this year!