I recently bought two pair of Brooks Trance 7 shoes. (Love them by the way) They were on sale and I paid less than $50 for them. I bought size 13 first - a half size up from my normal running shoe size (12.5) and a half size larger than my normal shoe size (12). I ran in the 13's twice, and they are slightly too big. So, I went back and bought the 12.5's, which are snug, and may be a smidgen too small, but less so than the 13s. Anyway, I took both pair of shoes (I run on the treadmill in both), along with my week's worth of running clothes, to the office. Then, to the gym. Except when I got to the gym tonight I had two left shoes, but alas not two left feet. I had brought the left shoe from both the 12.5 and 13. Uh-oh. No running today, and nothing I could do about it. Rather than just go home, I put the left 13 on my right foot and decided to lift weights only. Upper body, no legs (didn't want to push on the unstable shoes). I hate lifting. I always have - in junior high, high school and now. But I know it is very helpful. Last time I was in serious marathon shape I said that my biggest weakness wasn't my cardio or legs - it was a lack of upper body and core strength. And that next time I ran a marathon, I'd be stronger. And I'd lift more - even at the expense of running and cardio. Actually, it helps prevent over training my legs really. I decided I'd lift 10 minutes for every 30 I ran. Thus, an hour run would mean that I lift weights for 20 minutes. I thought that, on average, I'd end up running 45 minutes, lift weights for 15. Hasn't worked out that way yet, but I have lifted more. Can't say I see any difference yet. But I know I will be thankful come November for all of these bench presses, rows and cables. So I was all excited to run 5 miles at 8:00 pace only to have to slug through a 45 minute lift session instead. I am so beat that it is hard to type.