So I was talking with my sister yesterday and she may have helped me connect the dots. Recently, since before the marathon, I've started drinking a ton of soda again. Sometimes I would even go through the whole day with no water, only soda (I know, what kind of runner subsists on soda only?), which is a very bad habit. The days leading into the marathon I did this, as well as leading into the half marathon this past weekend.
So my sister mentioned that maybe my muscles are little bit dehydrated because I am not drinking enough water to offset the soda. This got me thinking. I remembered reading an article, either online or in a magazine (if anyone remembers such an article please let me know), that said that a small fluctuation in the amount of water in your muscles can lead to fatigue early on in your run. So I most certainly didn't have the correct "water balance" in my muscles. So would this also mean that low water in the muscles, plus long run, equals very sore muscles?
If so this would explain why my calves were/are sore still from the half marathon on Saturday (when I usually don't get sore) and perhaps also explains why my calves seized up on me during the marathon. Food for thought.
PS Thanks Sis!