Leg cramping issue
I'm dealing with some cramping in the backs of my legs that I'm hoping someone can give me some advice on. As a back story, I've been running for about 3 years now, having completed 5 half marathons. I am now training for my first full. At no time in the past have I experienced leg cramps. It actually started as I was finishing up a half back in October. I had just completed mile 12 when suddenly I got a cramp or Charlie horse in my left hamstring. I was able to stretch it out and finish running the half. I was supposed to complete 17 miles that day, but the cramping moved around in the backs of both legs so I had to walk a good portion of it. Fast forward 3 weeks to my 20 mile training run. Felt pretty good durning the run, but again, right after mile 12 I got another cramp. This time in my right calf. I tried working it out, but the cramping again moved up into my hamstrings and my other calf. So I was not able to complete this run. I have always ran in Asics Nimbus and I'm on my second pair this year. Coincidence or not, the half marathon when the cramps started were in my new pair. They are the same model as my previous pair, just a different color.
I stopped into our local running store to talk about it with the owner. He said he'd be surprised if my shoes were causing the cramping, especially considering they are the same model I'd been running in with no issues and the cramps are in different spots. He suggested hydrating really well all week leading up to runs, and especially during runs. He also suggested salt tablets, which I planned to try this weekend. But during my run tonight it seemed like my feet were really tight, especially in the toes. So now I'm wondering if it really is something with the shoes.
I thought I'd put my issue on here hoping it's a common thing that others have dealt with and can offer some suggestions. With my long run coming this weekend, I'm hoping to have something that puts my mind at ease. With a little over a month to go, and 15 miles really being my longest run, I'm really hoping to get this under control.
Thanks in advance for any advice or suggestions!