I have been taking lipitor for the last 2 and a half years of 40 ...

I have been taking lipitor for the last 2 and a half years of 40 mg. Since taking the drug, I am having cramps on my legs. First I thought it was more of not drinking enough water but lately it is not the case. I drink more than 8 glasses of water including green tea. LAtely I am having severe cramps with lipitor. The only drug I take and I try to avoid any other drugs for any pains. I am 43 years and run 15 to 20 miles weekly. I am abit worried that it might be Lipitor for the cause. Thank you. nithy