If any of you experience heavy periods, do you find that it affects your training? I get back pain so bad that sometimes I feel like I'm going to pass out. And I tend to believe pretty heavily for about seven days. That's way too long to just skip training all together. But I'm concerned that if I'm running on a heavy day that I might get really woozy and even pass out. Does anyone else to deal with this? If so, how do you handle it?