Blood flows in veins due to contractions of surrounding muscle. When you're sitting, your lower body is largely relaxed, which causes blood to pool in your lowe

Blood flows in veins due to contractions of surrounding muscle. When you're sitting, your lower body is largely relaxed, which causes blood to pool in your lower body. It's a serious (acute) issue in people who are bedridden for long periods of time. I suppose the article is suggesting there's a downside to chronic, low grade exposure as well.