Risk of venous thrombosis and other vascular conditions is known to increase in those who sit excessively. Howard et al. at the Baker IDI Heart and Diabetes Institute in Melbourne, Australia performed a study to determine if interrupting excessive sitting with intermittent physical activity can reduce the risk of developing a clot in sedentary, middle-age, overweight to obese adults. Uninterrupted sitting resulted in unfavorable changes of key blood viscosity parameters including increased fibrinogen, hematocrit, and hemoglobin. These effects were significantly ameliorated by both light and moderate intensity breaks between sitting, indicating reduced hemostasis and risk of clot formation. The authors concluded that in an acute setting, "...blood viscosity may contribute to the well-documented increased risk of thrombosis associated with excessive sitting."