Got this from Boing Boing via the great Russell Barth:
In 2002, over 2000 people between the ages of 51 and 80 were asked to sit on the floor using as little hand- or knee-support as possible. They were then asked to stand up without resorting to using their hands or knees if they were able. The results were recorded. By the end of October 2011, 159 subjects had died. It turns out that most of the people who died were the ones who needed the most support while performing the task. Only 2 of the 159 people who died had been able to sit down and stand up unsupported: "These differences persisted when results were controlled for age, gender and body mass index, suggesting that the sitting-rising test score is a significant predictor of all-cause mortality."
Damn right you are going to try it right now.