Treadmills and death risks, and how to extend life the fast way

Fasting has been shown in mice to extend lifespan and reduce age-related diseases. But for people who don't want to undereat for their whole lives, intermittent fasting may mimic some of the benefits of fasting, say University of Florida Health researchers. In their study in the journal Rejuvenation Research, 24 subjects alternated between one day of eating 25 per cent of their daily caloric intake with one day of eating 175 per cent of their daily caloric intake. That's 650 calories on the fasting days and 4,550 calories on the feasting days for the average male subject. Intermittent fasting caused a slight increase to SIRT 3, a gene that promotes longevity and is involved in protective cell responses. Interestingly, adding antioxidant supplements such as vitamins C and E was found to counteract some of those benefits. "You need some pain, some inflammation, some oxidative stress for some regeneration or repair," says Christiaan Leeuwenburgh, the study's co-author.

Analysing data from 58,000 heart stress tests, Johns Hopkins cardiologists have developed a formula that estimates one's risk of dying over a decade based on a person's ability to exercise on a treadmill at an increasing speed and incline. In addition to age and gender, the new algorithm - dubbed the FIT Treadmill Score - factors in peak heart rate reached during intense exercise and the ability to tolerate physical exertion as measured by metabolic equivalents, a gauge of how much energy the body expends during exercise. The researchers created a chart depicting death risk by age, gender and fitness level. For example, a 45-year-old woman with a fitness score in the bottom fifth percentile is estimated to have a 38 per cent risk of dying over the next decade, compared with 2 per cent for a 45-year-old woman with a top fitness score.