Armed with better tools, such as lightweight accelerometers, and given much more data to work with, epidemiologists are nowadays trying to quantify the degree to which specific forms of exercise are better or worse then others. Other teams are trying to put rigorous numbers to the dose-response curve for exercise: where is the optimal point when it comes to health and longevity? It is a given that regular moderate aerobic exercise is good for you, and the evidence for that is overwhelming. Sedentary people suffer shorter lives and a greater burden of age-related disease. But once we start to ask how much exercise is most advantageous, or whether one form of exercise is better than another, then the answers become much less certain. They depend far more upon interpretations of data and the limitations of specific data sets, the details of which can be quite complex - and will thus never appear in the popular press when specific research projects are discussed.

The only useful way to look at this sort of research is in aggregate, summed over many studies. At this point there are simply too few papers comparing different forms of exercise to say more than that it is an interesting topic: I would say that many more years of work are needed to assemble a good consensus for human data, and even then that consensus will be fuzzy around the edges, numbers subject to opinion on various scientific factions and their methodologies. Thus attempting to optimize lifestyle for health and longevity strikes me as a pleasant hobby to maintain, but no matter how much effort you put into it, you'll likely never find out whether you are in fact doing any better than the 80/20 level achieved with far less work.

Given that the future of our health will be increasingly determined by progress in medicine as we age, I would argue that we should direct our extra time and effort towards supporting research into therapies to treat the causes of aging, as opposed to chasing the mirage of a perfectly optimal lifestyle. Good enough is comparatively easy to achieve when it comes to personal health, while significantly more than that is a next to impossible goal. Meanwhile, absent new technologies based on the SENS rejuvenation research programs, even the healthiest of us in mid-life today have but a small chance of making it to 100, and we'll be very frail indeed should we manage to hold out to that point. Technology should be the focus.

An Hour of Running May Add 7 Hours to Your Life

Resarchers found that, compared to nonrunners, runners tended to live about three additional years, even if they run slowly or sporadically and smoke, drink or are overweight. No other form of exercise that researchers looked at showed comparable impacts on life span. The findings come as a follow-up to a study done three years ago, in which a group of distinguished exercise scientists scrutinized data from a large trove of medical and fitness tests. That analysis found that as little as five minutes of daily running was associated with prolonged life spans. Over all, this new review reinforced the findings of the earlier research, the scientists determined. Cumulatively, the data indicated that running, whatever someone's pace or mileage, dropped a person's risk of premature death by almost 40 percent, a benefit that held true even when the researchers controlled for smoking, drinking and a history of health problems such as hypertension or obesity. Perhaps most interesting, the researchers calculated that, hour for hour, running statistically returns more time to people's lives than it consumes. Figuring two hours per week of training, since that was the average reported by runners in the earlier study, the researchers estimated that a typical runner would spend less than six months actually running over the course of almost 40 years, but could expect an increase in life expectancy of 3.2 years, for a net gain of about 2.8 years. In concrete terms, an hour of running statistically lengthens life expectancy by seven hours, the researchers report. The gains in life expectancy are capped at around three extra years, however much people run. The good news is that prolonged running does not seem to become counterproductive for longevity, according to the data. Improvements in life expectancy generally plateaued at about four hours of running per week, but they did not decline. Meanwhile, other kinds of exercise also reliably benefited life expectancy, the researchers found, but not to the same degree as running. Walking, cycling and other activities, even if they required the same exertion as running, typically dropped the risk of premature death by about 12 percent. Why running should be so uniquely potent against early mortality remains uncertain, but it raises aerobic fitness, and high aerobic fitness is one of the best-known indicators of an individual's long-term health.

Running as a Key Lifestyle Medicine for Longevity