There is a dirty little secret known to health professionals that they do not usually much talk about. Let's assume that you follow the recommendations of a health authority and get out there most days to go jogging, even though you would much rather be doing something else. Say you get ready, warm up, jog, and cool down for about an hour a day, which is a modest regimen.

Over a year, you will spend about 360 hours doing this, and during 40 years (say, from age twenty-one to age sixty-one), you will spend about $\fbox{ア}$ hours. Assuming that most of us are awake for about 16 hours a day, this means that you would be spending the equivalent of about $\fbox{イ}$days jogging. This is about two and a half years spent exercising.

How much longer would such an active person live? How many extra days of life would this diligent jogger gain in which to pursue other well-loved hobbies? We do not know for sure, but anything that increased average longevity by more than two and a half years in a generally healthy adult population would be considered a very large effect－a striking phenomenon. So, with two and a half years spent on the pavement, there is not likely to be much of a net gain in available time for our poor jogger. Anyone who exercised even more would gain even less, winding up with a net loss of　time. But it gets even worse. Note that in this contrived example, the unhappy jogger is trading away thousands of hours of youth for perhaps a few extra years in old age (ウ)Many individuals would not choose that trade-off. They would prefer to have their leisure time when they are young and healthy.

Of course the real picture is somewhat more complicated. The jogger might really enjoy jogging and so might consider the time well spent. Or the jogger might be warding off a diagnosed tendency toward a debilitating chronic disease such as diabetes. Still, for many reasonably healthy and active individuals who are out running every morning because some advice list or some friend is pressuring them to try to improve their health, the results are not necessarily going to be what they expect (エ)Some might have better uses for all that time, and others will be harmed by running injuries or even sudden death from cardiac arrest.

From a public health point of view, it's great that so many people these days like to engage in socially hyped challenges like marathons. But it is important to recognize that these are recent social phenomena, and that many people in the past remained steadily active in a healthy way having never even heard of a jogging trail or a spinning class.

• 1.空欄$\fbox{ア}$、$\fbox{イ}$に入る数字を記入しなさい。
• 2.下線部(ウ)にあるthat trade-off の内容を明らかにして日本語に訳しなさい。
• 3.下線部(エ)を日本語に訳しなさい。