So just as longevity might be improving at a fast clip were it not for expanding waistlines, death rates in traffic accidents might show a more positive trend were it not for the SUV explosion.
所以正如如果没有不断增长的腰围,人们的寿命可能会迅速增加一样，如果没有 SUV数量的激增，交通事故中的死亡率也许会呈现一个更加良好的趋势。
The proliferation of cars also encourages us to drive rather than walk. A century ago, the typical American walked three miles a day; now the average is less than a quarter mile a day. Some research suggests that the sedentary lifestyle, rather than weight itself, is the real threat; a chubby person who is physically active will be OK. Studies also show that it is not necessary to do aerobics to get the benefits of exercise; a half-hour a day of brisk walking is sufficient. But more cars, driven more miles, mean less walking.
汽车的激增也促使我们开车而不走路。一个世纪前，一般情况下，美国人每天走3英里，而现在每天平均不到0.25英里。一些研究表明，真正的威胁是久坐不动的生活方式，而不是体重本身；一个爱运动的胖乎乎的牧师是没有问题的。研究还表明，通过做有氧运动来获得运动的好处是没有必要的，每天半小时的快走就足够了。然而，更多的车，行驶更多英里的路，则意味着步行的减少。