If My Wings Should Fail Me, Lord

How Old are Your Telomeres?

Recently, scientists in Germany gathered several groups of men and women to look at their cells’ life spans. Some of them were young and sedentary, others middle-aged and sedentary. Two other groups were, to put it mildly, active. The first of these consisted of professional runners in their 20s, most of them on the national track-and-field team, training about 45 miles per week. The last were serious, middle-aged longtime runners, with an average age of 51 and a typical training regimen of 50 miles per week, putting those young 45-mile-per-week sluggards to shame.