At the high school track today I watched young runners doing skip-and-swing warm-up drills. For a moment I thought I was back in the 1950s. Then I remembered. They were doing "dynamic stretching," the latest scientifically approved prerequisite for an effective training session.

Things change, and happily that can include the things you were supposed to do but didn't enjoy. Like static stretching. In my elite days in the 1980s, every runner before a race was propped at a 45-degree angle against a tree or wall or someone else's car. "Trying to push it over?" the passing public would inquire jovially, as you leaned, one calf extended back behind, pressing, creaking, silently counting. "No stretch less than 45 seconds is effective," was the mantra. The stretch had to be lo-oo-oo-ng. Impatient to race, I thought about Robert Redford as the Sundance Kid drawing his six-gun, when he pleaded, "Can I move now?"

And sure enough, movement is back. Coaching best practice has dumped those long static stretches, and brought in (or back) "dynamic drills" — skips, leg swings, lunge twists, butt kicks, reach-for-the-sky extensions. My ex-Army high school physical education teacher had us doing those half a century ago. Things come around. But not everything.