In the Tour de France, everyone knows the power of the peloton: The riders in a pack almost always outpace loners. Even though slower speeds in running races mean drafting's benefits are smaller, tucking in can make holding a pace easier, mentally and physically.
But not just any pack will do. Earlier this year, researcher Brian Hanley published an analysis of the pack-running behavior of competitors at the IAAF World Half Marathon Championships between 2007 and 2014. By studying how packs formed and splintered, he was able to determine which strategies worked best—and which backfired.
All About 75 Hard
The most successful runners—those who best maintained their pace throughout the race and sped up the most at the finish—were those who ran with the same group from start to finish. Sometimes the packs consisted of teammates, but often it was rivals of similar ability. These days, many big races set up pace groups aiming for predetermined goal times; you can also set up your own pack via message boards or social media, or simply look for kindred souls during the early miles of a race. It's fine to tuck behind someone for a few miles, but after that, it's your turn to lead.
Health & Injuries
The next-best outcomes came from those who ran most of the race with other runners—but not always the same ones. If you realize that you're stronger than the other runners in your pack, look up the road to see if there's another group you could join. Then, make a decisive move to catch them instead of lingering in no-man's-land. Conversely, if you're getting dropped by your pack, it's very easy to become disheartened. Instead, slow a little, regroup, and prepare mentally to latch onto the next pack that comes up behind you.
Worst: Starter Packs
The worst strategy of all—worse even than running the whole race alone—is to try to stick with a pack that's too fast for you. In Hanley's analysis, those who started with a pack but were dropped before reaching the halfway point of the race slowed down the most as the race progressed. Setting realistic goals will help you avoid this trap, but sometimes the energy of a pack is so contagious that the whole group goes faster than intended—desire in the 2013 London Marathon, when a 1:01:34 first half wreaked havoc on the entire lead pack. Check your splits periodically to make sure your pack-mates aren't getting carried away.
Best: Persistent Packs
Once you've found the right pack, tuck in. The best position aerodynamically is directly behind someone else, within about three feet. (Don't clip the leader's heels.) Top marathoners burn about two percent of their energy overcoming air resistance even on a calm day, and more on windy days, so positioning does matter. But packs are most effective when everyone shares the pacemaking duties. Think of the other runners in the pack as your teammates, and work together—until the final mile, when all treaties dissolve.
