The art and science of pacing, why “coachability” matters, and more

The latest research on endurance, fitness, health, and adventure.

How the heck are runners running so fast these days? Like a good murder mystery, there are plenty of legitimate suspects: supershoes, baking soda, carbohydrates, money, drugs… and pacing. In Eliud Kipchoge’s Breaking2 marathon back in 2017, his half-dozen pacemakers were mostly thought to be breaking the wind for him. But in 2018, World Athletics approved Wavelight pacing lights for track races, which help dial in an even pace with or without a human pacemaker.

A new paper in the International Journal of Sports Physiology and Performance makes the case that pacing lights really are helping runners go faster. A team led by Pablo Comino of Spain’s Rey Juan Carlos University analyzed 45 Diamond League 1,500-metre races between 2021 and 2024, of which 33 featured pacing lights and 12 didn’t. The overall conclusion is that the Wavelight races were faster (by about four seconds, for those in the top half of the field)—and, crucially, paced more evenly, with fewer position changes.

Here’s one of the key graphs, showing average pace for runners finishing in the top four of each race:

The key moment comes at the end of the first lap, after the initial jostling for position has settled down. This is where the runners tend to settle into a slower, more sustainable pace. But the pacing lights remind them not to settle too much, spurring them to maintain a slightly quicker tempo. In the final lap of the race, the unpaced runners are able to speed up more, but not enough to make up the time they lost in the middle section of the race.

There’s another interesting visual, showing the average intermediate placings of each of the top 12 finishers for both types of race. Check out how much passing and disruption there is in the non-Wavelight races, while in the Wavelight races the runners mostly seem to tuck in along the rail and stay in one position:

There are some important limitations to this analysis. Most notably, it may be that athletes were more likely to chase fast times in Wavelight races, and to focus on placing on non-Wavelight races. Comino’s paper includes a list of no less than 26 world records set with pacing lights between August 2020 and May 2025. That’s hugely impressive, but it’s hard to imagine that any of those runners would even have attempted a record at a meet with no Wavelight.

Still, the links between pacing lights, more even pacing, fewer position changes, and faster times is pretty compelling—and the message is relevant even to those of us who may never encounter pacing lights. To me, the benefits of tucking behind another runner have always seemed bigger than drafting alone: pacing yourself correctly requires a lot of mental effort, and I’d rather save that effort for the latter stages of the race.

Was that TLDR?

You can also check out my two-minute video summary of that Wavelight study. I’ve been playing around lately with super-short videos on Instagram about key studies or insights. Some of the other topics I’ve discussed are what to think about when you run, running cadence, and the difference between how hot you feel and how hot you really are. Let me know what you think in the comments!

Meanwhile at Outside…

My latest Sweat Science columns tackle:

• the six dimensions of “coachability” and why they matter for your performance even if you don’t have a coach;

• why 7 out of 10 might be the effort sweet spot (in at least some contexts) for interval workouts;

• how sitting less can improve mitochondrial health and metabolic flexibility;

• the potential benefits of baking soda for enhancing performance at altitude.

On the podcast circuit, I had a super interesting conversation with Eric Zimmer on The One You Feed about personal exploration (drawing on my recent book The Explorer’s Gene, which I hope you’ll check out!), and earlier this year I chatted with Ross Tucker and Mike Finch about the challenges of science/health/sports journalism on The Real Science of Sport Podcast.

Thanks for reading!

Alex Hutchinson