The Latest Science on Pacing
A new study published in Scientific Reports in early July 2026 has added a fascinating layer to the age-old debate on marathon pacing. After analyzing data from nearly 900,000 Berlin Marathon finishers, researchers found that men are twice as likely as women
to “hit the wall,” which they defined as slowing down by 20% or more in the second half. For runners finishing under three hours, men were a staggering six times more likely to experience this dramatic slowdown. The study suggests that women tend to maintain a more even pace, while men often start too aggressively and pay the price later. The authors propose that men could reduce this risk by adopting a more conservative start, a strategy widely known as a negative split.
The Negative Split Advantage
The idea of a negative split—running the second half of the race faster than the first—is considered the gold standard by many coaches. The primary benefit is energy conservation. By starting at a controlled, slightly slower pace, you primarily use fat for fuel, preserving precious glycogen stores for the difficult final kilometres. Going out too fast, fueled by adrenaline and fresh legs, burns through that glycogen far too early, leading to the dreaded wall. This new research reinforces the idea that a positive split, where you slow down significantly, is often a result of poor initial pacing rather than a viable strategy.
Why One Study Is Never the Whole Story
While this large-scale study offers valuable insights, it's crucial to view it with perspective. First, the findings are based on one marathon course—the flat and fast Berlin Marathon. Pacing strategies must adapt to different terrains; what works in Berlin might not work on the hills of Boston. Furthermore, scientific studies, even large ones, control for some variables but can't account for everything. They don't know if you slept poorly, if the weather was unexpectedly hot, or if your nutrition plan failed mid-race. Research provides averages and trends, but you are an individual, not a statistic.
The 'N of 1' Experiment: You
In training, the most important experiment is the one with a sample size of one: you. Your unique physiology, including your VO2 max, running economy, and lactate threshold, dictates your performance potential. But beyond lab metrics, your training history, mental resilience, and ability to listen to your body are what truly matter on race day. Pacing is a skill developed over hundreds of kilometres in training. It's about learning the difference between a sustainable effort and a risky gamble. Practicing your goal pace during long runs, especially when you're already tired, teaches your body and mind what to expect.
Building Your Personal Pacing Plan
So, how do you blend science with personal experience? Use the research as a starting point. The evidence strongly suggests that starting conservatively is the smartest play for most runners. Consider a strategy like the 10-10-10 method: run the first 10 miles slightly slower than your goal pace, settle into your goal pace for the next 10, and then, if you feel strong, push through the final 10K. But be prepared to adapt. Use a GPS watch for feedback, but don't be a slave to it. Pay more attention to your perceived effort, especially on hills or in windy conditions. Your breath, your legs, and your gut are your most important data sources.
