The Old Rules of Pacing
For as long as runners have chased personal bests, they have been told to master their pacing. The two dominant philosophies have always been the even split and the negative split. The even split strategy involves maintaining a consistent pace from start
to finish, which is mathematically the fastest way to cover a distance on a flat course. The negative split, where the second half of the race is run faster than the first, is often considered the holy grail of marathon execution. Proponents argue that a conservative start saves precious glycogen stores, allowing for a strong finish where you pass flagging runners instead of becoming one. The one strategy everyone agrees to avoid is the positive split—starting too fast and slowing down significantly. This is seen not as a strategy, but as a mistake, the classic recipe for hitting the dreaded 'wall'.
A Surprising New Finding
A major new study published in Scientific Reports has shifted the focus from the 'what' of pacing to the 'who'. Researchers analyzed data from over 870,000 finishers of the Berlin Marathon between 1999 and 2025. They defined 'hitting the wall' as slowing down by 20% or more in the second half compared to the first. The results were stark: men were nearly twice as likely as women to experience this catastrophic slowdown. The gap was even more dramatic among faster runners; men finishing under three hours were about six times more likely than women in the same performance bracket to hit the wall. While men were faster on average, women demonstrated a superior ability to maintain a consistent pace throughout the entire 42.2-kilometre distance.
Why the Pacing Gap?
The study suggests the difference isn't just physiological, but behavioural. Researchers pointed to factors like overconfidence and greater risk-taking among male runners, who may be more prone to starting too aggressively and paying the price later. In contrast, the data showed women exhibited more stable and efficient pacing strategies, suggesting a better innate sense of self-pacing and greater resistance to decision-making fatigue during the race. While men possess certain physiological advantages like greater muscle mass and higher hemoglobin concentrations, women appear to be behaviourally more efficient. This aligns with previous research which also found women were better at running an even pace, especially among faster and more experienced runners. The new research solidifies the idea that pacing is the most critical tactical element of a marathon, where managing energy is just as important as raw speed.
From Science to Race Strategy
This research changes the planning conversation by moving it from a generic ideal to a personalised risk assessment. The key takeaway isn't that one gender is a better runner, but that a significant portion of runners, particularly men, are sabotaging their own races by being too aggressive early on. The lesson is universal: an optimistic start often leads to a pessimistic finish. This reinforces what we know about glycogen depletion. Starting just a few seconds per kilometre too fast shifts your body into a higher-intensity zone, burning through your limited carbohydrate stores much earlier than planned. By the time you reach the 30-kilometre mark, the deficit is irreversible. The new findings serve as a large-scale, data-backed warning against the dangers of race-day adrenaline and overconfidence.
Redefining Your Marathon Plan
So how do you apply this? The first step is honest self-assessment. Regardless of gender, are you someone who gets swept up in the excitement and goes out too fast? If so, your entire race plan needs to be built around discipline in the first 10 kilometres. Make your goal to feel like you're holding back, even if it feels too slow. Trust the plan, not the feeling. Your training should support this. Other research suggests that consistency is more important than intensity; running more frequently with most runs at an easy pace builds a stronger aerobic base. Hard, race-pace workouts have their place, but over-emphasizing them can actually lead to slower finish times. For your next marathon, build a plan that prioritises a conservative first half. You can still aim for a negative split, but the primary goal should be to avoid a positive split at all costs. Think of the first half not as building a time cushion, but as conserving the energy you'll desperately need for a strong final 10 kilometres.
