In almost every racing scenario, negative splits are the ideal pacing strategy.
A negative split is when the second half of a race is faster than the first half. For example, if you race a 10K with 5K splits of 25:30 and 24:30 for a 50:00 finish time, you’ve just ran a negative split—your second split time is less than your first.
It may seem more difficult to run negative splits on race day, but in fact it can be easier and is often the route to your best performance. It takes 1-2 miles to properly warm up during a race. By then, your joints are fully lubricated, adrenaline and other performance-boosting hormones are peaking, and muscles are primed to work at their most efficient capacity.
In short, you’re not ready to run at your best until the middle of the race—making a negative split easier to attain, and more effective, than most think.
When the opposite happens—you positive split the race, running the first half faster than the second—you’re not allowing the body to be properly warmed up nor taking advantage of the hormones that make racing fast a bit easier. Every runner has had the experience of starting a race fast only to flounder and pull up short in the later miles. Going hard and slowly dying is also far tougher psychologically than still running strong in the later miles while others are flailing and falling away.
Want proof? Look at runners at the highest levels of our sport.
Negative Splits and World Records
Most world records above 800m have been set with negative splits. Recent marathon history shows this strategy used effectively to consistently lower the world record.
In 2007, Haile Gebrselassie set the marathon world record of 2:04:26 with a spread of 62:29 and 61:57. The next year, when he broke 2:04, his half marathon splits were 62:05 and 61:54.
When Dennis Kimetto lowered the marathon world record to 2:02:57 in 2014 at the Berlin Marathon, he ran the first half in 61:45 and the second half in 61:12.
In 2018, when Eliud Kipchoge took that world record down to 2:01:39, he split 61:06/ 60:33. Kipchoge also ran his second half roughly 10 seconds faster than his first when he ran 1:59:40 at the INEOS 1:59 Challenge last October.
U.S. Olympic marathoner Jared Ward has built a reputation for executing precisely paced races—he even he wrote his Master’s thesis in the field of statistics on optimal pacing strategies for the marathon. That methodical approach paid off at the Rio Olympics when Ward earned a surprising 6th place finish, owing in part to an extremely strong final 10K where he passed many runners who had faded.
This strategy extends beyond the marathon, however. When Kenenisa Bekele ran the 10,000m world record of 26:17:53, his 5K splits were 13:09:19 and 13:08:34. When he set the 5,000m world record of 12:37.35, his 1km splits were 2:33.2, 2:32.2, 2:31.8, 2:30.5, and 2:29.4—the last his fastest.
Galen Rupp had a fantastic negative split performance when he set the American record in the indoor 5K of 13:01.26. His mile splits were 4:14, 4:12, and 4:04 with a final 200m split of 30.36.
It’s clear that the limits of human potential are set with a negative split strategy. Top coaches also believe negative splits are ideal for recreational runners—if you learn how to execute them effectively.
How to Negative Split Your Next Race
While it’s easy to say “finish faster than you started,” it’s much more difficult to put into practice. That’s why it’s critical to practice negative splits during training to ensure you’re used to the feeling and execution of this strategy on race day.
Training tip #1: Negative split easy runs
Easy runs should be negative splits all the time, even if you’re not practicing the strategy. Start slow to help you transition to running and allow your body to warm up properly. After a few miles, you can settle into your “normal” pace.
If you’re a more advanced runner or are just feeling great, you can run the last 1-2 miles of your easy runs at a moderate effort. This will surely guarantee a negative-split run, helping your body and mind remember what it’s like to finish a run faster than when you started.
Training tip #2: Negative split workouts
The absolute best way to practice negative splits is to run them during a structured workout.
Negative splits work best in single-speed workouts where you run the same speed for the entirety of the repetitions; for example, 6 x 800m at 5K pace. To negative split, run the last two slightly faster. Be sure, however, not to turn the workout into a race and still run within your means.
This strategy forces you to run harder when you’re fatigued—exactly what’s needed during a race to finish with negative splits. Finishing later reps strongly will build your confidence in the effectiveness of the strategy and your ability to execute it.
Racing tip #1: Predict an accurate finish time
A negative split is virtually impossible if you don’t have an accurate finish time prediction. After all, if you think you can run faster than you’re able to and start too fast, you’ll fizzle out rather than speeding up.
For example, if you’d like to negative split a 10K and you’re confident you can run 50:00, aim to run the first 5K in about 25:10-25:30. That should be comfortable enough that you can turn on the afterburners in the last 2 miles to finish in 50 flat or faster.
Your recent workouts can help predict what can do on race day, and you’ll get better at judging effort during every mile as you gain race experience. If in doubt, whether setting a goal pace or judging effort, be slightly conservative. Trust that you will be able to close faster if the pace ends up easier than you expect. Very rarely do runners end up with a huge negative split and regret a too-slow pace early on.
Racing tip #2: Be confident
Negative splits can be challenging—there’s no way around it. But when top coaches recommend them and world records are set using this race pacing strategy, you know it’s the real deal.
But it can only be achieved if you’re confident in your abilities. Initially you have to have the confidence to go slower early in the race, trusting that you can sustain your energy and increase the pace during later miles. When those later miles come, running fast when you’re tired hurts. You’re in “the pain cave,” taking a bath in lactate. Your brain is screaming at you to slow down.
The only way to finish strong is to believe in your fitness. That confidence—and a good dose of mental toughness—will help you maintain focus, keep the effort on the red-line, and increase your pace. As you continue to click off fast miles, your confidence will grow, carrying you across the finish line with negative splits—and hopefully, a shiny new PR!