Secret Importance of the Negative Split in Running You Never Knew

Importance of the Negative Split
The vast majority of long distance runners finish the first half of the race faster than they finish the second half. This method of slowing down during the second half is called a positive split, and should be avoided, despite how common it is. The better way to run a race is with a negative split, and this article explains why.
SportsAspire Staff
Last Updated: May 31, 2018
Professional distance runners spend a great deal of energy trying to determine the best strategies for running races of various distances. Between studying exercise science, working with coaches and trainers, and engaging in trial and error in their own personal training schedule, these runners can shave seconds off their already unbelievably fast race times in order to rise to the top of the ranks within professional running. For most of us, that level of dedication and in-depth knowledge isn't necessary to have rewarding careers as hobbyists who run for fun and fitness. Sometimes though, exercise science can teach us a thing or two about how to run at our best.
What is a Negative Split?
One of the most often overlooked strategies for performing well in distance races is the concept of the negative split. In running parlance, a split is a point somewhere in the middle of the race when a runner's time is recorded. Split times are important because they allow distance runners to see whether they have been running at a consistent pace, and to adjust their speed accordingly. Split times can be recorded every mile or just once in the middle of the race. For marathon runners, 'the split' is that point exactly in the middle of the race, and the split time is how fast a runner ran the first half of the marathon. A negative split, then, is a situation where a runner runs the second half of the race faster than she or he ran the first half.
How Common is the Negative Split?
Statistics indicate that, in large marathons, only around 10% of runners finish with a negative split. The other 90% run the first half of the race faster, slowing down for the second half. According to exercise scientists and professional running theory, this is the wrong way to run a race.
Conserve Energy in the First Half
Perhaps the most obvious benefit of running with a negative split is that you conserve energy during the first half of the race. If you run slightly slower over the first half of the course, you will feel less exhausted and fatigued as you begin the second half. This allows you to use your energy efficiently and perform to the best of your ability over the course of the whole race. So, by running a negative split, you slow down the first half in order to improve your overall time.
Boost Confidence by Running Faster
According to the editors of Runner's World magazine, another important benefit of the negative split is a psychological benefit. The last few miles of a marathon may be the most difficult to run, because psychologically, runners feel tired, sluggish, and like they can't go on. Overcoming this psychological obstacle can be difficult, and an inability to maintain excitement and confidence during the last half of the race could prevent you achieving your best possible time. If you plan for a negative split, though, you can help yourself out psychologically. By speeding up during the second half of the race, you will notice that you begin to pass other runners who have slowed down after running too fast during the first half. Passing so many others will help you feel good about your performance, and this confidence could give you the energy boost you need to run even faster.
How to Plan for a Negative Split?
In order to plan for a negative split, calculate your target pace, and for the first one-third to one-half of the race, run just slightly slower than that pace. Then, around the midway point, speed up to your target pace and maintain it for several miles. When you come to the final few miles in the race, speed up until you are running slightly faster than your target pace, and maintain this top speed all the way to the finish line. You can practice training your body to run faster when it gets tired by incorporating regular tempo runs into your training schedule. Run slow at first, gradually speeding up to a comfortable but challenging pace. This way, you'll be able to endure running at faster paces even though you have already been running for some time. When you've trained right, you'll be able to achieve the elusive negative split, bringing your running one step closer to a professional level.