As the high school track and spring racing seasons heat up, there is one sure-fire way to help your racing: don’t start too quickly. Save something back at the start and you will learn about the joys of negative splits –– running the last half of your race more quickly than the first.
The wisdom of running negative splits holds for every distance longer than 800 meters. According to Jeff Gaudett, in Learn to Pace Like a Pro, “Every current world record, from the 1500 meters to the marathon, has been set by an athlete running negative splits.” (http://www.runnersworld.com/racing/learn-to-pace-like-a-pro)
At first glance, running negative splits does seem to be counterintuitive. Shouldn’t you try to “bank” time while you’re fresh and before your form breaks down and your efficiency declines? In fact, banking time at the beginning of a race while you are fresh and feeling good seldom works. It is always better to save something for the end.
Here’s the science behind negative splits: The faster you run at the beginning of your race, the greater the percentage of your energy will come from carbohydrates. When you start faster than your goal pace and try to put “time in the bank,” you exhaust your carbohydrate stores prematurely. Ideally, you should run slightly slower than your lactate threshold pace for as long as possible. This will make your body draw on your fat stores for fuel, leaving carbohydrates in the tank to fuel you later when the racing really starts. Thus, to achieve negative splits, begin ten to twenty seconds slower per mile than your goal race pace.
But what is your ideal starting pace? First, you’ll need to establish your goal pace based on predicted race performance. Veteran distance coach Jack Daniels has simplified the correlation between predicted performance and pace by developing several charts in Daniels’ Running Formula that will help you establish race paces based on your projected finishing times over several distances. At the start of the race when your adrenaline is peaking, this pace might feel absurdly easy and your brain might scream that you are making a huge mistake. Remember that the energy you save in the beginning will enable you to run faster at the end.
It takes a lot of control to stick to the plan when a pack of jackrabbit runners stream by, but do not speed up yet. You can pass them all later when they are heaving up a lung because you are going to stick to your plan.
Do you need a real life cautionary story or two to convince you? Let’s talk about Mary Keitany’s experience at the 2011 New York City Marathon. Keitany was dead set on victory and setting a course record. It also appears that she was thinking about a marathon world record, as well. She started out fast –– very fast. At the halfway point, Keitany (1:07:56) was on world-record pace, reaching the half marathon mark faster that Paula Radcliffe (1:08:02) had during her 2:15:25 world record run on the less difficult London Marathon course. Going over the Queensboro Bridge at the 15-mile mark, Keitany had managed to extend her lead over the field to 2 minutes and 24 seconds. She was still leading when she entered Central Park, but she was starting to struggle, especially when she reached the hills. By mile 25, Keitany’s pursuers, Buzunesh Deba and Firehiwot Dado had passed her and were dueling for the victory. Dado got the win, Deba was second, and Keitany held on for third in 2:23:38. Although Keitany insisted in her post-race interview that she would repeat the same pacing strategy even if allowed do it all over again, it is clear that an overly ambitious start cost her the race.
I have learned the hard way that quick starts blow races, even though I know better. Several years in a row at the Mohawk Hudson Half Marathon, adrenaline combined with a slight downhill grade during the early miles had me going out way too quickly. The first year, I was inexperienced and didn’t know what a realistic pace would look like. The next year, I tried to start out slowly but it felt so easy that I kept speeding up…until I didn’t and slogged to the finish with some sub-optimal final mile times. Last year, I finally wised up. I added ten seconds to the overall mile pace that would bring me in under my former PR. The first miles felt easy and comfortable and I was able to find a group with which to run. We kept the pace on target, no speeding up, and I had enough energy to tackle the final two miles, which are always tough. With a reasonable pacing plan –– not going out like a jackrabbit –– I was able to take four minutes off my PR.
You might be afraid (I know I was) that if you start out too slowly, you’ll have too much energy left. True, there is nothing worse than turning in a marginal racing performance only to realize that you could have run harder. This is why it is important to assess your pacing before the race and establish an achievable goal time upon which to base your pacing strategy.
Don’t panic, however, if the first miles are slower than anticipated, especially for longer races. Sometimes, for example, there might be some traffic to wade through. Be patient! You can use the energy you save during the final miles. I have heard quite a few stories from runners who were forced to go slowly during the first miles (“I got to the start late and was way, way back…”) and found themselves with unforeseen energy during the final miles that allowed them to set a new PR.
Make a plan and try going out more slowly at your next race. You might be pleasantly surprised at the end result!Has anyone had some good experiences with negative splits? Do you have some good advice on starting out more slowly in your races? We would really like to hear from you in the comments.