Pacing is the most important aspect of marathon racing. Your success in a long race depends on conserving your energy during the crucial first hour. That’s when your body is running on the greatest proportion of its limited stores of muscle glycogen.
You will hit the wall once you run out of muscle glycogen. If you don’t want to suffer the ignominy of a crashing slow down in the last hour of the race, you must wait for fat metabolism to turn on during the first hour. Once you are running efficiently on a combination of fat and glycogen, you can run for a long time at your desired race pace.
There are two ways to think about your race pace: It’s the average pace that you are capable of holding for the race as a whole, and it’s also your pacing strategy. You won’t really know how to predict your average marathon pace unless you have run a marathon recently. Training runs are not good predictors because racing is radically different from training.
In lieu of running a marathon, you could do a series of shorter practice races (up to 30K) or a series of long time trials. Time trials and practice races can give you the experience necessary to predict a reasonable and accurate finish time for a marathon. Once you are able to predict your average pace for the whole marathon, your pacing strategy will determine whether you achieve your personal racing goal.
Do you personally want to finish and enjoy the race, or do you mostly want to compete and perform? The way you answer this question will determine your pacing strategy. There are only two effective ways to pace a marathon, and they both involve going out slowly. But how slow is slow? Our racing experience in BC Endurance Trainings indicates that you should complete your first hour between four and eleven percent slower than your average predicted marathon pace.
The slower you run the first hour of the race, the faster you’ll run the last hour. Therefore, if finishing and enjoying the race is your goal, then you should complete your first hour about 11% slower than your average marathon pace. You won’t finish the marathon with your fastest possible time by using this strategy, but you’ll be amazed by the energy you still have at the finish. And it’s fun to blow by people in the last hour or two of a marathon. This pacing strategy involves a gradual increase in pace from start to finish of the race.
Some athletes are more concerned about how fast they go than how much fun they have. If you are concerned about your finish time, you must run as evenly as possible, while also allowing time for your body to warm up fat metabolism. Our experience indicates that finishing your first hour 4.2% slower than your average predicted pace will enable you to achieve your fastest possible finish time.
Running 4.2% slower than average marathon pace for the first 10K of a five-hour marathon means you will have lost three minutes. Those three minutes can be made up easily in the middle miles once you are running efficiently on fat and glycogen. This is so simple, yet a five-hour marathoner who goes out three minutes faster than five-hour pace ends up running six minutes faster than he/she should.
Beware. Abundant energy and an aggressive racing attitude can wane and disappear by the mid-point of a long race. If you want to finish with a best effort and your fastest performance, you must be prepared to hold yourself back in the early going, shave a little time in the middle miles, and hold on for dear life at the end.
Pacing is the name of the marathoning game. If you can predict your time to the minute, and you can be honest about your personal goals, then you ought to be able to calculate your pace for the first 10K and pace yourself accordingly for a successful marathon experience.