After running over 20 Marathons until now, 12 of them in 2018, I’ve made a LOT of mistakes. Especially when it comes to my Marathon pacing strategy. If you’ve ever ran a Marathon you’ve probably been told not to go out too fast. “Seconds gained in the end will be minutes lost in the end.”You might have a goal pace in mind, but then on race day the conditions change and you don’t know how to adjust. If you’ve never run a Marathon before you have probably no idea at all about how you should work out you Marathon pacing strategy. You are probably afraid to hit the wall and not finish at all. In case it’s your first marathon, you can read my five unconventional tips for your first Marathon here. Let me first explain why a Marathon pacing strategy is so important and than I’ll tell you my personal Marathon pacing strategy.

Energy consumption

Your body’s most important energy source is a type of sugar called glycogen, which is mainly stores in your muscles and liver. The body can also use your fat stores to generate glycogen, but this process needs oxygen. In case of moderate, aerobic exercise where the body has enough oxygen it uses fat stores and muscle glycogen stores. But the harder the exercise, the less oxygen is available, the higher the percentage of energy derived from muscle glycogen stores. Usually your body’s glycogen stores are not enough to run a Marathon on full speed. If you run too fast you would run nearly out of muscle glycogen at one point, having no energy left. They say you will hit the wall. Trust me, this is not a very pleasant experience. It happened to me once at London Marathon. I had a hard time walking and I was really dizzy and nearly collapsed to the floor. Not only did I not see or hear the amazing ambiance at the finish line, I can’t remember anything of the nice sights. It was also pretty dangerous as I could have collapsed on the floor and hit my head. Definitely not something I want to experience again. When running a Marathon you therefore need to make sure that you run slow enough to not hit the wall. But you still want to run fast enough to reach your goal.

Energy expenditure depends on a lot of things

And here the tricky bit starts. On race day a lot factors will contribute to your energy expenditure:

  • what you ate
  • the terrain you run on
  • hot or cold temperatures
  • headwind or tailwind
  • your outfit

A race pace in one set of conditions might be completely impossible in others. In addition your body will trick you by releasing a lot of adrenalin into your blood stream at the start, making everything seem too easy.

What is a bad Marathon pacing strategy

A bad Marathon pacing strategy therefore consists of going out too fast because of euphoria. Even if you run at constant effort, you will slow down by the end of the race because of reduced glycogen levels, joint and muscle pain, maybe dehydration, but definitely low overall energy levels. If you try to run faster in the beginning to bank time it could quickly backfire at the end of the race. The result: you will hit the wall and will not hit your goal.

What is a good Marathon pacing strategy

In a good Marathon pacing strategy you want to save energy and not bank time. You want to go out slower than how you feel in the beginning. But how slow should you go? I’ve developed my own Marathon pacing strategy over the years, which is based on a very simple rule somebody once told me: “when running a Marathon the half way mark is 30 km.” If this is subjectively true (and my experience confirms that) I want to have at least 50% of energy left when I hit the 30 km mark. By scaling this up, I am aiming to still have 75% of energy left at 21 km, and 90% at 10 km. So I roughly aim for:

  • 10 km: 90%
  • 21 km: 75%
  • 30 km: 50%
  • 40 km: 10%

How to I assess this? Actually I just ask myself: “How are you feeling right now?” at these checkpoints. At 10 km in I should still feel really fresh. If I already feel a bit exhausted, I am going to slow. At 21 km I should still feel pretty good and absolutely optimistic. At 30 km I should feel medium exhausted, but confident. And at 40 km I should have enough energy left to enjoy the cheers of the crowds and the ambiance at the finish line.   What is your Marathon pacing strategy? Do you just run or do you have an accurate strategy?  


Do you want to run a Marathon yourself? Check out my blog post on the best Marathon gear, and tips for your first Marathon.