First half marathon: how to prepare properly

1:59:30: four digits that changed the running world. At the 2026 London Marathon, Kenyan runner Sabastian Sawe became the first person to finish an official race in under two hours. What Eliud Kipchoge achieved in Vienna in 2019 only under laboratory conditions is now officially in the record books.

And this is where it gets interesting: Sawe’s pace was around 2:50 minutes per kilometre. For comparison, if you finish your first half marathon at 6:30 per kilometre, you are running more than twice as slowly as the fastest person in the world. Sound discouraging? It isn’t. It shows what sport really is: a spectrum, not a competition against the elite.

Your half marathon is not Sawe’s marathon. But it is your personal world record. And that is exactly what this guide is about.

The 21.1 kilometres are not Europe’s most popular race distance by chance. The half marathon is long enough to be a real challenge, yet short enough to train for alongside work, family and sleep.

Training for a marathon often takes 18 to 20 weeks and includes several long runs lasting more than three hours. For a half marathon, 12 weeks and a 90- to 120-minute long run at the weekend are enough. That is also why half marathon events are booming: Hamburg, Mainz, Berlin, Vienna: places are often gone months in advance.

And honestly, once you have crossed a half marathon finish line, you think differently about your own body. That is not marketing. It is physiological reality.

Before the training plan comes an honest check. A half marathon plan only works if you bring a base level of fitness with you. Otherwise, you overload your tendons, bones and motivation all at once in the first two weeks.

For beginners: you should be able to run 10 kilometres continuously or jog easily for 60 minutes without being completely out of breath. If you cannot manage that yet, it is no drama. Start with an eight-week foundation phase and plan for your half marathon in 20 weeks rather than 12.

A good half marathon plan is built around three elements: easy runs, one long run at the weekend, and a moderate tempo session or fartlek run. You do not need more than that, and for beginners, more often causes problems.

The logic is simple: easy runs develop your aerobic base, including fat metabolism, capillaries and tendons. The long run prepares your mind and legs for the distance. The tempo session makes you quicker, but it is a bonus rather than a necessity.

In the final two to three weeks before the race, reduce your volume by 30 to 50 per cent. This is called tapering, and it is where most first-time half marathon runners get nervous. Trust the plan: fresh legs on race day matter more than an extra 18 km run three days beforehand.

If you take just one tip from this article, make it this: run the second half faster than the first. This is called a negative split, and it is the strategy most top marathon runners use to set their personal bests, including Sawe in London.

The reason is simple: you start with adrenaline, fresh legs and full glycogen stores. If you run too fast now, you will pay for it twice over from kilometre 16 onwards. Lauflexikon calls this the wall. But if you tackle the first 10 kilometres deliberately more slowly and pick up the pace in the second half, you will reach the finish feeling more comfortable and often even faster.

Specifically, plan to run the first 10 km 5-10 seconds per kilometre slower than your target pace. It will feel unnaturally slow at the start. That is exactly the point. It is best to calculate your target pace beforehand with our pace and finish time calculator.

Training only works with recovery. It sounds obvious, but this is where most beginners go wrong. If you run 2 to 3 times a week, you need rest days between sessions. Otherwise, planned training stimuli gradually become overload.

When it comes to food, the rule is: nothing new on race day. Test in training what your stomach likes, whether that is a banana, bread with honey, muesli or porridge, then eat exactly that on race day. Anyone trying energy gels or new sports drinks for the first time on race day will gain unwanted experience of roadside toilets.

One extra note: tapering means running less, not not running at all. During the final 10 days, short, easy sessions keep your legs fresh. Complete rest gives you tired legs. Trust the process.

On race day, three things matter, and talent is not one of them. First, pace: start slowly. Really slowly. If people overtake you in the first few kilometres only to collapse later on the course, you have done everything right. Second, fuel: eat a familiar, carbohydrate-rich meal 2–3 hours before the start. During the run, drink at the stations, not constantly, but regularly.

Third, your mindset. Between kilometres 14 and 18, most first-time half-marathon runners find it tough. That is normal. Plan your mantras in advance: “Just three more songs.”, “To the next bridge.”, “I’m running for myself.” It may sound esoteric, but it works. Ask anyone who has finished a half marathon.

And then: the finish line. Take a photo. Be proud. You might already be thinking about the next step, perhaps a marathon. But first: recover.