How many km (miles) per week to prepare for a half-marathon?

Volume is an important factor in running performance. This is especially the case when distances get longer. If you wish to embark on this beautiful distance that is the half marathon, we will indicate the recommended weekly volume based on your profile. Our goal is that you have understood how many km per week suits you best to prepare for a half marathon.

As its name suggests, the half is a half marathon. The exact distance corresponds to half of a marathon, which is exactly 21.095 kilometers. Being able to continuously run this distance is a great achievement. However, this great challenge is accessible to everyone, provided you prepare well.

In terms of elevation, it varies from race to race, but generally it is quite low on road races. For example, the Paris Half Marathon has 80 meters of elevation gain, the Sables d’Olonne only 10m, while Biarritz has 250 meters. 

While extra-terrestrials like the world record holder, Jacob Kiplimo, or the Frenchman Jimmy Gressier manage to finish the half marathon in less than an hour (meaning less than 2 minutes 50 seconds per kilometer!), this is obviously not the case for amateur runners. In our great running survey conducted among Campus users, it turns out that the average time for a half marathon is around 2 hours of effort, regardless of gender and age. This corresponds to an average pace of 5 minutes and 40 seconds. You will find all the details in this dedicated article. 

The less experience you have in running, the more you should extend your preparation duration. If you are a beginner, we recommend choosing a training plan half marathon of at least 16 weeks. This way, you can start with a low weekly mileage to gently get your body used to these new demands. Then, your training volume will increase very gradually over the weeks. In a third step, we can add more intensity to your program, as you will be able to well assimilate this new stress. This progression will significantly reduce the risk of injury and allow you to truly discover your potential. Eventually, you will enjoy the race day more. 

If you are already running regularly, at least two or three times a week for several months, and you are not coming out of a break, it is possible to reduce your half marathon preparation time to 10 or 12 weeks. However, remember that a longer structured preparation focused on the half at the end will often be beneficial in terms of enjoyment and performance. 

In itself, the preparations for a 10K and a half marathon share many common points. The paces/speeds for 10 km and half marathon are not very far apart, about a 1 km/h difference for a well-trained athlete. The work on MAS (Maximal Aerobic Speed) and around the 30' and 60' thresholds is common to both distances. 

The most notable difference between a 10km (6,21 miles) training plan and a half-marathon prep is the long runs and specific work. But no way to multiply outings beyond the 2h like in a marathon preparation. Here, their duration will not exceed 1 hour 30 to 1 hour 45. These workouts have a doubly interesting role. They work on both your physical and mental strength. These qualities are essential to approach your half under the best conditions and manage to maintain your pace in the second half of the race. 

When you run more than 3 times a week : the duration of your long runs must increase very gradually — no more than 5 to 10 minutes per week — always with the aim of limiting the risk of injury to a maximum. The more accustomed you are to running, the better you will assimilate the long outings. Hence the importance given to the overall volume in a half prep. 

Ultimately, one of the key points is to successfully accumulate a certain number of kilometers/miles in training. A volume adapted to your current abilities allows you to acquire a good endurance base depending on your finisher, performer, or elite goal. It promotes better recovery after intense sessions as well as a greater variety of training sessions.

That's not all. The more you run, the more you will naturally strengthen your muscles, tendons, and joints. This is very interesting for pushing muscle fatigue to the end of your half marathon. 

The following ranges are intentionally quite broad. If you are new to running, just one rule: start slow! The repetition of impacts is traumatic if your body isn't ready to handle them. Focusing more on the frequency of the sessions rather than their duration, we recommend starting with 3 running sessions per week. 

These will first be easy jogging runs, or even walk-run intervals. The first step of your progress will be to succeed in running for 30 minutes without stopping. Once step 1 is validated, your total mileage will be between 15 and 20 km (9,32 to 12,43 miles) per week. It is preferable to ensure you can run for 30 minutes before embarking on a half marathon plan, both physically and for enjoyment. 

This mileage will increase very gradually until reaching 40 to 45 km at the peak of your preparation, three weeks before your half marathon. Your weekly program will include an easy jogging run, an interval session, and a long run. If your body responds well over time to this rhythm of three workouts per week, a fourth workout can be added. In addition to running, it is interesting to practice strength training. 

If you are already used to running several times a week, you can start your half marathon prep with a mileage ranging between 30 to 40 kilometers per week, with 4 to 5 sessions per week. Your mileage will gradually increase to 60 to 70 kilometers (37,28 to 43,50 miles) for your most intense week. There's not much point in exceeding 1h45 during your long runs as it could cause over-fatigue and hinder your recovery and subsequent workouts. Just like for a beginner runner, remember that recovery is an integral part of your training and progress. Training well also means knowing when to back off when necessary!

Are you already completing one or more half marathons and aiming to achieve your PB? Know that it is possible to tap into a good part of your potential and get very good times without increasing your weekly mileage dramatically. If you aim for performance, a long plan with 5 or 6 sessions and between 60 to 80 kilometers (37,28 to 49,71 miles) per week will offer excellent results compared to the investment made.

The best specialists in half marathon easily exceed 150 km per week. You could be tempted to emulate them to progress faster and break your times. 

In reality, not everyone can run 100 km (62,14 miles) per week. Reaching such a volume requires time and progressivity. It is essential to consider your history. Everyone is different, has their own constraints, running history, and injury history.

That's why copying alike mileage isn't effective from one person to another. Maybe a friend of yours can easily handle a 60-kilometer (37,28 miles) running week while your current recovery capacity is 40 kilometers (24,85 miles). 

The “good mileage” is therefore the one you will manage to assimilate well. There can be no progression without recovery. An excess of volume can hinder this process, or even lead to regression. The key is to find your sweet spot, meaning the right amount of training. A volume that allows you to train enough to finish your half marathon while having the best possible experience. But not too much so as not to risk arriving worn out on race day, or worse, getting injured during your preparation.
In conclusion, running a half-marathon race is a great challenge and requires a well-structured training schedule. Unlike a full marathon which covers 26.2 miles, the half-marathon distance is more accessible for many but still demands respect. How long is a half-marathon? It's exactly half of the marathon distance (13.1 miles), making it a significant distance race.
To determine your ideal weekly mileage, consider your current fitness level and how much time you have before the half-marathon event. There are numerous half-marathon training plans available, but the best one for you will be personalized. The goal is to build up your endurance gradually so you can achieve your desired half-marathon time without overtraining.
The key to successful half-marathon training is consistency and listening to your body. Don't increase your mileage too quickly, as this can lead to injuries. Focus on a gradual build-up, incorporating long runs, tempo runs, and recovery days. It's crucial to stay motivated throughout your preparation. When you're ready to start training, remember that the "right mileage" is all about finding a sustainable volume that allows you to enjoy the process and cross that finish line strong.

PS : for a balanced, personalized, individualized, and evolving dosage, simply awesome! I've got a good plan for you 👇