Should you run 42.2 kilometres in marathon training?

For distances shorter than the marathon, “over-distance” training is effective, and in the past, runners would typically run even the marathon distance in preparation for a marathon race. Running 42 kilometres takes quite a toll on your body; professional marathoners typically only race two or three marathons in a year, and take at least two very easy weeks to properly recover afterward. So if endurance runners typically run farther than race distance to build stamina and make their 5K, 10K, or half-marathon feel easier, should your weekly long run be over 42.2 km when training for the full marathon?

Marathon training plans are all pretty similar when it comes to the long run: it should definitely be less than a marathon in distance. Studies have shown weekly long runs of 75-165 minutes in length to be effective, while others go by volume, suggesting building the run up to 32 kilometres. Building mileage is a slow process, and should be done in 10 per cent increments between weeks.

What about those last 10 kilometres on race day? A combination of adrenaline, motivation, and tapering in the weeks leading up to your competition will carry you to the finish line. Research shows that competition improves endurance performance physiologically and psychologically, meaning your muscles can handle more fatigue while racing.

Running slower than your race pace during your longest run is also key for facilitating recovery. Since ramping up intensity and mileage at the same time is much harder on your body, it’s recommended to focus on speed during other workouts throughout the week. The ideal training for all distance runners can be broken down into a long run, two or three interval sessions and two or three low-intensity days. Overall, 80 per cent of your total volume should be completed at a low intensity.

Keep in mind that if you are approaching marathon distance at target race pace during your long run, you are essentially racing a marathon on a weekly basis. In an ideal world, this would make you get better, but the recovery cost means your training will be compromised.

Studies suggest completing long runs at a pace that is 30-60 seconds slower per kilometre than your marathon race pace. For beginners, this is a comfortable pace that still allows you to hold a conversation. These steady runs provide a foundation for building endurance, allowing you to improve your aerobic capacity and progress your pace over time. On workout days with lower volume, you can increase intensity by incorporating faster intervals or by progressing a medium-long run to end at your goal marathon or even half-marathon pace.

If you put in the work during training, your body will be capable of the most incredible things on race day.