Running News Daily

How Long Should Your Longest Marathon Training Run Be?

Marathon training has many nuances, but one of the most common questions is also one of the most basic. How far should you run before a marathon? What’s the longest long run you need to do in order to finish, PR, or qualify for Boston?

If you look at popular training methods, you will receive answers ranging from 16 miles (Hansons) to 26 miles (Galloway). Other plans follow the framework that a long run should not comprise more than 25% of the overall weekly mileage nor exceed three hours in duration. The wide array of answers can be overwhelming and confusing.

The truth is, the answer is not the same for every runner. These are some factors to consider when determining how far you should run before a marathon.

This post talks about the longest long run of training. This does not mean that every long run should be this length! You want to gradually increase your mileage, add in variety, incorporate cutback weeks, and include an appropriate taper.

CONSIDER TIME ON FEET, NOT DISTANCE

The marathon is 26.2 miles regardless of how fast you run. However, the training of a 3:00-3:30 marathoner will look much than the training of a 5+ hour marathoner. Several factors differentiate their training, but one of the biggest differences will be the long run.

A 5 hour marathoner will take longer to run 20 miles than a 3:30 marathoner. Yes, the 5 hour marathoner will have to prepare for more time on their feet on race day. However, a point of diminishing returns exists; too long of a long run will increase injury risk and include recovery so long that it interferes with the next week of training.

The exact duration of the longest long run during marathon training depends on your anticipated finish time. A 3:30 marathoner needs to prepare for 3.5 hours on their feet. A long run of 3-3.5 hours is both practical and safe (although be sure to consider the factors below) – roughly 20-22 miles. No need exists for the 3:30 marathoner to run for four hours in the long run.

However, a 5:00+ marathoner needs to prepare for time on their feet and will likely complete 4 to 4.5 hour long runs. They might cover 18 miles or 19 miles total in this time. It is not recommended to run for longer than 4.5 hours due to the prolonged recovery period and increase the risk of injury.

For more on the difference in long run training times, reference this article from Greg McMillan. The advice is practical to the average marathoner and scientifically sound.

CONSIDER INJURY RISK

We could try to break down all the reasons why, but one of the most basic variations between individual runners is that some are prone to injury and others are not. Some runners can make all sorts of training errors and cross the finish line of their marathon injury-free. Others endure injury in marathon training no matter what precautions they take.