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How long is your longest marathon training run?

After last weeks post on ‘running at different paces’, hopefully some of you have been able to get out and do just that. Whether it be a slower than normal recovery run, or an out and back progression run – there are many different ways to vary the pace and I strongly encourage everyone to do so regularly.

In this post I want to focus on the second similarity that I often find amongst the runners I speak to – and this is the distance of the longest long runs during marathon training.  Put quite simply, in nearly all cases they are not long enough. By this I mean a maximum of 20 miles. This would go along way towards explaining why many runners struggle in the last few miles of a marathon or why their marathon PB’s are out of sync to what they have done over 5k-1/2 marathon.

Cutting straight to the chase, if your longest run is only 20 miles then consider the following points

  • The numbers: 26.2 – 20 = 6.2. This is the distance you are selling yourself short of if your longest run is only 20 miles. A full 10,000m for those metric fans out there. Think how far 10k is at the best of times, then think about having to run one when you are on your absolute limit having just ran 20 miles.
  • Confidence: Imagine getting to the 20 mile marker in the marathon feeling good and knowing roughly what the last part of the race is going to feel like (because you’ve been there several times in training). This is what those big long runs will enable you to do. This is a huge difference to arriving at 20 miles and then every step beyond that being further into the unknown.
  • Comfort zone – two words that came up last time and probably the main reason why people avoid the ‘long’ long runs in training. Running 24 miles is probably not going to feel great at the time, and all those mental demons will really be coming into play. Getting comfortable being uncomfortable can only really be achieved by going for it fully.
  • Marathon specific training – The most specific way to train for a marathon is surely to run a marathon (or at least close to one). By doing this you know that you are preparing properly for the challenge to come on race day .

In terms of the key questions that you may have, they are written below with my thoughts

Q – If 20 miles is not long enough, how long should I go?

A – If you are brave enough and experienced, there is no reason why not to go the full way (or further in some cases), failing that I would never want to send someone to a marathon startline who hasn’t ran at least one 24 miler.


Q – Do I just go straight in with these big long runs?

A – Absolutely not, being able to handle the shorter runs first and building gradually towards the 20+ milers is by far the most sensible way to proceed. Giving yourself plenty of time to build for a marathon is key (especially if it is your first one).


Q – How many of these runs should I do?

A – Again this will depend on experience and fitness, though perhaps a 20, 22, and 24 mile run during a build up would be a good place to start


Q – How fast should they be?

A – This is a £64,000 question. Too fast, too often and you risk overtraining. Too slow and they risk being not specific enough. Ideally close to race pace, or sections slightly slower / quicker so that the runs do resemble something like what the marathon will be like. There are lots of different ways to do these long runs and this will be the subject of a future post.



Whilst ‘getting round’ a marathon will certainly be possible without these big long runs, hopefully by virtue of reading this you are keen to do more than that and want to get the most out of yourself. Doing the most specific type of training a marathoner could do (running far and hopefully fast) is the key to achieving this.





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