Long Run : Your Most Important Run


In marathon training there is no more important run than your  Long Run.

But whilst this may seem obvious to most runners, the mention of this also brings many questions such as how far, how often, what pace, and what should I eat?

Are you running yours too fast?  

Are you running yours too fast?  

Whilst nearly everyone will agree that your Long Run is crucial to any marathon preparation, I would also add that it is often performed wrong, leaving many a runner ill-prepared when it comes to race day.

It is commonly said that many runners " run their long runs too fast, and their short runs too slow" and I would have to agree. But before we go into why this is the case, we need to understand a little about your Long Run objective.

Your Long Run serves two main purposes.

1. To develop the required muscle condition in your running muscles (predominantly legs) to allow you to complete the marathon distance. Simply this is achieved by gradually running for longer periods ( time) and longer distances ( mileage). Getting mileage or time on your legs is what is important here, and as a result you get stronger; both physically and mentally as you continue to run further on tired legs, and resist fatigue.
2. Secondly, and most importantly for the marathon is to develop and maximise your ability to burn fat as a primary fuel source and spare your limited muscle carbohydrate (glycogen) stores.
This form of energy production is called your aerobic energy system and when developed appropriately will allow you to run at faster speeds and for longer without utilising much glycogen, as fat (& O2) is the primary energy source. The more you train this system, the greater your maximum aerobic capacity will be and the less reliant you are on glycogen to fuel your marathon race. Simply, the better your maximal aerobic capacity ( or VO2 Max) the faster your marathon potentially can be).

Read more on this by our guru Phil Maffetone, and predicting marathon race times here, including  the sub 2 hour marathon here.

Using too much glycogen in your marathon race, commonly results in "hitting the wall" which occurs once your glycogen stores are depleted, and that's pretty much the end of your race as you stagger very slowly to the finish line. This is commonly the result of incorrect pacing during training combined with a poorly executed ( or no) race plan!

How to Ensure you are getting the most out of your Long Runs.

To maximise your aerobic training effect, you need to observe a few key principles;

  1. Maintain your Heart Rate at or near your Aerobic Threshold. To calculate this, there are a number of more complex methods but a simple rule developed by Phil, that I have followed for many years, to great effect is simply known as the 180 Formula. Read more about it here. The more time you spend working in this range you soon develop a feel for exactly where that limit is, and over the weeks & months you will also notice your running pace increasing at the same HR as your MAF develops. That's when you know it's working!
  2. We know that the carbohydrate stores are lowered after 90-120 minutes of running so you want to do 30-60 minutes of running 'after' this to maximise fat burning and to help the body store more muscle glycogen for future runs. So we're talking 2-3 hours for your longer runs, but naturally not every week! 
  3. As we are working with your body's ability to burn fat as a fuel source, it is important not to feed it glycogen along the way. So no gels, or sugary drinks, and no need to carb load before a long run. However, it is important of course to stay well hydrated.

In summary, keep your Long Runs long & easy for now and continue to build your aerobic base.
Later in your program I will write on how to step up your Long Run as we start to incorporate some Race Pace into these sessions as we get closer to race day.

Any queries, please ask and I will try to answer as best I can or provide references to support these principles.

As always, Run Well!

Rohan Armstrong

Passionate Running & Osteopathy