Am I fit enough to run a marathon?

One of the most common questions our Fit School Run Club members (or want to be members) ask us is: Am I fit enough to run a marathon?

Some don’t even like to admit they want to run a marathon because they think it’s beyond them.

The simple answer is yes. You CAN be. But it’s not just about running increasingly longer distances.

Whether you want to run enough to make it part of your weekly fitness routine, run a 5k or run a marathon there are three vital elements to running that we help our members with:

  • Fitness;
  • Conditioning; and 
  • Strategy.

They are all part of fitness but most people fail to move beyond the distances to run. Strategy, fitness and conditioning can all get you to the start line of your marathon – and hopefully to the end! Just trying to run further, won’t necessarily get you there.


Strategy is to do with pace. We have helped many people improve their personal bests just by learning how to pace themselves. Most people have no idea what pace they need to hold and how they can lose time later by going too quickly at the start. For example, you may want to run a 3.06 marathon, so you can enjoy it before attempting the sub 3 hours marathon which will feel pretty tough. These are actual numbers we’ve used with clients recently. Strategy can be that specific.


Fitness is how your cardiovascular system copes with the demands of running so you can run further and faster with less effort.

There are many miles of blood vessels that make up your vascular network and delivering oxygenated blood to working muscles, while taking deoxygenated blood back to the lungs.

One element of fitness is how much blood your heart can pump per beat. This is known as your cardiac output. People who are very good at endurance type exercises, tend to have a good cardiac output as your ability to sustain effort is directly linked to how well your heart can supply oxygen to working muscles and transport Co2 and waste products back around your body. Most unfit or people new to running will feel a lack of energy or a sudden feeling of fatigue when trying to exercise for longer periods and this will be one of the main reasons they want to give up.

As your heart gets better conditioned, exercise will feel easier.

Resting Heart Rate

So what’s going on? The left ventricle adapts by stretching (due to the demand placed on it during exercise) and in some cases becomes larger. Your heart is a muscle. A larger muscle will tend to be able to pump more blood than a smaller one. This will create a lower resting heart rate as it needs to beat less due to the increase blood it is pumping out per beat. Your resting heart rate should be around 60. A trained heart will be in the 50s and an elite resting heart rate will be 40 or under.

If you are new to exercise, I would test your resting heart rate at the start of your programme and you should see it drop as your heart gets more conditioned.  I always advise people to find any form of exercise to train this element of fitness. It doesn’t have to be running.


Conditioning is to do with how your body resists the forces which impact the body when you run. This also includes technique which helps you to become more efficient when you run.

Most running programmes only look at running fitness. For example:

Here’s your 5k plan: Gradually increase your distance over several weeks and you will be able to run 5k.

The problem with this plan is progression is never perfectly linear for most people.

Everyone goes on their own journey.

Some get injured, some can do more while others should do less.

Also, neglecting conditioning is one of the biggest mistakes you can do.

Here’s why:

The amount of force generated when running is roughly 2.5 x your body weight. This force goes somewhere and this is what either helps or hinders your running.


Poor running conditioning will inevitably lead to injury, since your weakest point will break down. Especially when you try to increase the distance you run. For many people, this tends to be your knees, hips or ankles. For some less fortunate people, it creeps up to their back.

This is particularly true if you are starting running from a de-conditioned state. Perhaps you’re coming to running after a long period of being sedentary. Perhaps you’ve never run before but have decided to take it up as part of a weight loss programme.

Running is great but injuries are not and as much as we love inclusive running groups like ParkRun or programmes like Couch to 5k we think it’s really important to incorporate all 3 elements into your training so you can enjoy running now but also future proof your running career and get you to that marathon line!

If you aren’t disciplined to do a basic running conditioning programme lasting 8-12 weeks, then you really need to get to a group who will do this, before you decide to increase your volume of training.

We’ve just launched our Now to 5k Running Group to accompany our Run Club. Do get in touch to find out more.

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