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Marathon training: Preparing for the worst to perform your best

marathon training

Conquering a marathon is every runner’s ultimate goal. For those who haven’t yet taken on the challenge, 42km seems unimaginable. For those who have, they know the toll it takes on the body. However, no matter if you’re a regular marathon runner or if it was your first one, the body undergoes tremendous physical constraint. So before you step up to the starting line, we want to prepare you for what you might face. Here are some of the scientifically measured physiological systems that are most affected during or after a marathon:

Skeletal Muscle

Skeletal muscles are attached to bones by tendons and produce all the movements of the body parts in relation to each other. Studies show that intensive training and continuous impact before and during the marathon itself, significantly damages these muscles, resulting in inflammation and microscopic muscle tears. This causes muscle soreness and fatigue and is more than likely the reason behind that unbearable pain you experience in your calves once you reach the finish line. Should you be worried about this? It’s normal for marathon runners. 42km is an extremely long distance so of course your muscles are going to be pushed to their limits. The most important thing is that you allow your muscles to rest and repair afterwards. They say it takes 2 weeks after the marathon until your muscles regain their full strength. So give them time.

Immune System

With such a strain on the body, it’s no wonder that after 42km a marathon runners immune system takes some bashing.  The “Elite Athlete Paradox” theory, highlights that although exercise is good for mental and physical health, intense, long duration exercise sends the body’s naturally built-in healing processes into overdrive, therefore temporarily compromising the body’s ability to defend itself. This leads to a suppression of the immune system for a short period of time, meaning you are likely to pick up a cold shortly after the race. For this reason it’s really important to focus on eating healthy and nutrient rich foods with lots of vitamins to strengthen the immune system.


Staying sufficiently hydrated is an important factor during a marathon in terms of safety and performance. If you are dehydrated your blood volume decreases, your heart rate increases and the heat loss is impeded. This causes you to slow down your pace or even to drop out of the race. For the optimal hydration status there should be a balance between sweat losses and fluid replacement. As soon as lost fluid is not adequately replaced, dehydration occurs. Your sweat rates can increase by warm, humid weather conditions, especially when it’s unexpected. The result is a faster onset of dehydration and an increased risk of early fatigue and heat-related illnesses. Everyone’s sweat rate is individual and dependent on gender (men sweat 30% more than women of the same weight), on fitness level and on running pace. But on average an athlete is said to lose around 1 litre of sweat per hour.

As well as dehydration, there is also the risk of drinking too much fluid, which can lead to a terrible condition called exercise-associated hyponatremia. But don’t worry about this too much. It happens mainly to slower marathon runners who drink more fluid than they lose in sweat – something pretty unlikely to happen to a Free Athlete.

The goal for your safe marathon experience is to balance fluid intake with sweat loss to avoid both dehydration and hyponatremia. If you are a faster runner (under four hours) you should be more concerned with avoiding dehydration than developing hyponatremia. Everyone is different and there is no single recommendation on how much you should drink. Therefore learning your individual hydration needs to achieve your best results should be a key part of your marathon preparation. When you know you’ll sweat a lot, drink 10-20 ounces of fluid about an hour before the race to help you start with adequate fluid in your body.

Let's recap:

Still want to run that marathon? Of course you do! We don’t want to put you off the race. Simply prepare you for what you might face. If you train properly, fuel your body effectively and are prepared for what might come, the negative effects will be minimal. Take our word for it, the feeling of accomplishment when you pass that finish line will outweigh any pain you experience.