It goes without saying that one of the first things you should be looking at when it comes to marathon shoes is their level of comfort. They say that you should run in your potential new footwear before you buy it - so do exactly that! Do a small test run as soon as you unpack them, or around the store - you will immediately notice whether or not the trainers are comfortable enough for you.

The key factor here is how the interior of the design is constructed. There has to be plenty of room in the toe box and heel areas, which we will cover in our next section, titled Fit. But there also can't be any pinching or rubbing, any seams digging into your skin or part of the sole awkwardly poking you. Any slight disturbance that you feel during the initial wear of the trainer will only increase tenfold once you're actually on the track.

The entrance and tongue of the trainer should be padded so as to avoid chafing during long runs, and plenty of cushioning is a must unless you're going for a minimalist type of style, which we will also talk about in the Weight section.

Make sure that your feet feel supported but not restricted, and that the trainers are flexible but not flimsy. Striking a balance here is key.

Not every trainer will suit every runner. Keep in mind that what your friend and fellow marathon runner might like or find comfortable may not be the same for you. Be patient, and don't settle for less! Come mile 20, comfort levels of design will become of the utmost importance in securing that finish line.

It goes without saying that you should look for the right footwear size and that the pair of marathon shoes you're looking at doesn't fit you too tightly or too loosely.

If you're an experienced runner, you are probably already well-versed in finding the right fit and knowing what to look for. However, if you're new to the long-distance running game, we have some tips and tricks for you.

• The design you're considering should be fitted to your longest toe. Sometimes this can be the big toe, but sometimes this can also be the second toe, so be careful of that.
• The heel area - the heel counter - of the trainer should be snug. Your heel shouldn't feel like it's in a vice grip, but it also should absolutely not be slipping out of the design as you walk or run.
• The toe box needs to have enough space so your toes can comfortably spread. Toe-splaying is essential in keeping your balance and stability as you pound the pavement mile after mile, and they need to have room for that. Again, don't go for too roomy - find what works for you.

In terms of when to try on your footwear for the first time and determine the fit - keep in mind that at the end of the day feet tend to swell. Feet also swell during a marathon run, and thus you should consider the right fit when your feet are at their biggest, so to speak, so there are no hurts or discomforts later on.

When you're looking at the weight of marathon shoes, this is where it gets a little tricky; there are trainers which are minimalist, but there are those which are maximalist as well. Which ones you prefer and which ones suit you better (or perhaps both types do!) all comes down to your personal preference and style of running.

Maximalist trainers have plenty of cushioning to soften the blow of each heel strike and to provide maximum comfort and endurance on long runs. This may be beneficial for beginner marathon runners, who are still not used to the strain of such a long race.

However, nowadays more and more athletes turn to minimalist footwear. This type doesn't have as much cushioning - if at all - and is great at increasing speed and performance. Minimalist runners don't even need cushioning since they run faster and thus spend less time on their feet overall.

There are athletes who use both types of trainers. They train in maximalist footwear, then switch to the minimalist a couple of weeks before the big day.

Again, which option you go for depends entirely on what your priorities are - comfort or speed; support or performance. In our list, we have ranked the designs according to their weight from the lightest at the top to the heaviest at the bottom, so you can have an easier time sorting through them and picking out which one you like.

Running for miles on cold hard concrete can take its toll on your body. Your heels pound the asphalt without mercy, and the force of each landing transfers up to your foot, to your joints such as knees and ankles, and even up to your hips. Over time, this type of repeated impact can lead to some health problems, such as heel pain, shin splints, and even damage to your joints.

This is why it is essential that your running footwear has shock-absorbing materials. These absorb the shock, as their very name says, and distribute it across the trainer instead of letting it pass through to your legs. Not all of the impact force can be successfully neutralized, but shock-absorbing materials definitely help when it comes to reducing the risk of injury and pain later on.

So, what exactly are shock-absorbing materials?

Let's start with the obvious one: EVA. EVA is short for ethylene-vinyl acetate, and it is most commonly used as a foam in footwear midsoles and insoles. It is fantastic at absorbing shock - EVA compresses when your heel hits the ground, but then springs right back up into its original position, ready to absorb more impact on the next heel strike. There isn't a sports footwear manufacturer in the world that doesn't use EVA in their designs, including big names such as Nike and Adidas.

However, those very big brand names also sometimes come with innovative, high-tech features that may not necessarily include EVA but which are also geared towards absorbing shock. You have seen in our list that plenty of our options come with sophisticated technologies and characteristics unique only for that brand.

We understand that these can get a little confusing, and trying to choose the right technology for yourself may seem like a daunting task. The important thing here is to not get caught up in all the specifications and details on paper - what is crucial is how that technology works for you.

If you feel comfortable, pain-free, supported and able to finish that marathon, then it doesn't matter what the exact material or what the brand name is. What matters is that you've found the right model for yourself and you can go the distance!

Finally, we arrive at our last criterion, but one which is certainly not the least. With so many hours spent training, and even more, spent running actual marathons, marathon shoes can take quite a beating. They are used frequently, and usually on hard, unforgiving surfaces, and thus the question of how long they can last is a valid one.

Sportswear manufacturers have come up with an interesting way of measuring the durability of long-distance footwear; namely, it's not about the time the shoes last for, but about the mileage covered in them.

Standard running footwear lasts anywhere from 300 to 500 miles, which is considerable. Minimalist footwear we mentioned earlier, because it doesn't have as much substance or materials to it, lasts a little shorter: from 200 to 400 miles.

If you're wondering whether or not your marathon shoes need replacing, here are a couple of things you can look for:

• Outsole Wear: If the patterns on the outsole have lost their clarity and become muddled - or even completely worn away - this design no longer provides adequate traction and should be replaced.
• Midsole Feel: This is not something that you can see, as the midsole is built into the design, but it is something that you can feel - if your trainer is no longer adequately bouncing back or its midsole is no longer returning to its original position, you will feel as though the trainer has gone flat or dead.

If you are serious about your running and about your health, it is imperative that you get yourself a new pair of shoes as soon as you realize the old ones aren't doing it for you anymore. This will not only keep your performance at an all-time high but will also spare your feet, muscles, and joints from unnecessary strain.