How Long is a Marathon

marathon running race, people feet on city road

If you are a pro-runner now or just a beginner, I am sure you have wondered, at some point, as to how long is a marathon?

A (full) marathon is 26.2 miles or 42.19 kilometers long. Now, if you have trained for a marathon or ran one in the past, the big question you may have is, why is the marathon 26.2 miles exactly? Why the 0.2 miles in the end? Because when you are finishing that last leg of the race, even those 0.2 miles can be hard to make.

But there is history behind why the marathon is 26.2 miles. During 790 B.C. a messenger in ancient Greece apparently ran for about 24 miles to spread the good news about the Greek winning a battle against the Persians. Upon delivering the message, this messenger fell to the ground and died. And to honor him, a race was created, from Marathon (which is a town 26 miles northeast of Athens, also known as Marathonas now) commemorating that distance he ran that day.

But that particular distance did not evolve to 26.2 miles until much later.

There’s more history to why a marathon became 26.2 miles long

In 1896, the first Olympic marathon was officially held in Athens. It was 25 miles long (about 40 km) and 9 participants crossed the finish line. There were many more events after that but in 1908, the marathon was finally held at the distance of 26.2 miles or 45.195 km which is the official length of the marathon today.

There is a story behind that too—during the London Olympics held in 1908, the original marathon length was 26 miles. But the marathon was supposed to begin at Windsor Castle and end at the Olympics stadium. The viewing box at the stadium meant for the Royal family was another 0.2 miles away. Hence, the finish line was extended to the full 26.2 miles then and it has stayed there since. But why we still have the marathon 26.2 miles long is still an open question.

Now that you know about the history of marathon running, the bigger question is how long does it take YOU to run that marathon? That’s the bigger challenge, and the real question is what do you do to train for the marathon to make it bearable? 

Training for a marathon does not start until you have trained your mind or made that decision to finally run it. Nothing about a marathon is normal- you are not trained to run 26 miles in a day for no rhyme or reason. No matter how much you train, it is hard on the day you run it. But good training and adopting a program that guides you through it, can actually make it possible, and frankly, even enjoyable.

Adopt a training program if you want to run a marathon

laughing mature and multiethnic sports people at park. happy gro

Training is key and if you can train with a group, even better. A coach, a guide or a friend doing the same thing can make a huge difference. So don’t do it alone, always look for a friend, especially if this is your first time.

Try a 5K or a 10K run first. Now, how long is a 10K run? Well, it is 10 Kilometers as it says, or 6.2 miles. Why is a 10K better to start? Purely for distance, and your endurance.

Endurance training for a marathon needs a) effort and b) time. Neither can be substituted. You need to work hard and you need to give it time. So, a 10K may be a great starter to a full distance marathon. If that is too much, a 5K is a beginner’s run. Remember, if you can run a 5K, you can run a 10K. And then, eventually a marathon.

Pay attention to nutrition

Healthy eating is vital when you are training for a marathon. Lighter bodies are easier to carry the distance. Which means more motivation for you to lose weight. 

In fact, many athletes will tell you that one of the best motivations they found to lose weight was to train for a marathon. As they continued to train without focusing mainly on the cosmetics, weight loss naturally happened.

That amount of exercise however, requires nutritional support. There are numerous resources for adopting a diet for marathon training. Generally speaking, a high protein, low carbohydrate diet is something you cannot go wrong with. 

Hydration matters- choose the best electrolyte mix for runners if you can

drinking water bottle runner during outdoor beach cardio workout

This is where I have seen numerous athletes (even pros) get it wrong. A marathon is 26.2 miles long. When you run it over the 4-5 hour period, you do not have time to stop and eat. You can lose 2-3 liters of body water in the form of sweat. And electrolytes with it.

Proper hydration is a must, but when you burn calories, using water to deliver nutrients- minerals, carbohydrates, even protein is a must. This truth gave birth to the concept of electrolyte or sports drinks. 

Having the right kind of electrolyte powder can make a huge difference and is now considered standard by marathon runners or endurance athletes. The electrolyte powder must be rich in sodium, magnesium, potassium and chloride, be low in osmolality making it easily absorbable and lower in the carb content. 

Improper hydration can lead to electrolyte abnormalities (low sodium in particular), muscle cramps (from low magnesium), or even rhabdomyolysis from muscle injury. The latter can be dangerous and can even lead to kidney failure from the myoglobin that leaks out from the injured muscles.
Learn more about how MAGNAK is one of the best electrolyte drinks for marathon runners here. Are you ready to hit your PR?

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Dr. Sourabh Kharait, MD, PhD.
Dr. Kharait’s sports nutrition blog is created from his “real-world” clinical experience as a Renal and Electrolyte Specialist (Nephrologist). An author of multiple, original peer-reviewed journal articles within this field for the last decade, and an inventor of numerous patented electrolyte formulas, he strives to be on the leading edge of electrolyte science for both athletes and those suffering from gut disorders. Learn more about how electrolytes interact with our body, including calcium, sodium, potassium and magnesium. Blog posts and articles related to performance and health are here to help, educate, and inform.