Murphy’s Law of Running: The Stuff That Always Happens in Training

5 February 2026 3  min reading
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According to Murphy’s most famous law, if something can go wrong, it will eventually go wrong. It’s a half-joke, half-observation of life. It works surprisingly often. You can see it in large projects, office work, and completely ordinary activities, such as morning hygiene routines. Running is no exception. Based on my experience with training and competitions, I decided to examine how Murphy’s laws apply to our sport. It turns out that runners encounter these laws more often than they would like to admit.

These laws are named after Edward A. Murphy, Jr., an American aeronautical engineer who worked on accident research and safety in the 1940s.

How can Murphy’s Law be applied to running? To the weather, for example:

  1. The jacket law: If you go out for a run expecting rain but don’t bring a rain jacket, it will rain. If you wear a jacket while training, it never rains.
  2. The law of rain: It will start raining five minutes after you start training and stop five minutes before you finish.
  3. The law of good weather: On the day you have off from running, the weather is always perfect for running. When you have a training session planned, it’s cold and raining.
  4. The law of headwind: When you run a loop, the wind always changes direction at the same time as you, blowing in your face the entire time.
  5. The law of the time of day: No matter when you start your run, you’ll feel like another time of day would’ve been better.

The law of equipment:

  1. The law of technology: The GPS that has faithfully served you for years will lose its signal in the most unfamiliar part of your route.
  2. The law of nines: When you set a personal record in a 10K race, your watch will measure the distance as 9.99, and your app won’t record it.
  3. The law of size: When you order new running shoes online, they will turn out to be the wrong size, requiring an exchange.
  4. The law of color: When you try on several pairs of running shoes, the most comfortable ones will be the ugliest color.
  5. The law of new shoes: When you go out for your first training session in new, brightly colored shoes, you can be sure that you will accidentally step into a muddy puddle.
  6. The law of shoelaces: Shoes that never came undone during training will come undone during a racing.
  7. The insect law: The moment you take your glasses off while running, an annoying insect will fly into your eye.

On the route:

  1. The red light Law: If the traffic light at the intersection you are approaching can turn red, it will.
  2. The green light law: When you stop to catch your breath at the light, it turns green.
  3. The law of the barrier: If your route takes you across a railroad crossing, the barrier will close in front of you.
  4. The law of necessity: Whenever you urgently need to find a secluded place, you find yourself far from one.
  5. The law of the missing piece of paper: When you forget to bring tissues or a piece of paper from home, you can be sure that you will absolutely need them.
  6. The law of two cars: When driving on a narrow road, two cars traveling in opposite directions will pass each other at the exact moment you pass them.

Health:

  1. The law of the straight road: If you fall during training, it will be on the straightest and most even road.
  2. The law of colds: You will always catch a cold a few days before your most important competition.
  3. The law of sudden injury: Just when you’re in top form, you’ll suffer an injury that requires you to take a break from running.

What about you? Do you know any other Murphy’s laws? What else can be added to the list?

Pawel Matysiak
Post author Pawel Matysiak

I am an amateur runner and have participated in 1000-meter runs on the treadmill, half marathons, marathons, and ultra-marathons. I give professional advice on choosing the right running shoes. I have more than I can count at home.

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