The theory of relativity

Albert Einstein was a great thinker of the 20th century. Many of his quotes will remain forever engraved in history—and in our Facebook news feed. What's more, in 1905, Albert Einstein revolutionized physics by stating the theory of relativity—the famous formula E = mc2. The theory can be summed up in one simple sentence: "Time is relative to the observer." For the first time in human history, it was stated that time is not constant, but expands or contracts depending on the speed of the observer.

When I understood this theory, I was struck by its power, because I experience a version of this physical principle on a regular basis. Einstein's theory of relativity gives rise to the theory of intensity relativity: for a given distance or event, time is relative to the observer. The theory is proven by two very simple theorems that you are probably familiar with: the concept of the peloton and the theorem of time proportional to effort.

The concept of the peloton

Let's say you're riding in a peloton with good cyclists. The speed is high, you feel good, and time flies by. You feel like you could keep up this pace all day long. Then, in a split second, you feel your legs getting heavy and your breathing quickening: you're bonking! You slowly fall behind the pack, time begins to slow down until you are completely separated from the group. Your legs are burning, you want to catch up but it's impossible... Time drags on, very slowly. You realize that your day will be longer than expected.

At this point, time flies in the peloton—there's no time to get bored. Those who are still there benefit from the theory of relativity, while you are its victim. When you cross the finish line or see the convenience store, time returns to normal.

The theorem of time proportional to effort

The second example applies to people who are used to interval training. Imagine a simple formula: a 30-second high-intensity repetition followed by an equal amount of rest (30-30). You start your first effort and feel that your legs are strong. Those 30 seconds fly by. The rest period that follows seems just as short.

You begin the second effort, and time passes more slowly than during the first. Finally, you finish the intense workout and it's time to rest. Phew! Just as you start to catch your breath, it's already time to start the third effort.

This seems to last forever, with the seconds ticking slowly by on your stopwatch. Time expands. When it's time to rest, you can no longer see clearly, time contracts, and what should be a regular 30 seconds according to scientific standards seems more like 15 seconds, and off you go again! And so on until time returns to normal once your session is over.

But what causes this uncomfortable variation in time? The answer is simple: the perception of effort. The more you are able to endure discomfort and high intensity repeatedly and for a prolonged period of time, the faster time will pass. The less you are able to tolerate this discomfort, or if you have missed too many workouts, time will pass more slowly.

It's physical, and the theory of relativity of intensity proves it scientifically. A ton of scientific experiments report such perceptions. Some I have personally witnessed, but also others that have been reported to me by fellow cyclists.

Consider this when you feel like skipping a workout: you could end up being a victim of time dilation and suffer the consequences...