Your brain is lying to you about how tired you are

I want to talk about fatigue today.

It's something we all experience, yet we don't fully understand it. Even from a scientific standpoint, there's still a lot of ongoing research and competing theories.

Here's one that recently blew my mind.

The widespread belief is that we become physically tired when we reach our muscular limits. The muscles run out of oxygen, or start to suffer damage from the build-up of waste products like lactic acid (if you have ever held a Warrior 2 for over one minute, you know what I'm talking about).

even she looks like she's fighting for her life and she's not even real

But a scientist called Tim Noakes has a different theory which is gaining a lot of traction, particularly among psychologists.

His idea is that it's not your muscles that dictate your fatigue. It's your brain.

Your brain essentially creates a buffer. It sends you the signal to stop well before you've actually reached your limits. And it does this to protect you, because it knows you'll need those muscles for something else afterwards.

If you think about it from an evolutionary perspective, it makes a lot of sense. Go back to the time we had to hunt our food. Our brains didn't allow us to use all of our muscle capacity for the hunting part, because we still needed to carry our loot back to camp.

And you've probably noticed this yourself. Even when your legs are completely shaking after a tough workout, and you feel like you've given 100% effort... you can still walk home from the gym.

So your brain is making a fairly conservative estimate of the energy you can spend, based on a whole range of variables: the oxygen levels in the air, how confident you feel, how long and intense the task is, your emotional state, etc.

It's constantly reassessing, too. When we see an athlete getting a second wind in the last stretch of a long run, that's their brain allowing a bit of this stored energy to come to the rescue!

I wanted to share that with you because I find this liberating. Because it means that most of the time, we have more in the tank than our brain is letting on.

As Noakes puts it: "You do not have to believe everything you think and feel."

Something to sit with this week 🌱

Clem