Mental fatigue in football decision making shows up as being a fraction late. A fraction late to read the pass, a fraction late to react when a player goes past you, a fraction late to start the movement. Your legs can feel completely fine. The problem is the command from the brain, and a tired brain sends a weaker, later command.
Watch: the video this post comes from
At a high level, a fraction is everything. One step is the difference between getting there and watching it happen.
The day your legs are fine and you can't get up for it
Every player knows this day. Nothing hurts. You're not sore. And you just can't get up for it. There is no energy to take on the next challenge, the next press, the next run in behind.
That isn't you being soft. It's chemistry.
Your motor cortex, the part of the brain that sends the command to move, has its own brake. That brake is a calming chemical called GABA. When you're fatigued, the brake gets stronger. A tired athlete's brain literally sends a weaker command.
Higher up, the balance between two other brain chemicals, serotonin and dopamine, shifts. Dopamine is a big part of your drive. When the balance shifts, your drive shifts with it. See?
Mental fatigue in football decision making: the study I quote
There's one example I use in my videos. Well-trained footballers were mentally fatigued with 30 minutes of hard concentration tasks. No running. Then they made football decisions, and those decisions were both less accurate and slower.
Nothing had touched their legs. The command was late.
That's the part players miss. You can do zero physical work and still turn up to a game with a tired brain. Thirty minutes of hard concentration was enough. Stack a heavy block of training on top of that and it all comes out of the same tank.
Speed is processing, not just legs
I saw this first-hand. In 2011 I was on trial with Rapid Wien's under 18s in Austria, playing with Louis Schaub. The way he could turn, the speed he made decisions, the coordination he had with the ball. It wasn't speed. It was the processing. And I thought, there's another level to this.
That's why I say speed has more than 100 subcategories. Reaction, the first 5 m, the start of the movement, reading the play. A player who reads it a fraction early looks faster than a player who runs faster but reads it late. Right?
So when your decisions are slow, the answer isn't always more running. Sometimes the answer is less load, so the brain can fire properly again.
Think of your body as a sound desk
Here's the way I explain it.
Think about a sound desk. Each session you push every fader up, and the next day they come back down on their own. But keep pushing them up night after night and the whole desk starts running hot. The master volume drops, and turning the faders up doesn't make it any louder.
The faders coming down overnight is session fatigue, the tiredness from one session or one match. The whole desk running hot is built-up fatigue, weeks of hard work without full recovery.
When the desk is running hot, trying harder doesn't help. The more you try doesn't always equal getting more out of it.
How long it takes to clear
Session fatigue clears in about three days. Built-up fatigue takes far longer. In our own testing across around 1,000 athletes, getting back to 100% neurological freshness takes 7 to 24 days after a single flat out speed session, and can run past 50 days after heavy build-up.
Those are our own figures, not a published study. And they are days to 100% neurological freshness, not days until you can train. Freshness is when your decisions come back faster than before.
What to do about it
- ✓Don't judge yourself on one bad game. If you read everything late, ask whether it was your brain, not your ability. How do you know it wasn't built-up fatigue?
- ✓Protect the day before a game. No gym the day before. Keep it fresh.
- ✓Don't stack extra sessions on rest days. We don't want too much fatigue in the same 24 hours.
- ✓Track one number. A 10 m sprint or a jump at the start of your first session each week, done the same way. When the number is flat and your legs feel great, the desk is running hot.
For the full chain of how this works, read signs of CNS fatigue in athletes and your legs feel fresh, your nervous system isn't.
The bigger picture
At Ambition every session is timed and reviewed on film. We look at the whole player, not just how fast his legs go: the start of the movement, the decision, the first step. We assess, find what's costing him the most, fix it in order, and measure. Mental fatigue is one of those costs, and most players have never been told it exists.