The following quote comes from the book The Brain Always Wins.
“‘So let’s be clear about it now: mental toughness is the process of training that includes stress inoculation and resiliency building through iterated stress and rest leading to an increased capacity for emotional understanding, energy maintenance, information input , and work output. Don’t get this concept confused with winning and losing – mental toughness no more guarantees outcomes than having greater strength or being faster does. ‘Exercise is one of the principle factors in maintaining mental toughness, because stress is the stimulus for growth whilst rest is where it all comes together. An under-rested brain and central nervous system is weakened or degraded and the more it is under-rested the more it is unable to be mentally tough. We are born mentally tough – a lack of training or too much training and inadequate rest disturbs that balance.”
The authors of the book clearly make a strong link between fitness and fatigue and mental toughness. It’s pretty easy to understand, I think.
The fitness angle
Consider this. You need to make 10 consecutive swings. If you are in good condition, your last few attacks will probably be about as good as the first few. When I say “good” I mean as focused and skilled. They’re about as likely to score.
What happens if you’re in bad shape, though? How do those last few repetitions look? Pretty ugly and ineffective, right? You’re just trying to run, jump, and swing. Any thought to making a good attack goes out the window. Basically, you’re doing the minimum because that’s all you can focus on.
The fatigue angle
Even if you’re in great condition, though, you still need rest to recover.
Think about it this way. Let’s say a hitter gets 50 swings in a match. If the hitter is well-conditioned the last few swings are probably at close to the same level as the first few. That’s because the swings have breaks between them.
Imagine what would happen if they came consecutively. It would be like the out-of-shape person trying to do 10 in a row. They don’t get enough of a break for their system to recover, so performance degrades. In fact, it probably happens quite rapidly after a certain point. Even an elite level athlete has a breaking point.
An example from another sport
In baseball, pitch count comes up a lot. Teams analyze their pitchers (mainly starters) with respect to their work load. That’s not just total pitches, but also the distribution of them (for example, did a whole bunch come in one inning?).
Why do they do this? Because they realize performance tends to drop dramatically after a certain point.
Similarly, every year there is the question of ace starters pitching on short rest in the playoffs. The numbers for when they do so are not very good.
By the traditional view of mental toughness, which is focused on simply doing one more repetition when stressed in some way (to include fatigue), these pitchers are mentally tough. When you consider, though, all of the things mentioned above that are part of the equation (capacity for emotional understanding, energy maintenance, information input, work output), clearly they’re lacking. They’re not “tough enough” to execute at their full capability because of fatigue.
Putting it together
Mental toughness isn’t about doing one more repetition. It’s about the ability to do one more good repetition. If you lack the fitness, or don’t get sufficient rest, you just won’t be able to do it. This is why proper conditioning combined with appropriate recovery are so important.
I think there’s also another aspect to mental toughness which is more emotional, though still linked to the fitness/fatigue aspect. That’s a topic for another post, though.