Mental fitness
Composure is a trainable skill.
Athletes already accept that speed, strength, and mobility respond to training. Mental fitness works the same way: small, repeated practice changes how you respond under pressure. It isn't a personality trait and it isn't something you either have or don't.

The skills
Four things you're actually training
Attention
Choosing what to focus on, noticing when you've drifted, and coming back without a fight.
Activation
Reading your own arousal level and nudging it up or down to match the moment.
Recovery
Letting your nervous system down-shift after hard efforts so the next day starts clean.
Confidence
Building belief from evidence you collect, not from how the last competition felt.
Mental fitness vs. mental health
Related, but not the same thing
Mental fitness is performance training. Mental health is your wellbeing, and sometimes it needs professional care. 26 Strong focuses on training, and it never pretends to replace treatment.
If things feel heavier than training
Persistent low mood, anxiety that won't settle, or thoughts of harming yourself are signals to talk to a professional — not signals to train harder.