People often assume ultrarunning is all about physical endurance. They see the distance, the elevation, the weather, and the hours on your feet, and naturally conclude that the strongest legs will always win. The longer I spend in this sport, the more I realise that’s rarely the case. Fitness gets you to the start line, but your mind determines how far you go once the race begins.

This weekend was another reminder of that.

I set out to complete a six-hour training run on an exposed out-and-back course. There was no shade to hide beneath, no winding woodland trails to break up the scenery, just a long stretch of path disappearing into the distance under an unforgiving summer sun. By the middle of the day, the temperature had climbed to 28°C, and every turnaround meant heading straight back into the same conditions I’d just come through.

Physically, it was demanding. Mentally, it became something entirely different.

What fascinates me about endurance running is the conversation that takes place inside your head. It doesn’t happen all at once. In fact, it starts almost as soon as you leave the start line. At first, the voice is encouraging. You feel fresh, your pace feels comfortable, and everything seems possible. Then, almost without noticing, that voice begins to change.

As the heat builds and fatigue slowly creeps in, your mind starts looking for reasons to make life easier. It suggests slowing down, taking a longer walk break, or convincing yourself that you’ve already done enough for the day. It tells you that nobody would blame you for stopping early because, after all, it’s hot, you’ve already covered a decent distance, and there’s always another run next weekend.

What’s interesting is that your brain isn’t trying to sabotage you. It’s trying to protect you. Human beings are wired to seek comfort and conserve energy. Thousands of years ago, that instinct helped us survive. Today, it often becomes the very thing that holds us back from discovering what we’re actually capable of.

That’s why I think ultrarunning is one of the greatest teachers of mental resilience. It forces you to recognise the difference between genuine physical limitation and simple discomfort. Those two things are not the same. Discomfort can be negotiated with. It comes and goes. It tells stories that aren’t always true. Real physical limits deserve respect, but discomfort often disappears if you’re willing to stay with it for a little longer.

As the hours passed, I realised I wasn’t really competing against the distance or the heat. Those conditions were the same for everyone. My real challenge was deciding which voice I was going to listen to. The one searching for comfort, or the one reminding me why I’d chosen to be there in the first place.

There came a point where I stopped wishing the weather would change. I stopped hoping for clouds that weren’t coming or a cool breeze that never arrived. Accepting the conditions instead of fighting them was surprisingly liberating. Once I accepted that it was going to be hot for the rest of the run, my focus shifted away from complaining internally and towards managing the situation. Drink regularly. Stay on top of nutrition. Keep moving. Break the run down into manageable sections and deal only with the piece of trail directly in front of me.

It’s amazing how much easier difficult things become when you stop arguing with reality.

People often ask how anyone runs fifty kilometres, but I don’t think anyone really runs fifty kilometres. You run the next hundred metres, then the next, and then the next again. You repeat thousands of small decisions until eventually the distance takes care of itself. Endurance isn’t built through one heroic effort. It’s built through countless ordinary decisions to keep going.

By the time six hours had passed, I’d covered 52 kilometres. It wasn’t the fastest 50k I’ve ever completed, nor was it supposed to be. What made it satisfying wasn’t the number on my watch; it was knowing I’d stayed committed to the process despite the conditions. The heat had tested me, but it had also taught me something.

Mental toughness isn’t about pretending things don’t hurt. It isn’t about ignoring discomfort or never doubting yourself. Those doubts will always be there. The strongest athletes aren’t the ones who never hear the voice telling them to stop—they’re the ones who hear it, acknowledge it, and decide it doesn’t get to make the final decision.

That’s a lesson that reaches far beyond running.

Life rarely gives us perfect conditions. We all face days when the heat feels relentless, when progress is slow, and when the easier option is to quit. The circumstances may be different, but the conversation inside our heads is remarkably similar. Every challenge presents the same choice: listen to the voice that seeks comfort, or listen to the one that believes growth lies just beyond it.

This run reminded me that the longest conversation we’ll ever have is with ourselves. It also reminded me that we get to choose which voice has the final word.

Mike.

UltraEnduranceLab