Ask most runners what a good training week looks like, and they'll tell you how far they ran.
That's understandable, but distance doesn't tell the full story.
Training isn't just how far you run. It's frequency, intensity, recovery, stress, and context.
They all matter.
10km run up a mountain is not the same as 10km run on the flat.
5km run into a strong headwind or on trails is nothing like 5km run on a calm track.
20km at altitude costs more than 20km at sea level.
It's the same distance, but it's not the same training. Your body doesn't know distance; it knows stress.
This is the game.
Apply enough stress for your body to adapt and get stronger.
Too little and you won't progress. Too much and things start to break down. You peak too early or get injured. You lose consistency.
Training by time helps you hit the right dose more often.
Here's why it works
Time self-corrects.
When conditions are harder, you cover less distance, and when conditions are easier, you cover more. The stress stays close to the target, which keeps training sustainable.
Distance pushes runners into bad decisions.
The tired runner late in a run, picking up the pace. Not because they've found a second wind, but because they just want to hit their prescribed distance and go home.
10km is 10km. The distance doesn't care how you're feeling, and that extra push adds fatigue without benefit.
When training is time-based, there's nothing to chase. Tired? Slow down a bit. Feeling good? Flow.
The work still gets done, and that's what matters most.
Distance has its place in race-specific sessions, time trials, testing.
But for most of your training, especially for athletes juggling work, family, and everything else, time is the better option.
It adapts to fatigue, weather, and terrain. And, you always know how long each session will take.
Most importantly, it protects consistency.
Always optimise for consistency. It's the ultimate performance enhancer.
