How to train for a Half Marathon: Why your first 10K matters more than you think

Ask any first-time half marathon runner what worries them most, and the answer is almost always the same: the number. Twenty-one kilometres sounds like something you need to be worried about, so the whole training plan gets built around surviving it. Long runs get scheduled around it. Rest days get planned keeping that distance in mind. Most of the mental energy goes into that final stretch.

What usually gets ignored is the 10 Km sitting quietly in the middle of that same plan, and that oversight is worth correcting well before race day. Anyone training for the Times Internet Half Marathon would do well to treat that middle distance as seriously as the finish line itself, because the gap between finishing strong and limping through the last five kilometres is rarely decided in the final stretch. It's decided weeks earlier.

The middle distance nobody takes seriously

A 5K is short enough to push through on willpower alone. A half marathon is long enough that pacing simply isn't optional. The 10 Km sits awkwardly in between, long enough to expose bad habits, short enough that most runners don't take it seriously.


This is usually where the mistakes begin. Going out too fast because the legs still feel fresh. Skipping water because the distance doesn't feel long enough to need it. Cutting the cool-down short because it "wasn't that hard." None of it feels costly at 10 Km. At 21 Km, it adds up fast, right when there's no energy left to fix it.

Pacing discipline doesn't start on race day

Most runners assume pacing is something to figure out closer to the race. In practice, pacing habits are set much earlier, and a 10 Km run is usually the first real test of that discipline under actual fatigue, not theory.

A runner who learns to hold back in the opening two kilometres of a 10K tends to carry that same restraint into a half marathon almost without thinking about it. One who doesn't usually repeats the mistake later, only this time it costs them around the 15K mark, with six kilometres still to go and nothing left in reserve.

A few habits worth building early

Some of this comes down to small choices made weeks before race day. Start slower than feels necessary, and trust that pace even when your legs want to go faster. Practise eating and drinking water during the run, even if the distance feels too short to need it. Run the last two kilometres of a 10 Km with real focus, instead of just getting through them. And take rest after a 10 Km seriously, the same way you would after a longer run. These small habits are often what separate runners who keep improving from those who keep getting hurt.

None of it feels less in the moment. Its value only shows up later, somewhere past the halfway mark of a half marathon, when it's too late to build the habit from scratch.

The real test isn't the distance

A half marathon rarely falls apart because someone couldn't physically cover 21 kilometres. It falls apart because pacing, fuelling, or patience broke down earlier, and the 10K stretch was the last real chance to catch it. For anyone signed up for the Times Internet Half Marathon, that's the training window worth protecting, not the final few kilometres everyone worries about instead.

The most useful shift for a first-time half marathon runner isn't running longer, sooner. It's running the middle distance with the same seriousness as the finish line. The kilometres at the start quietly decide how the ones at the end will feel.

If you're building toward that first big race, the Times Internet Half Marathon is a good one to train for. Register now and give yourself the time to get the middle distance right. The training plan can only begin once the race is actually on the calendar

Register now for the Times Internet Half Marathon.