How to Pace and Execute a Marathon

Get Fast Podcast, Ep 257, with Gerard and Jordan Donnelly

Start conservatively and aim for an even or negative split, where your second half is the same as or faster than your first. Build your race plan around your current form and the course, not the time you want. Gerard says you very rarely run a personal best when you start strong and fade.

What did the Melbourne Marathon weekend show?

On this weekend, five TriVelo athletes ran a marathon and three ran a half marathon. Gerard also clicked through the 5K splits of runners he doesn't coach. The majority were slower in the second half.

To be fair, the second half was harder. After the last turnaround came 40 to 50 minutes into a headwind, the heat was rising and the finish was hillier. That didn't stop the TriVelo athletes from running negative splits. In the half marathon, three athletes finished between 1:30 and 1:33, all with negative splits. Two of them ran 10 to 15 seconds per kilometre faster in the second half.

Can you start a marathon too conservatively?

Yes, but Gerard says it still gives you the best outcome. Starting conservatively gives you room to move. If you hold back a little too much, you might lose a minute. If you go out too hard, you might lose 10.

Some athletes finish and say they had too much left. Jordan says that feeling isn't real. You feel strong at the end because you paced well. If you'd gone out harder, you couldn't have finished that way. In all his years coaching endurance sport, Gerard could count on one hand the athletes who told him they should have gone harder.

Runners who start conservatively also enjoy the race more. They spend the last kilometres passing people instead of being passed.

What happens when you go out too hard?

One athlete sent the Donnellys a message after the race. At her first marathon, a previous coach told her to run the first half as hard as she could. She faded badly, the 3:40 pace group passed her, and the coach told her she wasn't built for marathons. It took her four years to try again.

This time she passed the 3:40 group, and nobody passed her in the last 6 km. She ran a five-minute personal best, three weeks after an Ironman.

Jordan also tells the story of a friend he doesn't coach. His goal was 3:30, with a fallback of under four hours. He started well faster than 3:30 pace and finished in 3:54. He said it was the hardest thing he'd ever done.

Gerard's rule of thumb: if you slow by more than 30 seconds per kilometre, you've blown up. That soon becomes a minute per kilometre, and walking costs about two minutes per kilometre. You can finish 30 or 40 minutes slower than you wanted.

How do you set a realistic race plan?

Be honest about your current form. Gerard describes his conversation with a first-time marathoner who wanted to break four hours. They agreed he was about a 4:05 runner. They went through the scenarios together:

• 5:40 per kilometre would give about 3:58, but carried the risk of a blowup to 4:10 or 4:15.
• 5:45 to 5:50 per kilometre would give about 4:04 or 4:05.

Gerard also pointed out the forecast: a northerly, meaning a headwind of around 25 km/h from Elwood all the way to the finish, plus the hills near the end. The choice was the athlete's, as long as he accepted the consequences.

A few seconds per kilometre doesn't sound like much. Over a marathon, five or 10 seconds per kilometre adds up to minutes.

When should you decide whether to push on?

Not in the first 5 km. You've tapered, so you'll feel fresh early whatever pace you run. Gerard says the decision belongs around 25 to 30 km, based on how you're coping with your pace.

The first-time marathoner ran 5:45 to 5:50 per kilometre confidently until the mid-30s. Then a stitch, tiredness and the coming headwind told him to hang on rather than speed up. Gerard was as proud of that run as of the negative splits, because the athlete knew every scenario before he started.

Have backup plans too. Know what you'll do if you drop a cup, miss your special needs bag or lose your gels.

What counts as a good split?

A negative split doesn't mean running the second half three minutes faster. It means running the same time or slightly quicker. On a course with a harder second half, finishing within a minute to a minute and a half of your first half is still well executed. Often you're lifting your effort just to hold your pace.

Don't speed up in a tailwind to bank time. On the bike, a tailwind pushes you along at low effort. On the run, going faster than your pace still costs you, tailwind or not.

Why is holding back so hard?

Everyone knows not to go out too hard, but excitement takes over. Jordan says athletes promise to run their first kilometre 15 seconds slower than target pace, then call afterwards to admit it wasn't their slowest. Letting thousands of runners go past you early takes discipline. Gerard says that discipline at the start is the challenge to focus on.

Some goals take time. Gerard recalls an athlete, Daniel, who tried to break three hours for three years. He ran 3:00:30, 3:01:30 and 3:02 before running 2:58 at Melbourne.

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