The Eagleman Half Run: 13.1 Flat Miles, Zero Shade, Blazing Sun

The course

21.1 km, completely flat, on a double out-and-back, finishing at Gerry Boyle Park in Cambridge. Only one shaded stretch worth mentioning, short, near Lovers Lane, about halfway through the loop. Everywhere else: full sun.

The double out-and-back format has an upside: you see your competitors, you see your teammates, and you can mentally break the race into four 5 km blocks. Use it.

The problem isn't the course, it's the clock

For most age-groupers, the run falls between 10 a.m. and 1 p.m. In mid-June on the Chesapeake, that means average highs of 30 °C with high humidity; in 2008 a heat index of up to 43 °C was recorded. Race reports call the Eagleman run heat 'notorious', and they're not exaggerating.

On a dead-flat course there's no elevation excuse: if you slow down, it's the heat. And humid heat shows no mercy to anyone who goes out at their cool-conditions half marathon pace.

Pacing: negative split or nothing

The mandatory strategy on this course, cited by multiple sources:

• First 5 km well below goal pace. You come out of T2 with bike legs and a body that's already hot: give your system time to settle.
• Km 5-15: race pace, if your body responds. Watch your heart rate: if it drifts upward at the same pace, slow down immediately.
• Last 6 km: push only if you've managed it well. This is where you pick off people in bunches, because the road is full of athletes who went out too hard.

Accept a simple idea: your potential time in these conditions is slower than your potential time in April. Those who don't accept it end up walking.

Cooling: a protocol, not improvisation

At every aid station, in sequence:

1. Ice in your cap and, if your tri suit allows it, in the suit (chest and back). 2. Water on your body: head, back of the neck, thighs. Not just to drink. 3. Drink at every aid station, regular electrolytes, not just plain water.

Do it from the start, from the first aid station, not when you feel cooked: by then you're already twenty minutes behind on your thermal state. Test the protocol in training in the weeks before, along with heat acclimation (2-3 weeks of progressive exposure).

Note: the exact location and supplies at the aid stations are not published in the sources consulted; check the official Athlete Guide before the race.

What to train between now and race day

• Runs during the hot hours: not all of them, but a few key sessions at midday, to get your head and body used to it.
• Bricks after long flat rides in aero: the legs you get off 90 km of steady riding in position are different from those after a rolling route.
• Test the ice/water protocol: find out in advance whether ice in your suit bothers you or saves you.

The decision to make

Set two paces, not one: the 'normal day' pace and the 'furnace day' pace, 15-25 seconds per km slower. On race morning, based on the actual temperature and humidity, choose which of the two to use for the first 10 km. It's a decision to make cold, before the start: at km 8, under the sun, you won't be making any clear-headed decisions.