The Campeche Bike Leg: 90 Flat Kilometers Where the Half Marathon Is Won (or Lost)

The course in two lines

90 km over two laps along the Merida Highway, closed to traffic. Official elevation gain around 230 m, altitude between 79 and 100 m above sea level. No real climbs, no technical descents. It's a time-trial course: aero position, steady power, brain switched on.

On paper it's one of the fastest routes on the Mexican circuit: the organizer itself promotes it as a PR course. Always check the updated version on the official website before race day, because the current course sheet comes from the 2025 athlete guide.

The wind: the only real variable

On a flat, straight road the wind decides everything. Several race reports describe conditions that vary between the out and back sections: stretches with a headwind, crosswind sections, tailwind sections. The classic trap is the tailwind segment: you're cruising at 42 km/h with no effort, you feel like a pro, you bump up the watts. Then you turn around and the bill comes due.

What to do, in practice:

• Race by power or by calibrated feel, not by speed. If you use a power meter, set a target and stick to it with the wind at your back and in your face.
• If you don't have a power meter, use heart rate with a hard ceiling and accept that your speed will fluctuate.
• Since it's two laps, use the first one to figure out where the wind is coming from and where you can recover. The second lap is where discipline pays off.

Heat and hydration starting on the bike

Average highs hover around 32 °C with high humidity. On the bike, the airflow cools you down and fools you: you sweat a ton without noticing. The bike leg is where you build (or destroy) your half marathon. Drink from the first few kilometers—don't wait until you're thirsty.

There are about 6 aid stations, one every 11 km (at miles 10, 15.5, 23, 31, 38 and 45 according to the guide). Plan how many bottle grabs you'll need and where you'll take them.

The bottle detail: test it beforehand

A practical note from a 2018 race report: the bottles handed out on course (tapered Gatorade format) didn't fit standard bottle cages. Two solutions:

1. Mount universal bottle cages and verify at home that they hold a bottle shaped differently from yours. 2. Start with your own bottles and refill at aid stations by pouring, accepting a few extra seconds.

Whichever option you choose, test it in training. Losing a bottle in 35 °C feels-like conditions is not a minor detail.

Cutoffs and numbers to know

According to the 2025 guide: first lap (50 km) must be completed by 11:25; bike leg within 5h30 of the last swim start. For those aiming to finish, these are manageable margins, but only if T1 goes smoothly and the swim doesn't drag on.

For reference, rough (unofficial) projections put bike splits from 3:15 for a relaxed finisher down to 2:18 for the top age groupers. On this course, aerodynamics and consistency make the difference, not peak watts.

What to do between now and race day

• Train long blocks in the aero position: 2-3 hours without coming off the aerobars, because there are no climbs here to force a position change.
• Rehearse your full hydration strategy on a long ride: quantities, frequency, simulated aid-station pours.
• Decide your race gearing: on a course like this you need a drivetrain that lets you spin a smooth cadence at high speed, not climbing gears.
• Choose and test universal bottle cages at least three weeks out.

The Campeche bike leg won't hurt you with gradients. It will hurt you if you come out of position, if you chase speed with a tailwind, or if you roll into T2 dehydrated. Three avoidable mistakes, all three free to avoid.