The Lima 70.3 Bike Leg: Flat on Paper, Decided by the Wind

The Course by the Numbers

90 km on a circuit of 3 laps of 30 km along the Costa Verde, between Chorrillos and Magdalena del Mar, on roads closed to traffic. The official elevation gain stated by the organizer is 1,527 feet, roughly 465 meters. Translation: a flat or gently rolling course with a couple of short kickers, no real climbs. The organizer describes it as flat and fast, which fits the geography of Lima's waterfront.

One important warning: third-party elevation profiles circulating online show much higher elevation gain. They contradict both the official number and the course descriptions. Trust the organizer's figure and plan your race for a fast course, not a hilly one.

The Real Opponent: The Pacific Wind

On a course with no climbs, the wind is what makes the difference. The ocean breeze on the Costa Verde can make the return stretch of each lap tough. The classic mistake is getting carried away by high speed on the tailwind section, burning watts, and then suffering into the headwind three times in a row.

The rule: manage power, not speed. If you race with a power meter, set a target and hold it both with a tailwind (even if it feels slow compared to what you could do) and into a headwind (even if your head unit shows a depressing speed). If you ride by feel or heart rate, apply the same principle: steady effort, variable speed.

Pacing Over Three Laps

The circuit format has upsides and traps. Upside: after the first lap you know every corner, every kicker, every wind-exposed stretch. Use the first lap as a controlled-intensity recon, then manage the next two with that knowledge.

Traps: traffic from athletes at very different speeds, crowded zones at the turnarounds, and the real risk of losing count of your laps. Count your laps yourself—don't rely only on the officials. Also watch out for unintentional drafting in sections where the field bunches up: on a 30 km circuit with hundreds of athletes, it happens.

Gearing and Position

With 465 m of elevation gain over 90 km, you don't need climber's gearing. Run a fast-course chainring setup and be ready to stay in the aero position for long stretches: that's where you gain time, especially into the wind. If you have deep-section wheels, keep in mind the coastal wind can also be a crosswind; if you're not stable with a very deep profile, go with a more conservative choice, especially up front.

What to Do in Training

• Long aero blocks into a headwind. Build rides into your prep with extended stretches at target power in the aero position, ideally into a real headwind. Holding your position without sitting up is a trainable skill.
• Loop-based pacing simulations. Train on a loop and repeat it: you learn to distribute effort over identical laps instead of point-to-point.
• Test your power target. On a half distance, the number one risk on a flat course is going out too hard on the bike and paying for it in the half marathon. Do at least one long bike+run simulation at race pace to validate your number.

The Decision to Make

Decide your power ceiling (or RPE ceiling) before the race and write it on your bar tape. In Lima, the bike leg isn't won on climbs that don't exist: it's lost chasing speed into a headwind. Whoever rolls into T2 with fresh legs on this course has a flat half marathon ahead to cash it all in.