Querétaro Marathon 2026 brings together 19,500 runners despite the rain

It rained on Querétaro that Sunday, and yet no one stepped back from the starting line. More than 19,500 people ran the 5, 10, 21, and 42-kilometer distances at the Querétaro Marathon 2026, supported by an operation of more than 2,500 personnel including security and emergency services. But the data that should really catch your attention isn't the total number of participants: it's that the half-marathon registered a record number of registrations, according to confirmation from the INDEREQ director. That's not coincidence or passing fad. It's a trend that's been setting the pulse of running in Mexico and Latin America, and if you run—or are thinking about starting—it's worth understanding why.

The context

The Querétaro Marathon is one of the most established urban races in Mexico's Bajío region, and like many city marathons, it offers a menu of distances so runners of all levels find their challenge: the 5K for beginners or those seeking speed, the 10K as a stepping stone, the 21K (half-marathon) as the "ambitious but achievable" distance, and the 42K for those who have graduated from the other three.

That record half-marathon figure isn't trivial. In recent years, the 21K has solidified globally as the favorite distance among recreational runners: it demands discipline and a serious training plan, but it doesn't force you to sacrifice entire months of social life or risk injury from excessive volume, as the full marathon does. It's the sweet spot between challenge and sustainability, and events like this confirm it with numbers.

The security operation—2,500 personnel—also tells a story: organizing a mass race in rainy conditions isn't trivial. Hydration, traffic control, medical care, and logistics for tent stations become more complex when the weather doesn't cooperate. That the race was completed successfully speaks to the organizational maturity that Mexico's racing calendar is reaching.

What the science says

Running in the rain changes the rules of the game, though not always for the worse. The science of thermoregulation teaches us that extreme heat is the true enemy of performance: heat acclimatization improves exercise capacity because the body learns to dissipate temperature more efficiently (Lorenzo et al., 2010). A rainy, cool day, paradoxically, can work in your favor for performance as long as hydration and electrolytes are managed well, because it reduces the accumulated thermal stress during long races like the 21K or 42K (Shirreffs & Sawka, 2011).

That said, rain brings its own challenge: wet feet, increased friction, and the risk of mild hypothermia in cold climates force you to rethink your race gear. As for pacing, evidence on half-marathons and marathons shows that recreational runners tend to start faster than sustainable and pay that price in the final kilometers (Nikolaidis et al., 2019; Cuk et al., 2024). Adverse weather conditions—like rain—amplify that mistake: when you don't see the sun or feel accumulated heat, it's easy to underestimate the real effort you're making.

What it means for you

If you ran in Querétaro or are about to run your first 21K in similar conditions, here are concrete ideas:

• Train your pacing, not your ego. Rain deceives: you feel fresh and start fast. Define your target pace before the race and respect it in the first kilometers, especially in the half-marathon, where starting mistakes are paid dearly at the 16K mark.
• Don't neglect hydration just because you don't sweat "visibly". With rain, we lose the visual reference of sweat, but fluid and electrolyte losses still occur. Follow your hydration plan as if it were hot.
• Invest in blister-prevention gear and technical clothing. Performance socks and vaseline in friction zones are non-negotiable in rainy races.
• If the 21K is your new goal, it makes sense. It's a distance that builds real endurance without the wear and tear of the full marathon—ideal for those looking to progress without risking their body or their life outside of running.

Rain didn't stop Querétaro. It shouldn't stop you either, as long as you train smart.

References

• "Heat acclimation improves exercise performance." — Lorenzo S, Halliwill JR, Sawka MN, J Appl Physiol 2010. https://pubmed.ncbi.nlm.nih.gov/20724560/
• "Fluid and electrolyte needs for training, competition, and recovery." — Shirreffs SM, Sawka MN, J Sports Sci 2011. https://pubmed.ncbi.nlm.nih.gov/22150427/
• "Pacing of Women and Men in Half-Marathon and Marathon Races." — Nikolaidis PT, Ćuk I, Knechtle B, Medicina (Kaunas) 2019. https://pubmed.ncbi.nlm.nih.gov/30646638/
• "Running Variability in Marathon-Evaluation of the Pacing Variables." — Cuk I, Markovic S, Weiss K, Medicina (Kaunas) 2024. https://pubmed.ncbi.nlm.nih.gov/38399506/