RMRR Spring Marathon Training Series #1

Lace up your shoes for the RMRR Spring Marathon Training Series #1, a welcoming and supported event designed to help runners prepare for their spring marathons. Taking place on March 29, 2026, in Thornton, Colorado, this low-cost, low-key series offers both 10-mile and 20-mile distances, providing an excellent opportunity to fine-tune your pace, nutrition, and race strategy in a timed and encouraging environment. The race kicks off at 8 AM from the Platte River Trailhead Park at 88th and Colorado, utilizing scenic out-and-back courses along the Platte River Trail.

The Rocky Mountain Road Runners (RMRR) are well-regarded for providing consistent training opportunities for runners of all abilities. Aid stations are well-stocked with water, sports drinks, and gels to keep you fueled throughout your run. This event is part of a two-race series, with another training race scheduled for April 11, 2026, allowing for progressive training. Typical race day conditions in late March in Thornton often bring highs around 64°F and lows around 33°F, with a low 6% chance of precipitation, creating generally favorable running weather.

Whether you're targeting a major event like the Boston or Colfax Marathon, or simply looking for a supported long run, the RMRR Spring Marathon Training Series #1 offers a valuable experience. RMRR members can enjoy a 50% discount on registration, making it an even more accessible option. Please note that for the safety of all participants, dogs and running strollers are not permitted on the course.