Nothing jumpstarts your summer fitness regimen like getting a competition on your calendar. Chances are, you’ll find a running or cycling race happening every weekend from now through October in the Centennial State while athletes take advantage of this beautifully balmy weather. Whether you’re looking to aim high—in both elevation and challenge—or you just want to experience that elusive runner’s high everyone keeps talking about, here are a few comps worthy of a spot on this summer’s bucket list.

FoCo Fondo

  • When: July 23
  • Where: Fort Collins

Long-time bike enthusiasts and Fort Collins locals Whitney and Zack Allison are setting a new standard for inclusivity in the gravel racing realm. With every passing year this feel-good Fondo welcomes more and more riders to the starting line with the help of BIPOC scholarships; non-binary and para race categories; and childcare during the event. New in 2023: the leadership program, with representatives from four typically underrepresented groups in the cycling world: BIPOC, para, women, and non-binary.

The FoCo Fondo offers four routes, starting with the non-competitive 12-mile ride, perfect for newbies and more casual cyclists just giving gravel a go. The Dare You route jumps up to 32 miles, then 53 for the Double Dog Dare You—and finally the 118-mile Triple Dog Dare You. The Dare You trio all weave through farm country north of Fort Collins; the Triple tacks on some 7,500 feet of climbing, meandering through the mountains northeast of Red Feather Lakes. If you can convince your quads not to quit, there are some tempting rewards on the table like a legendary bolo tie, awarded to men who complete the 118-mile course in under seven hours and women and non-binary competitors who finish in under 7.5 hours. Whether you’re blessed with a bolo or not, all routes end at New Belgium Brewing, and beer isn’t such a bad consolation prize. Online registration closes July 20, but same-day registration is available.

Georgetown to Idaho Springs Half Marathon

  • When: Aug. 12
  • Where: Georgetown

We could tell you all about this half marathon’s gorgeous route leading you around Georgetown Lake and past Bridal Veil Falls, but there’s something even more enticing—and rare—about this iconic race: It actually loses elevation. The gentle, rolling course parallels Clear Creek and drops more than 1,400 vertical feet from start to finish—your legs can thank us later.

But don’t fret, this scenic half marathon still boasts plenty of challenging surprises, including a short uphill leg to finish in Idaho Springs. All paces are welcome but the course closes at noon, so run, walk, or crawl accordingly. Runners will park in Idaho Springs and hop a shuttle to the start line. Registration ends August 10.

Breck Epic

The Breck Epic. Photo by Eddie Clark Media
  • When: Aug. 13–18
  • Where: Breckenridge

The most challenging aspect of this six-day stage race is not the 25 to 42 miles you’ll cover each day—it’s resisting the urge to pull over every five minutes to snap a photo of your high-elevation surroundings. You’ll ride some of the world’s most iconic singletrack around Breckenridge’s backcountry and tackle a (literally) breathtaking 3,700 to 7,000 feet of climbing per day. So although you may be tempted to tap the brakes for a selfie (or to suck wind), remember you’ve still got dozens of miles to pedal and, as was the case in 2022, the occasional thunderstorm to outrun.

You’ll earn some serious mountain cred if you can do the whole race solo, but there’s also duo and relay categories—because suffering with a friend is way more fun. Yes, there are hardened pros that take the podium but also a strong contingent of hard-charging and harder-partying amateur riders. The event is capped at 500 riders (sorry, no e-bikes). Registration is available right up until race start, but this is one you probably want to plan for in advance.


  • When: Sept. 9
  • Where: Nederland

Launched in 1982, the Ned*Ned is one of trail running’s pioneer enterprises, and somehow its laid-back grassroots vibe has managed to stay intact throughout all these decades. The crowd is competitive but fun-loving (even when Mother Nature makes it more of a mud run than a trail run, like last year), and, in spite of the event’s growing fame, it never seems to get cramped. Once you hit the trails, there’s plenty of space to stretch your strides.

People don costumes and bring their pups for the out-and-back 5K through historic downtown Ned, while the competition is a bit stiffer for the 10K and half marathon—where dogs and walkers are not allowed and runners tackle some of the most scenic, wildflower-framed singletrack in the area. The route ends and begins at TEENS, Inc., the youth development nonprofit you’ll support with your registration fee. Day-of registration is available from 7:15 to 7:45 a.m.

The Gunni Grinder

  • When: Sept. 9
  • Where: Gunnison

We told you gravel biking was the next big thing, and the burgeoning Gunni Grinder is proof that Colorado’s dirt-loving diehards are here to stay. The Grinder features three races through Gunnison County—including a 120-miler that sends cyclists into the Western Slope’s remote high desert on rustic dirt roads. Last year, organizers added 60- and 30-mile options. The 30 offers an appealing out-and-back route for newbies that doubles back at the high point, meaning you can kick it into cruise control for the second half. Competitors in the 120- and 60-mile courses can also relish a downhill ending—after they’ve conquered the steep and unforgiving climbs that come before it, of course. Register early for reduced prices or make a game-time decision on the morning of the big day.

Colorado Springs Marathon, Half Marathon, 10K, and 5K

  • When: Sept. 30
  • Where: Colorado Springs

This pavement-pounding marathon has been selling out the last two years, so you’ll need to move quickly if you want to be a part of its 10th anniversary celebration. In honor of the milestone, the Colorado Springs Marathon is ramping up this year’s race to have more running revelry than year’s past (think: bigger bling for finishers, long-sleeve tech shirts for participants, and even a virtual race for folks following along at home).

The course is as much for history buffs as it is for those who relish a runner’s high: The full and half marathon courses head out from downtown Colorado Springs and circle the U.S. Olympic and Paralympic Museum before hitting numerous historic sites along the paved and packed gravel Greenway Trail. You’ll coast along Monument Creek to the north—only gaining about 750 feet in elevation—before doubling back on the same path to finish at the starting point, the Pioneer Museum. Registration available until sold out.


  • When: Oct. 8
  • Where: Boulder

Despite being just three years old, this breakout Boulder race is already one of the most popular running series in the state. Formerly the Boulder Backroads Marathon, Boulderthon has tripled in size since it launched in 2021, selling out last year. Organizers doubled the capacity this year, so expect to be surrounded by 8,000 other athletes between the marathon, half marathon, 10K, 5K, and kids’ routes.

All courses start and finish at the Pearl Street Mall in downtown Boulder, with flowy sections through the foothills in between. See the Flatirons edged with gilded aspens before snaking through the charming communities of Gunbarrel and Niwot. Boston hopefuls ought to bring their A-games: The course gains just over 1,400 feet in elevation. Expect an all-out, endorphins-fueled fete at the finish—and a frothy beer. Registration available until sold out.