The American College of Sports Medicine has published its 2026 Fitness Index, ranking the 100 healthiest US cities based on health behaviours, outcomes and infrastructure. Outside Online has put its own spin on the top ten, focusing on how visitors can actually get active in each one — and several of them double as brilliant city-break destinations for travellers who'd rather run a trail than a treadmill.

Boston stands out for car-free exploring. The Charles River paths and the Freedom Trail make classic running routes, Paddle Boston rents kayaks and paddleboards, and the new Boston Boundless Trail — a 91-mile hiking loop launched last June — links more than 100 green spaces around the city's perimeter. Revere Beach is a quick ride away on public transport.

Madison, Wisconsin, surprises many first-timers. Surrounded by five lakes covering 15,000 acres, it's one of only five platinum-level bike cities in the country, and the 6.5-mile Lake Wingra Loop passes ancient Native American effigy mounds. In winter, parks like Elver groom trails for cross-country skiing.

Atlanta, the "City in a Forest," has 343 parks and 125 miles of multi-use trails, with nearly 17 miles of the ambitious Atlanta Beltline opening this summer ahead of the World Cup. Runners make up almost a quarter of the population here, and the July 4th Peachtree Road Race is the world's largest 10K.

San Francisco earned the index's top walk score — those steep hills do the work for you — plus car-free paths in Golden Gate Park, surfing at Ocean Beach, and the legendary Dipsea trail run in nearby Marin County. Denver packs 250 parks and 850 miles of trails into the city, with ski slopes and Red Rocks' brutal 200 amphitheater stairs within easy reach. Seattle, second overall for personal health, adds cold plunges off the new Waterfront Park and wood-fired floating saunas on Lake Union. Minneapolis tops the bike-score category thanks to its 51-mile Grand Rounds loop past Minnehaha Falls, and Washington DC has more trail miles per resident than any American city — a morning jog along the National Mall doubles as sightseeing.

The appeal for travellers is obvious: these are cities where you can skip the gym entirely. Bike-share systems are now nearly everywhere in the US, park yoga classes and casual 5Ks are easy to find, and a growing share of urban spending is going into walking and cycling infrastructure. If your ideal holiday mixes sightseeing with a sunrise run or a paddle, any of these ten makes a strong case.