On a Sunday morning at the foot of Hon Vuon Mountain, groups of runners busily laced up their trail shoes, adjusted their trekking poles and hydration vests before setting off along steep, rocky paths still glistening with morning dew. Instead of pounding the familiar flat streets, they head into the mountains and forests to challenge themselves. Trail running is rapidly gaining popularity in Hue, attracting a growing number of enthusiasts, from young adults to runners well into their 60s.