The riders were back on courses in Edinburgh, although the competition has adapted to accommodate social distancing.
The action has moved away from regular racing and is using a time trial format instead.
It was the second event that Army Mountain Biking have held since being authorised to return after lockdown.
"It's absolutely fantastic to be back," says Captain Will Matthews, who is the manager of the team.
"Since lockdown, we've all been training hard and doing bits and pieces in the background.
"This is absolutely what this series is about – having fun and inspiring soldiers to cycle."
Warrant Officer James Cooper, Secretary of the Army Cross-Country Mountain Biking Series, encouraged more people to get involved with the sport.
"Today is our second race of the year," he said.
"The aim of the mountain biking series is really to introduce as many novice riders as possible to come and test themselves against a course that's challenging but becomes slightly more difficult with speed."
The event was held in Edinburgh's Pentland Hills – a rare return to Scotland for the riders.
Major Simon Greenman of 3 RIFLES said: "It's the first time it's been in Scotland for quite a while.
"It's good to get people up here in the hills of Edinburgh rather than the flats of southern England."