Boss Roy Keane says the squad's two-day visit to the Colchester Garrison will stand them in good stead for the season ahead. The Blues were put through their paces by the 7th Parachute Regiment Royal Horse Artillery.
The players and management completed an assault course, initiative tests, built an overnight shelter and shot live ammunition before marching to the barracks this morning for combat simulation and endurance tests.
Keane told the club site: "We wanted to take the players out of the comfort zone and that was certainly achieved.
"You are pushing them mentally and physically, and it showed the importance of teamwork, discipline and leadership.
"It was hard work and the players are tired but I think they enjoyed it and their attitude was spot on all the way through.
"We have a long hard season in front of us and there will be setbacks along the way but what we learned about the group in the two days will stand us in good stead for that.
"The staff were great and really pushed us. It gave us an insight into their life. It was also a reminder of how lucky we are to get well paid for doing a job we love."
Elsewhere, released striker Dean Bowditch has completed his move to Yeovil, signing a one-year deal. Bowditch, 23, joins ex-Blue George O'Callaghan at Huish Park.