Jack McCallister rarely lets his guard down.

It's a curse that followed the former Marine lieutenant home from the Vietnam War. Although it took him 20 years to admit it, McCallister, 65, came home from the war with post-traumatic stress disorder. He's always on edge, easily startled and often depressed.

One of the few times McCallister has found when he feels comfortable letting his mind and body unwind is when he's practicing yoga. He is among the first participants in a new program a local yoga instructor is offering free to combat veterans.

Martha McQuaid is an instructor at Spirit House Yoga, 5107 N Shartel. She is offering the iRest form of yoga to veterans at 4 p.m. Mondays.