I am big fan of a basic sun-salutation series from yoga, especially as this can be done in a simple 2 square yard (3′ by 6′) area, and really doesn’t involve any crazy, difficult or unfamiliar movements.
Extend arms overhead, forward FOLD (hinging from hips), half forward bend (engaging hamstrings), forward fold, step back into LUNGE, step back other foot into PLANK, lower and HOVER, release to floor, lift head / press shoulders off ground COBRA (how high depends on client capabilities), release and press hips back over heels CHILD’s (forehead to floor arms extended out), lift tailbone towards sky in DOWNDOG or inverted “V”, step up first foot between hands in LUNGE, step up other foot and FOLD (enjoy the stretch), reverse swan up to stand (I teach my clients to hinge from the hip, using the hamstrings to lift the upper body, engaging the muscles of the core to stabilize the spine). Repeat (be sure to switch which leg goes back first on each repetition).
This is a very easy to learn and effective full-body exercise program especially when coordinated with the breath. It can be completed slowly, holding each pose for several breath cycles to work on strength and endurance, or complete several cycles (20 to 40) in rapid succession for an aerobic workout.
Its also a great from of moving meditation… and don’t think just because its based on yoga, that its not for men. I’ve taught this series to plenty of soldiers and to mixed martial artists.