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.
That is the best movement series that I can recommend for clients in and outside of the gym. It focuses on unification of the posterior line, decompression, and stabilization of the spine through large incorporated exercises. They are all large movements and do not require equipment. They have a new DVD and digital download.
Hope this helps,
I really love body-weight exercises for hotel rooms as well as exercises that can be used with a resistance band (which is easy to travel with).
Here are a few good moves for the whole body (which of course you would need to deem appropriate for your clients or modify if needed):
You could do a circuit of one-minute exercises, and repeat 3x:
Pushups (on toes or knees)
Squats/Squat Jumps (modify if needed)
Planks (all kinds–front planks, side planks)
Burpees/Jumping Jacks (modified to low-impact if necessary)
Hope this helps and good luck!