Clients are always looking for a full-body exercise. The Burpee,aka Squat Thrust...
drop to the floor, kick your legs back to a plank, pull legs back to start and jump up, throwing arms to the sky.
...is a great example that hits most major muscle areas - butt, legs, arms, abs... Wondering why it has such a yucky sounding name? Try 15 successively and quickly to begin a workout. Ping me with your moment of brilliance.
Take it to a platinum level, adding a Bosu for an additional core stabilization challenge.
Work to hold the Bosu still in hands (dome side down) as you kick back and return to squat. Keep feet & knees together to add an inner thigh benefit & allow abs to contribute more to bringing the legs back in. Finally, press the Bosu over your head. 1 full breath (inhale/exhale) per burpee: try to inhale as you drop down & kick out & quickly exhale every last drop of air while squeezing your abs as you bring the legs in & return to standing. (Add 1 breath per pushup - inhale down, exhale up - if you do these in between).
Alternatively you can use light hand weights instead of the Bosu. Remember start w/ low weight - 5lbs in each hand is perfect - get those abs fired before you ramp up to 10, then 15lbs so you don't throw your back out pressing back up. (The weights are much heavier as you pass through the many planes of this exercise does w/ speed).