i first and foremost want to say that i have been doing these for quite some time, so you might have to ease into it if... dont say i didnt warn you (*fun fact- wish someone had warned me about easing into the 100 push up challenge that @MyTrainerBob put out last week on twitter. arms have never been so sore.... and apparently i didnt learn from the first time, i did a 300 challenge from bob... 100 push ups, 100 sit ups, 100 squats. ouch).
power 8's consist of pretty much what it sounds like, different exercises with 8 reps of each exercise. a normal routine for me looks like this:
8 x .25 mile sprints on the treadmill
8 x 25 crunches
8 x 5 (each side) tea pots with 15 lb weight
8 x 50 jump rope
8 mile bike on level 8
run one mile on speed 8.0
now as you can see, that can definitely be changed up to tailor to what you enjoy doing at the gym, as well as different distances and reps (could even do power 6's or power 10's.... the possibilities are endless really).
i usually find a treadmill that is not near a lot of people (a plus to working the overnight shifts, i can go to the gym during times where there are not a ton of people around to stare and make funny faces at me). sprint .25 miles (i usually start off about 8.6 and go up after i get warmed up), get off and do 25 crunches, get back on the treadmill and sprint .25 miles, off for 25 more crunches.... repeat 8x. you get the idea. and you see why people would probably look at me funny.
"tea pots" is what i call putting a dumb bell in one hand hanging down to one side, while placing my other hand on the back of my head. then you bend down towards the side that the dumb bell is, and back up (thats one rep). kinda makes you look like a tea pot. makes you want to sing "be our guest!" from beauty and the beast! ok, thats probably just me.
the rest is pretty self explanatory i think... i try to do a power workout at least twice a week. im thinking ill start trying power 10's sometime soon, once my body adjusts to 8's. still havent brought myself to add in a pool workout, but that could easily be added to the mix.