the woman who "hosts" these is jillian michaels from the biggest loser series. i have her cardio kickbox dvd and two of the strength training ones. there are also two more strength training ones that are even higher intensity than the two that i have.
man, this woman is kicking my butt. ive done the kickboxing one 4 times and the strength training ones once each and have yet to not take a break during them. each workout is 30min so its super convienent to fit in when pressed for time and all of them are intense enough that i feel like i got a serious workout in that time.
jillian is a little annoying at times, she giggles randomly but the dvds are the best that ive found and ive tried several. i highly recommend this series for anyone looking for something to jazz up their routien.