Warning! Warning! This swimming workout is not for the faint of heart, but if you're looking for an intense workout that will push your body to its absolute limits, search no further. Generally speaking, this is a CoachUp cultivated tip guide to a workout that will test your skills, endurance, and desires. In fact, some of swimming's most advanced athletes love going under this microscope. Typically, you'll be able to see instant feedback during a workout like this, because it'll be painfully obvious where you lack -- so get out there and start learning!