Exercising with friends allows you to morally support each other, and, when the time comes, to have the collective muscle to beat up an asteroid headed for Earth. Get strength in numbers with this Groupon.

Choose Between Two Options

• $54 for one month of unlimited CrossFit classes (a $120 value)
$89 for two months of unlimited CrossFit classes (a $205 value)

Seasoned trainers lead students of all fitness levels through high-intensity workouts. The constantly varied routines are made up of functional exercises such as gymnastics, running, and weightlifting. See the schedule.

Phalanx CrossFit

Phalanx CrossFit is christened after the ancient Greek word meaning "a group of individuals working closely together to achieve a common purpose." Here, enthusiastic trainers encourage students to help keep one another motivated in the intimate, no-frills gym to up their fitness and overall quality of life. Surrounded by massive tires, kettlebells, and pull-up bars, Zack Luikart, Tammy Lancaster, and their staff of seasoned fellow trainers guide students of all athletic backgrounds through high-intensity CrossFit workouts. The routines are infused with functional exercises such as weightlifting, running, and jumping, and vary from day to day to prevent workout burnout. In addition to whipping them into shape, the trainers also provide students with tips on nutrition and injury prevention, suggesting therapeutic stretches and the best way to terminate a treadmill you suspect is plotting to tie your shoelaces together.