Brett Williams, NASM
Brett Williams, a fitness editor at Men's Health, is a NASM-CPT certified trainer and former pro football player and tech reporter who splits his workout time between strength and conditioning training, martial arts, and running. You can find his work elsewhere at Mashable, Thrillist, and other outlets.

Spice Up Your Cross Training With This 30-Minute HIIT Workout
Make your home workout more efficient.