Those mid-class sprint intervals are tough. But experts break down whether they really get you ready for race day.

High-intensity interval training (a.k.a., HIIT) is a triple threat: “It’s quick, easy, and effective,” says Angela Gargano, a certified trainer and creator of Strong Feels Good & Pull-up Revolution.

Anyone can do it—and it's fun. The Taylor Swift Treadmill Strut (TSTS) is a fun, high-energy treadmill workout routine created by Allie Bennett, who develops treadmill-based workout routines (which ...