You’ll activate your entire core during lifts.
Instead of engaging these muscles by simply giving yourself the cue, it’s more effective to do so by hissing when you exhale, says Matt Berenc, CSCS, Beverly Hills-based director of the Equinox Fitness Training Institute.
Use Berenc’s guidelines: Hold your breath when you initiate a lift to create pressure and stability in your core. Then, halfway through the lift, part your lips, keeping teeth together, and slowly exhale so that your breath makes a hissing sound. This allows you to keep the abs tense. When you reach the top of the movement, inhale.
“When most people engage their core consciously, they focus on squeezing their abs,” Berenc explains, “but your core is a cylinder made of a lot of different muscles.” Hissing when you exhale activates the entire cylinder, keeping you stable and making every lift safer and stronger.