Like "arch hard", you'll often hear the cue "draw in your belly" in hopes of electing proper form when moving heavy weight.
However, this cue rarely achieves the intended goal.
In fact, it often leads to the exact opposite of what we want.
"I understand this cue applies to certain elements of yoga and pilates, but why anyone would use this cue with regards to lifting heavy things I have no idea," says Tony Gentilcore, a Boston-based strength coach and owner of TonyGentilcore.com. "Drawing in actually decreases stability and increases the likelihood of spinal buckling under load."
Instead, it's important to tighten all of your core muscles to improve spinal stability.
Proper bracing of your core doesn't entail sucking in your belly, but rather tightening all of your core muscles. If anything, your belly may come slightly outward during a proper brace.
As we have already beaten to death many times, core muscles are designed to prevent movement of the lumbar spine, so it's best to take advantage of those muscles to make your lifts safer.
Not only will it help save your lower back, but it will also give you a more stable platform during your lifts, which should help you move more weight.
One better cue is to inform the lifter to brace their abs as if they were about to get punched in the stomach, which almost always elicit a good brace of the core musculature.
The Fix: "Brace your core as if you're about to get punched in the stomach."