Of course you can’t fill your belly with air, but you can consider the concept when it comes to supporting your lower back during lifts. More than likely you would be holding your breath if you were trying to lift something heavy. Almost all individuals, from Olympic weight lifters to weekend warriors, will hold their breath while straining.
Warm-up reps, heavy singles…just about any time you move weight you should be focused on mid-line stability and lower back integrity. In order to maintain the structural integrity of your spine while lifting heavy, positive pressure in the thoracic cavity must be established and maintained during the core of the lift.
Take a deep breath and hold it. This is known as the Valsalva Maneuver: the proper term for holding the breath against a closed glottis (throat/larynx) while pressure is applied by the abdominal and thoracic muscles.
We call this technique of creating pressure in the abdomen “Bracing.”
To develop this pressure during a heavy lifting exercise, fill your lungs to capacity by breathing as deeply as possible into your lower belly and then holding your breathe for the duration of the lift.
With positive pressure in the lungs, the diaphragm presses downward, thereby tightening the abdominals and securing the structural integrity of the spine—the back muscles position and support the spine from the back; the abs and obliques, with the aid of a big breath, support it from the front.
Bracing, or filling your trunk with pressure, is the best way to engage the core and create stability throughout the midsection.
Its important to note—tightening the abdominals does not refer to sucking (vacuuming) in your stomach. Rather, think about pressing your abdominals down and out. Consider the concept of tightening your stomach as you’re about to get punched in the gut.
Get in the habit of breathing correctly during your lighter sets, this way, when the load gets heavy the correct breathing pattern will be instinctual.