Should I Wear a Weight-Lifting Belt?
Most people think that weight belts support the back and can help prevent injury. That's generally true, but a better understanding of the mechanics will change how many people use their equipment. Even some weight belt manufacturers don't understand how a belt is supposed to work, which is revealed when they make the back of the belt wider than the front.
Also to add to this I would say that a weight lifting belt is also NOT a waist trainer and I promise you it’s not going to make your waist any smaller. So you can stop wearing it as
To talk about belts, we first have to talk about breathing. Most people are taught to inhale on the eccentric (negative) part of an exercise and to exhale during the concentric (positive). While you should definitely breathe, this isn't the method that works best when you need to produce a large amount of force. In the everyday world when you need to move something heavy—a couch or an Atlas stone—you take a big breath, push or pull while holding your breath, and only exhale after completing the movement.
We use this technique—known as the Valsalva Maneuver—when we're performing certain exercises at near-maximal effort. Holding your breath against a closed glottis while increasing you thoracic abdominal pressure braces you, and allows you to lift more weight. You'd never see a powerlifter squatting 250kg while slowly breathing out.
When you inhale, pressure increases in your thoracic cavity; this pressure is further increased when you flex your abs. In this regard, the muscles of your abdomen serve chiefly to apply pressure to the anterior side of your spine, attempting to balance the forces produced by the extensors on the backside. In other words, this pressure keeps you from being crushed by the weight when you squat.
The back muscles apply force, position and support to the spine from the back while the abdominal wall and increased abdominal pressure from a deep breath support it from the front. A weight belt's main function is to add support from the front by increasing abdominal pressure.
There is no need to wear a belt all the time. There is a lot of discussion in the fitness community about whether you should wear a belt at all. Some people believe you should only rely on your own abilities to stabilize heavy loads. I don't intend to delve into that debate here, but I will say two things: first, under a heavy load, a belt can help reduce your odds of getting an orthopedic injury. Second, a belt will definitely aid in lifting performance.
In my opinion, a weight belt is only necessary during near the max attempts on compound lifts, definitely not when you're on a bicycle. You shouldn't wear a belt with loads that you can easily support—below 90% of your one rep max on big, barbell lifts.