We spend a lot of our time practicing and evaluating exercise to either relieve or prevent low back pain. We continue to re-learn that simple is often better.

When we talk to former back pain sufferers, one of the most common exercises they do is abdominal bracing (to clarify, we're talking about bracing the abdominal muscles by tensing them, not wearing a brace -- which weakens them). We also often practice bracing because it is the do anytime, anywhere, by anyone exercise. That includes when in a lot of pain or none; whether a ballet dancer or a powerlifter; while driving, sitting at a computer, watching TV, or between sets at the gym.
The Science Behind the Brace
Besides "Bro Science" (from gym rats) and "Pro Science" (from the self-cured), we have evidence from "Hard Science" (from Randomly Controlled Trials or RCTs) supporting bracing.

The most thorough study and the positive results were reported in a TEN YEAR follow up comparing bracing to non-bracing among 600 people with low back pain. (the logistics of such a study alone is staggering) They summarized,
Abdominal bracing added significantly to the effect of strengthening or flexibility exercises.
One of the most important differences among groups was that those practicing bracing in addition to flexibility or strengthening exercises, exercised about twice as often as those practicing flexibility or strengthening without bracing.

Pain frequency (measured as the number of recurrences per year) were also half those of the non-bracers.