Doctors frequently recommend lifestyle changes—in particular, increased
exercise—to patients who complain of intestinal gas. But because there were no
scientific experiments to back up the recommendation, no one knew for sure that
physical activity was in fact effective.

Putting it to the test

Now a team of researchers in Spain offers evidence that exercise can help
move gas out of the body. The study was small, involving only eight people. For
two hours, they were given a mixture of nitrogen, carbon dioxide, and oxygen
gases, bubbled into water. The mix was introduced into the jejunum, the middle
section of the small intestine. In order to collect and measure the release of
gas, a catheter (slender tube) was placed in the rectum.

The research team took various measurements every 15 minutes, including how
much gas was passed. They also noted the participants’ abdominal girth and their
perceptions of bloating, cramping, and other abdominal sensations. All these
observations were made while the people were at rest or pedaling on a modified
exercise bicycle.

The results

When the measurements were compared, the researchers found that during rest
the participants released 10% less gas than was pumped into them. That means
they had retained gas. But during periods of physical activity, more gas was
released than had been pumped in—indicating that the participants were releasing
not only all the gas that had been put into them but also some produced
naturally by the body. The physical activity reduced abdominal swelling.

Although these findings showed that exercise helped eliminate gas in healthy
people, it’s not known what effect it might have in people with irritable bowel
syndrome or bloating. The researchers say they’re unsure just how exercise
relieves excess gas, but one theory is that it increases pressure in the
abdomen.