- Aerobic exercise provides a ton of benefits, from a lift in mood to more toned muscles.
- Some of the benefits can emerge within minutes, while others might take several days or weeks to crop up.
- A new study suggests that aerobic exercise also changes the makeup of the microbes in our gut.
Aerobic exercise, or cardio, might be the closest thing we have to a miracle drug.
When we commit to regular workouts that raise our heart rate and get us moving and sweating for a sustained period, magical things happen to our mind and body. We start to think more clearly, feel better about ourselves, and even build buffers against age-related cognitive decline. Our lungs and heart get stronger, too.
But cardio may have other less obvious benefits. A small study published in November suggests that activities like walking, swimming, and running – while they are no shortcut to weight loss – also change the makeup of the microbes in our gut that play a role in things like our energy levels and inflammation, an early warning sign of illness.
“These are the first studies to show that exercise can have an effect on your gut independent of diet or other factors,” Jeffrey Woods, a professor of kinesiology and community health at the University of Illinois who led the research, said in a statement.
That could have important implications for learning more about why exercise seems to be so uniquely capable of lifting our spirits and energizing our bodies.
Cardio affects our gut – but not in the way you might think
For the most recent study, published in the journal Medicine & Science in Sports Exercise, Woods and a team of other scientists looked at 32 lean and obese women who had been essentially inactive before the study.
For three days a week over six weeks, the participants cycled, walked, ran on a treadmill, or used an elliptical machine. They started with a moderate 30-minute workout and worked up to a vigorous one-hour burst by the end of the study.
“They had a choice of activity on any given day, but most chose the treadmill,” Woods told Business Insider.
After six weeks, the participants were instructed to go back to their normal sedentary lifestyles for another month and a half.
The researchers looked at the microbes in participants’ guts using fecal samples immediately after their exercise program, then again after six weeks of not working out. They found that after weeks of exercise, there was an increase in participants’ concentrations of butyrate, a type of fatty acid that helps keep our guts happy by tamping down on inflammation and producing energy. They soared in the lean participants and picked up modestly among those in the obese group.
“The bottom line is that there are clear differences in how the microbiome of somebody who is obese versus somebody who is lean responds to exercise,” Woods said. “We have more work to do to determine why that is.”
How aerobic workouts clear our minds and lift our mood
- Al Bello/Getty Images
Precisely how cardio affects different types of bodies remains somewhat murky. But its powerful ability to clear the mind has been well documented by a handful of recent studies.
Aerobic exercise “has a unique capacity to exhilarate and relax, to provide stimulation and calm, to counter depression and dissipate stress,” according to an article in the Harvard Medical School blog “Mind and Mood.”
Some benefits of cardio, like a lift in mood, can emerge as soon as a few minutes into a sweaty bike ride. Others, like improved memory, might take several weeks to crop up.
The reason aerobic workouts seem to lift our spirits seems related to its ability to reduce levels of natural stress hormones, such as adrenaline and cortisol, a recent study in the Journal of Physical Therapy Science found. Activities like running and swimming also increase overall blood flow and provide our minds fresh energy and oxygen – another factor that could help us feel better.
Those benefits may be one of the reasons that working out is so helpful for people with depression. A pilot study with people with severe depression found that 30 minutes of treadmill walking for 10 consecutive days was “sufficient to produce a clinically relevant and statistically significant reduction in depression.”
But the mental benefits of heart-pumping workouts aren’t confined to better moods. This kind of exercise also seems to improve our memory and may even guard against some of the detrimental effects of aging.
A study published in May found that for adults aged 60-88, walking for 30 minutes four days a week for 12 weeks appeared to strengthen connectivity in a region of the brain where weakened connections have been linked with memory loss. And a recent study in older women who displayed potential symptoms of dementia found that aerobic exercise was linked with an increase in the size of the hippocampus, a brain area involved in learning and memory.
A study in the British Medical Journal suggests that if you’re over 50, the best results come from combining aerobic and resistance exercise, which could include anything from high-intensity interval training, like the seven-minute workout, to dynamic-flow yoga, which intersperses strength-building poses like planks and push-ups with heart-pumping dance-like moves.
So what are you waiting for? Get moving, and keep it up.