Just 15 Minutes of Exercise Can Boost Your Immune System: Here’s How

• A new study finds that short bouts of exercise can help boost your immune system.
• This is linked to the production of “natural killer” cells which are a type of white blood cell.
• The study is small, and experts say more research is needed.

New research has found that just 15 minutes of exercise can improve your immune function.
The findings, which are being presented at the American Physiology Summit in Long Beach, CA this week, discovered that short bursts of physical activity increase the production of natural killer (NK) cells, which are a type of white blood cell that fight infected and cancerous cells in the body.

Just 15 minutes may help with immunity
The small study involved 10 participants between the ages of 18 and 40.
Each participant was instructed to ride a stationary bicycle for 30 minutes at moderate-level intensity.

The researchers drew blood samples from the participants before they started cycling and again at the 15 and 30-minute mark.
They found that levels of NK cells increased after 15 minutes of cycling, but did not continue to increase after 30 minutes of activity.
According to the researchers, this suggests that exercising for around 15 minutes substantially boosts NK cells, which may provide meaningful protection against diseases.

How these white blood cells help keep you healthy
“Natural Killer cells are white blood cells that help destroy infected and diseased cells, such as cancer cells,” explains Fredericson.
NK cells are constantly on the lookout for malignant cells and a lot of NK cells in the body may improve prognosis in various types of cancer. For example, one report found that the number of NK cells in the body was positively associated with survival in people with colorectal cancer.

Exercise boosts the immune system in other ways
According to Tracy Zaslow, MD, a board-certified pediatrician and pediatric and adult primary care sports medicine specialist at Cedars-Sinai Kerlan-Jobe Institute in Los Angeles, the body temperature rises during and right after exercise.
Most bacteria and viruses thrive at a normal body temperature and the heat can make it harder for them to survive, similarly to what happens with a fever.
Physical activity also reduces stress.

“Lower levels of stress hormones may provide some protection against illnesses,” says Zaslow.
This, in turn, can protect emotional well-being and decrease mental health issues like depression and anxiety.
“Stress and depression can lead to chronic inflammation impacting the body’s ability to fight infections,” Zaslow said.

Exercise improves sleep quality and duration, and it’s been shown that a good night’s sleep is a crucial component for optimal immune function, she added.
Finally, exercise can alleviate the harmful effects caused by free radicals and prevent oxidative stress — both of which contribute to chronic health conditions.