High-intensity aerobic exercise can reduce risk of cancer

By Alice Clifford via SWNS

High intensity aerobic exercise can slash the risk of cancer spreading by 72 percent, a new study claims.

Metastatic cancer is also known as Stage Four and refers to cancer that has spread throughout the body.

During exercise muscles burn glucose, a sugar that is a vital energy source for all living things.

Yet during high intensity aerobic exercise such as sprinting or a HIIT class, internal organs compete with the muscles to consume glucose.

As a result, there is much less energy available for tumors, meaning the cancer cannot spread and the tumor can even shrink in size.

What is more, if a person exercises regularly the tissues of internal organs can adapt and become similar to muscle tissue, making them more efficient at consuming energy.

"Our study is the first to investigate the impact of exercise on the internal organs in which metastases usually develop, like the lungs, liver, and lymph nodes," said Professor Carmit Levy from the Department of Human Genetics and Biochemistry at Tel Aviv University and co-author of the study.

“Examining the cells of these organs we found a rise in the number of glucose receptors during high-intensity aerobic activity - increasing glucose intake and turning the organs into effective energy-consumption machines, very much like the muscles.

“We assume that this happens because the organs must compete for sugar resources with the muscles, known to burn large quantities of glucose during physical exercise.

"Consequently, if cancer develops, the fierce competition over glucose reduces the availability of energy that is critical to metastasis.

“Moreover, when a person exercises regularly, this condition becomes permanent: the tissues of internal organs change and become similar to muscle tissue. We all know that sports and physical exercise are good for our health.

“Our study, examining the internal organs, discovered that exercise changes the whole body, so that the cancer cannot spread, and the primary tumor also shrinks in size."

While people can survive metastatic cancer, the likelihood is low and the treatment is aggressive.

According to the charity Cancer Research, around five percent of people will survive stage four lung cancer for five years or more after their diagnosis.

Metastatic cancer is also the leading cause of death in Israel where this study took place.

The team from Tel Aviv University combined data from mice that were put under a strict exercise regime with data from healthy human volunteers. They examined both before and after running.

Researchers monitored 3,000 people for around 20 years. Over this time they found that those who took part in regular high-intensity aerobic activity were 72 percent less likely to develop metastatic cancer than those who didn’t do any physical exercise.

The mice showed similar results. The study looked at the internal organs of physically fit animals before and after exercise.

After injecting the mice with cancer, they found that aerobic activity significantly reduced the development of metastatic tumors in the lymph nodes, lungs and liver.

The study, published in the journal Cancer Research, found that in both humans and mice these results were due to the minimal glucose available for tumors as the organs and muscles competed for sugar resources.

"Studies have demonstrated that physical exercise reduces the risk for some types of cancer by up to 35 percent," Levy said.

“This positive effect is similar to the impact of exercise on other conditions, such as heart disease and diabetes.

“In this study we added new insight, showing that high-intensity aerobic exercise, which derives its energy from sugar, can reduce the risk of metastatic cancer by as much as 72 percent.

“If so far the general message to the public has been 'be active, be healthy', now we can explain how aerobic activity can maximize the prevention of the most aggressive and metastatic types of cancer."

Dr. Yftach Gepner from the School of Public Health and the Sylvan Adams Sports Institute at Tel Aviv University, and co-author of the study, added: "Our results indicate that unlike fat-burning exercise, which is relatively moderate, it is a high-intensity aerobic activity that helps in cancer prevention.

“If the optimal intensity range for burning fat is 65-70 percent of the maximum pulse rate, sugar burning requires 80-85 percent - even if only for brief intervals. For example: a one-minute sprint followed by walking, then another sprint.

“In the past, such intervals were mostly typical of athletes' training regimens, but today we also see them in other exercise routines, such as heart and lung rehabilitation.

“Our results suggest that healthy individuals should also include high-intensity components in their fitness programs.

"We believe that future studies will enable personalized medicine for preventing specific cancers, with physicians reviewing family histories to recommend the right kind of physical activity.

“It must be emphasized that physical exercise, with its unique metabolic and physiological effects, exhibits a higher level of cancer prevention than any medication or medical intervention to date."