Exercise is one of the weapons against cancer. And not only as a sports therapy for cancer patients, but also as a proven preventive measure, so that malignant tumors do not develop in the first place. At FOCUS Online, medical professor Martin Halle explains which sport and how much of it has the best effect.

Anyone who is active in sports stays healthier in the long run, especially with regard to cardiovascular diseases and diabetes. Cancer patients who are physically active as much as possible also strengthen their psyche and are often better able to cope with illness and chemotherapy than those who are inactive. But could sport also be an effective measure to prevent cancer – like eating right and not smoking? More and more studies show that sport can also protect against cancer.

Martin Halle, senior medical director of the chair and polyclinic for preventive and rehabilitative sports medicine at the medical faculty of the Technical University of Munich, is researching this topic. FOCUS Online spoke to him about the influence of exercise on cancer risk.

FOCUS Online: How much does sport protect against cancer and does it basically affect every form of cancer?

Martin Halle: The studies show that the preventive effect of sport is around 25 percent. The risk of cancer falls accordingly on average by a quarter. Regular physical training has a particularly strong preventive effect on certain forms of cancer – these are the three most common

When it comes to the risk factors for colon cancer, everyone immediately thinks about nutrition – too much meat, sausage, hardly any fiber. How risky is lack of exercise?

Halle: Diet certainly has a major impact on colorectal cancer. But much more important in prevention is physical training and, of course, not smoking.

And what about breast cancer and prostate cancer?

Halle: The biggest risk factors for breast cancer are obesity and lack of exercise, as well as metabolism with insulin resistance and diabetes. In connection with prostate cancer, too little exercise has also been proven to be a risk factor, but it has not yet been studied quite as well as with the two most common types of cancer – colon and breast cancer.

A PDF from FOCUS online – Around half a million people are diagnosed with cancer in Germany every year. However, many factors can protect against tumor disease: check-ups, diet, exercise and much more. In this e-paper we summarize the most important knowledge about cancer and how to reduce the risk of developing the disease.

But those who do a lot of sport usually live healthier overall?

Halle: A factor that certainly plays a role and must not be overlooked. If the risk factors are considered in a differentiated manner and the cancer figures are analyzed statistically, however, the great preventive effect of sport is clearly established.

The two most common non-communicable diseases – i.e. cancer, but also cardiovascular diseases – overlap here. Regular exercise protects against cancer, but also against vascular diseases such as high blood pressure and its consequences.

Why can physical activity protect against cancer, what happens in the cells?

Halle: These mechanisms are becoming more and more understood. A particularly good example is colon cancer: Today, we understand muscles and bones as organs that emit numerous messenger substances during physical activity. Underneath, myokines originate from muscle and osteokines from bone. The myokines in turn reach many other organ systems via the blood, including the intestinal mucosa. Here the special messenger substances demonstrably prevent the formation of polyps. Myokin SPARC, the abbreviation for Secreted protein acidic and rich in cysteine, plays an important role in this.

Martin Halle is the senior medical director of the chair and polyclinic for preventive and rehabilitative sports medicine at the medical faculty of the Technical University of Munich. He is a specialist in internal medicine, cardiology and sports medicine and heads a large outpatient clinic for preventive cardiology and sports medicine at the University Hospital Rechts der Isar. His specialty is the prevention, therapy and rehabilitation of internal diseases, especially cardiovascular diseases.

Do myokines also protect against breast cancer?

Halle: There are also these mechanisms in breast cancer that are set in motion by sport. However, the messenger substance responsible has not yet been identified. The pathway presumably runs via metabolism and insulin resistance, the inflammatory response and the immune system, and fatty acids. For protection against breast cancer, this means: Prevention consists of three elements

How much time should we invest so that we can prevent cancer with sport?

Halle: Cancer prevention is successful when the muscles are addressed. This can be achieved with endurance and strength training. In order to stimulate the bones, I need strength and impact training – like jogging by putting my feet on them.

As a rule of thumb: If I activate my muscles and bones for 20 minutes a day with a combination of strength and endurance training, I’m on the safe side in terms of prevention. However, a certain intensity must also be achieved. So jogging is better than walking. Only then does the myokin release start.

The 10-week program – Martin Halle

So rather be short and sweet and work up a sweat like in your 7-minute workout than go for a brisk walk for hours?

Halle: Yes, the exercises are very intensive and if you do them every day, you have achieved a lot. You should see this as an account that you are paying into: Do ​​these seven exercises every day: with jumping jacks, crunch, plank, leg extension, etc. This is doable and anyone can actually invest this total of probably ten minutes. And if I don’t make it one day, I should do it the next day so that the daily 10-minute account is correct again.

How important are popular endurance sports like swimming or cycling as a preventive measure against cancer?

Halle: Swimming is not that effective in terms of cancer prevention. Cycling does, however, because it activates the muscles. However, because the impact effect is low when cycling, hardly any osteokines are formed. Nevertheless, it is good for obese people, for example, because it only puts little strain on the knees.

Both types of sport naturally also have other beneficial effects on health – vascular tone, cardiovascular system, and metabolism. With regard to cancer prevention, however, the following applies: short but intensive units particularly stimulate the formation of the messenger substances in muscles and bones that protect against cancer.

Longer units, such as a weekly workout or a mountain tour, don’t have to be there?

Hall: On the contrary. In addition, they are a good thing because they strongly stimulate the myokines and immune system. They act like boosters against cancer and are very important!

If I start training today – jogging, weight training, intensive exercises – when will the cancer protection kick in?

Halle: It’s just not like losing weight, another important preventive measure – where results only show up after weeks and the protective effect only starts then. The good news: the effect starts with the first workout, as soon as the muscles and bones are stressed. Both immediately form the protective messenger substances.

And what effects can too much exercise have in terms of cancer risk? Is it well known from competitive athletes that they can be more at risk of infection due to intensive training?

Halle: According to the studies, this plays no role in relation to tumor diseases. On the contrary: When it comes to cancer prevention, more training is better than less.