When I became ill, I didn’t have the energy even to think about exercising. It was as if all the strength had been drained from my body. At first, all my energy seemed to be sapped into worrying about the future.

I did remember however, that exercise had helped me on previous occasions when life was difficult, and my mood was low. I had often known grief and sorrow to be dispersed by a good training session. I tried to motivate myself to get going again, but the prospect of better mood was not in itself a sufficient stimulus to tempt me back to the jogging track.

The necessary extra motivation to put my jogging shoes on again came when I discovered recent Danish studies showing what a powerful effect exercise can have in strengthening immune defense and enabling it to combat cancer cells.

This research shows how high-intensity training can be particularly beneficial in the battle against cancer. Among other effects, the adrenaline that is secreted into the bloodstream during intense exercise hinders tumors from spreading. As part of the preparation for ‘fight or flight,’ the high adrenaline levels mobilize the immune system’s natural killer cells (NK cells) to find and eliminate the cancer cells.1

Another study demonstrated a further enhancement of the effects of exercise. Muscle contraction generated a messenger substance that facilitated the entry of immune cells into cancer tumors.

Physical activity can help to attack cancer from several directions. Exercise stimulates immune defense, maintains a healthy hormone balance, helps to regulate the blood sugar, and also has an anti-inflammatory effect. Regular exercise improves physical health generally and reduces stress.

Several recent studies show that the incidence of cancer is less among people who are physically active and also that among people who do have cancer, the relapse rate is less in those who are physically active.2

Physical training has a direct stimulant effect on the immune system. It is also one of the important influences in maintaining a normal, healthy hormone balance. Physical activity reduces excess levels of estrogen and testosterone, which can stimulate growth of certain cancers (especially in breast, ovary, prostate, uterus, and testicle). Exercise also helps to reduce the levels of blood sugar and, therefore, of insulin and the growth-promoting factor IGF-1. It also reduces the amount of fatty tissue that can absorb and store carcinogenic toxins, and it damps down inflammation, alleviates stress, and improves physical health in general.

I try to put in 4 or five training sessions a week, but just one or two intensive sessions.

Even though high- intensity training might be the most effective, remember that your body also needs rest and time to recover. Every type of activity has its benefits for body and mind.

Remember, every session matters!

1 L. Pedersen, M. Idorn, G.H. Olofsson, B. Lauenborg, I. Nookaew, R.H. Hansen, H.H. Johannesen, J.C. Becker, K.S. Pedersen, C. Dethlefsen, J. Nielsen, J. Gehl, B.K. Pedersen, P. Straten, P. Hojman: ‘Voluntary Running Suppresses Tumor Growth through epinephrine- and IL-6-Dependent NK Cell Mobilization and Redistribution,’ in Breast Cancer Res Treat., (6) 2017: 399-408.

2 L. Pedersen, M. Idorn, G.H. Olofsson, B. Lauenborg, I. Nookaew, R.H. Hansen, H.H. Johannesen, J.C. Becker, K.S. Pedersen, C. Dethlefsen, J. Nielsen, J. Gehl, B.K. Pedersen, P. Straten, P. Hojman: ‘Voluntary Running Suppresses Tumor Growth through epinephrine- and IL-6-Dependent NK Cell Mobilization and Redistribution,’ in Breast Cancer Res Treat., (6) 2017: 399-408.