Intense aerobic exercise can reduce the risk of metastatic cancer, Israeli scientists have found. A study by scientists from Tel Aviv University was published in the journal Cancer Research. In an epidemiological study of cancer, scientists followed three thousand people for almost 20 years. The risk of developing metastatic cancer was 72% lower in those people who reported regular high-intensity aerobic exercise. The experiment conducted on mice allowed the researchers to identify a major mechanism for reducing the risk of metastatic cancer. When scientists artificially induced cancer in mice, it rarely progressed to metastatic form. This was because exercise increased the animals' intake of glucose from their internal organs. Sugar is also essential for tumors because of their intense metabolism, and its uptake by the organs decreased the energy availability to the tumor cells. With regular exercise, this condition became permanent and was accompanied by changes in the tissues of internal organs. The scientists added that while the optimal heart rate for fat burning is 65-70% of the maximum heart rate (depending on age), it takes 80-85% for the internal organs to absorb glucose. Short intervals are sufficient: for example, one minute of fast running, then switching to walking and another minute of fast running. This approach is known as "high-intensity interval training. In fact, exercise is more effective in preventing cancer than any medication or medical intervention.