High Levels of Physical Activity Prevent Several Aspects of Immunosenescence

We examined 125 male and female cyclists, aged 55 to 79, who had maintained a high level of cycling throughout most of their adult lives. These were not Olympians, but very keen cyclists who were able to cycle 100km in under 6.5 hours for the men, and 60km in under 5.5 hours for the women. At mid-life, people start losing muscle mass and strength at a rate of 1% to 2% per year, making it harder to carry out their normal activities such as climbing stairs. Our bones also become thinner with age and this can eventually lead to diseases such as osteoporosis. We showed that the cyclists did not lose muscle mass or strength as they aged, and their bones only became slightly thinner. We then went on to examine a body system that was not so obviously influenced by physical activity - the immune system. When we compared the immune system of the cyclists to older adults who had not done regular exercise, and to young people in their twenties, we found that their immune systems looked most like the young persons'. In particular, we found that the cyclists still made lots of new immune T cells, produced by an organ called the thymus, which normally starts to shrink after we reach puberty. The older cyclists seemed to have a thymus that was making as many new T cells as the young people's. We investigated why this happened and found that the cyclists had high levels of a hormone called interleukin 7 in their blood, which helps to stop the thymus shrinking. Interleukin 7 is made by...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs