No doubt, practicing a sport makes you look younger. But the effect is also present inside. A new research published in the British Journal of Sports Medicine shows that a person who goes to classes of aerobic fitness may cut down up to 12 years from his/her biological age. Jogging and other types of aerobic
exercise appear to maintain high the body's oxygen consumption and the metabolism.
Aerobic exercise was already connected to decreased risk of severe disease and faster recovery after injury or illness, besides preserving muscle power, balance and coordination, associated with decreased risk of falls.
Aging acts on metabolism: it causes a steady decrease in the maximal aerobic capacity in middle age, by about 5ml/ (kg. min) at each 10 years. When maximal aerobic power decreases under 18 ml in men and 15 ml in women, any physical activity will cause major fatigue.
An average, 60-year-old sedentary man has a maximal aerobic power of around 25 ml, half of the value when he was 20 years aged. The new study shows that on long term, relatively high-intensity aerobic exercise can spur maximal aerobic power by 25% (about 6 ml), translated into 10 to 12 biological years.
"There seems good evidence that the conservation of maximal oxygen intake increases the likelihood that the healthy elderly person will retain functional independence," said co-author Dr Roy Shephard, of the Faculty of Physical Education and Health and Department of Public Health Sciences, at the University of Toronto in Canada.
Oppositely, a research published in January 2008 and carried out by a team at St. Thomas' hospital in London shows that couch potatoes live on average 10 years less than their more active counterparts of the same generation. It seems that sedentary life shortens the lengths of telomeres, the tips of our chromosomes.
Telomeres forms a "chromosomal clock" and they get shorter with each cell division. When their length is too short, the cells lose their capacity of division. This is aging. The average values revealed that the telomeres of those exercising only 16 minutes weekly was shorter with 200 nucleotide base pairs (from DNA's molecule) than the subjects exercising about 3 hours weekly. That means 10 biological years. The same team has found that smoking and obesity have the same effect on telomere length.