Sedentary life 'speeds up ageing'

A recent study of over 1,000 twins found those who were active during their leisure time appeared biologically younger than their sedentary peers. Subjects whose weekly exercise was as low as 16 minutes per week had an average telomere length of 200 nucleotides less than those with the most physical activity per week, around 199 minutes. Telomeres, the repeat sequences of DNA that sit on the ends of chromosomes, are essential for protecting genes from damage. Most active people had telomere length comparable to those of sedentary people who were 10 years younger.

http://news.bbc.co.uk/2/hi/health/7212698.stm