A recent study published in the journal Mechanisms of Aging and Development confirms the "anti-aging" effect of high-intensity training.
Telomere shortening occurs as you age, however the factors involved are not entirely understood as of yet. The study was conducted to determine whether age-associated telomere shortening is related to habitual endurance exercise and maximal aerobic capacity.
The results suggest there's a direct association between reduced telomere shortening in your later years and high-intensity-type exercises.
The authors' state:
"The results of the present study provide evidence that leukocyte telomere length (LTL) is related to regular vigorous aerobic exercise and maximal aerobic exercise capacity with aging in healthy humans.
LTL is not influenced by aerobic exercise status among young subjects, presumably because TL is intact (i.e., already normal) in sedentary healthy young adults.
However, as LTL shortens with aging it appears that maintenance of aerobic fitness, produced by chronic strenuous exercise and reflected by higher VO2max, acts to preserve LTL.
… Our results indicate that leukocyte telomere length (LTL) is preserved in healthy older adults who perform vigorous aerobic exercise and is positively related to maximal aerobic exercise capacity. This may represent a novel molecular mechanism underlying the "anti-aging" effects of maintaining high aerobic fitness."
But that's not all.
High-intensity interval-type training also boosts human growth hormone (HGH) production. A 2003 study published in the journal Sports Medicine found that "exercise intensity above lactate threshold and for a minimum of 10 minutes appears to elicit the greatest stimulus to the secretion of HGH."