Staying aerobically fit, especially through middle age and beyond, can delay biological aging by up to 12 years, a study has found.
That work will also help prolong independence during old age, according to a Canadian study published in the British Journal of Sports Medicine.
Aerobic exercise -- such as jogging, swimming, cycling or walking -- improves oxygen consumption and boosts metabolism.
Declining aerobic power is a fact of life once people hit middle age. People see their aerobic capacity decline by about five millilitres per kilogram-minute every decade.
Once it falls below 18 ml/kg-min in men and 15 ml/kg-min in women, it becomes very difficult to do almost anything without experiencing severe fatigue.
A typical, 60-year-old sedentary man will have an aerobic capacity of about 25 ml/kg-min. His aerobic capacity would have been double that at age 20.
But research has found that high-intensity aerobic exercise over a relatively long period can boost a person's aerobic power by 25 per cent.
For the 60-year-old sedentary man, that would be equivalent to a gain of about 6 ml/kg-min. That can be likened to gaining back 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 study author Dr. Roy Shephard, at the University of Toronto's faculty of physical education and health and department of public health sciences.
There are other benefits:
- reduced risk of serious disease;
- faster recovery after injury or illness; and
- reduced risk of falls because of muscle power, balance and co-ordination.
While the current study touted high-intensity training to boost aerobic capacity, an August 2007 study found that middle-aged people could obtain other health benefits even from moderate exercise.
Such exercise can reduce triglyceride levels in the blood. High triglyceride levels are linked to artery disease and pancreatitis.
Moderate exercise could also boost the amount of HDL or "good" cholesterol in the blood.
Other studies have recommended weight-training for older people to boost muscle strength, and even recommended supplements like creatine and CLA to help that process -- although they should consult their physicians first.
The benefits of strength training can even extend to people in their 80s and those with heart problems.
In April 2007, a British study also found that the 50-plus set benefited from a supportive environment of their peers when exercising -- and that without one, they'd rather work out alone than with bunch of Spandex-clad 20-somethings.
