Exercise and Health

4 June 2008

Walking is as effective as more vigorous exercise, for example running, in reducing the risk of heart attack and strokes for women. A study of 73,743 post-menopausal women from 50 to 79 years of age in the Women's Health Initiative Observational Study, found that brisk walking for about two and a half hours a week reduced the risk of heart disease and stroke by about one-third, whilst prolonged sitting increased the risk. (N Engl J Med 2002; 347:716-725).

It is known that physical activity is associated with a lower risk of coronary heart disease (CHD) and also that markers of inflammation (high levels of C-reactive protein, white blood cells and fibrinogen) are associated with a higher risk of CHD. To examine a possible relationship, 3.638 healthy men and women over 40 years of age were tested for inflammatory signs and questioned on their physical activity. Higher physical activity was associated with up to 40% lower inflammatory markers. (Arch. Int. Med. 2002;162(11):1286-92).

A recent study suggests that exercise might be able to offset some of the mental decline associated with the ageing process, possibly by improving the flow of oxygen-rich blood to specific regions of the brain. The team of Duke University Medical Center researchers, who demonstrated in late 1999 that aerobic exercise is just as effective as medication in treating major depression in the middle-aged and elderly (see NEWS 64), has now reported that the same exercise programme also appears to improve the cognitive abilities of these patients.

The exercise involved 30 minutes riding a stationary bicycle, walking or jogging three times a week. Among the exercisers, the researchers found significant improvements in the higher mental processes of memory and the so-called executive functions, which include planning, organisation and the ability to mentally juggle different intellectual tasks at the same time. These improvements were above and beyond what would be expected after the depression had lifted, the researchers said. Exercise specifically had its beneficial effect in areas of cognitive function that are rooted in the frontal and pre-frontal regions of the brain. Other cognitive functions such as attention, concentration and psychomotor skills did not appear to be affected by the exercise program [Journal of Aging and Physical Activity, 9 (1)].

Researchers at the University of Georgia, USA, have investigated the mechanism of exercise on anxiety and stress levels. Fourteen (anxiety-prone) undergraduate psychology students were put on stationary bikes under four conditions involving different combinations of just sitting, studying while just sitting, studying while pedaling, and just pedaling. Anxiety only fell in those who exercised without any studying involved. The exercise was kept mild enough to avoid stimulating endorphins which are also known to lower anxiety.

Qigong wisdom teaches that even if people are too ill to practise, they can benefit from imagining themselves doing the practice. Researchers from the Cleveland Clinic Foundation had previously found that visualising exercise was effective in increasing strength in the little finger. Turning to bigger muscles, they recently asked 10 volunteers aged 20 to 35 to imagine flexing one of their biceps as hard as possible for five sessions a week. After a few weeks, tests on their biceps showed a 13.5% gain in strength, a benefit that was maintained for three months after the end of the visualisation period (New Scientist, vol 172 issue 2318, 24/11/2001, page 17).

Categories: Lifestyle