192 Obesity Treatment
which included stretching, moderate to vigorous aerobics, and calisthenics
three times per week. The results showed that exercise had no effect on
immediate weight loss. By 8 and 18 months, however, only the exercisers
were maintaining any weight loss. Svendsen, Hassager, and Christiansen
(1994) and Van Dale, Saris, and ten Hoor (1990) reported similar results
for women. Although it is possible that the effects of exercise are physio-
logical, research also indicates a role for psychological factors, with exercise
improving self-esteem, confidence, body image, and sense of mastery
(Brownell, 1995).
Exercise and physical health
The aim of obesity treatment is to improve health, and it is generally believed
that weight loss by whatever means is the correct pathway. Exercise is there-
fore recommended as a means to lose weight and bring about improvement
in health status. There is much evidence, however, that physical activity
regardless of weight can create better health for the individual. Physical
activity is related to cholesterol levels, blood pressure, and blood lipids
(Powell et al., 1987), all of which are risk factors for the obese. In addition,
physical activity has also been shown to link directly to mortality. Blair has
carried out much research in this area and has argued that increases in fitness
and physical activity can result in significant reductions in the relative risk
of disease and mortality (Blair et al., 1989, 1995, 1996; Blair, 1993). The
data from one study are shown in figure 9.2.
This study indicated that overweight men and women who showed low
fitness scores had a high risk of all-cause mortality. Those overweight indi-
viduals, however, who showed either medium fitness scores or high fitness
scores showed a substantial reduction in this risk. In sum, physical activity
may not be that effective at promoting weight loss in the short term, but may
be more helpful in promoting any maintenance of weight loss. Regardless
of any changes in weight, exercise may be very effective at improving health.
Exercise and psychological health
Research indicates that exercise also has numerous psychological benefits.
For example, McDonald and Hodgdon (1991) carried out a meta-analysis
of both the correlational and experimental research into the association
between depression and exercise. They concluded that aerobic exercise was
related to a decrease in depression and that this effect was greatest in those
with higher levels of initial depressive symptoms. In an attempt to clarify
the problem of causality, McCann and Holmes (1984) carried out an