Group 3: the subjects were instructed to do lower intensity exercise on their own.
Group 4: the control subjects were not instructed to do any exercise.The results showed greater adherence in the unsupervised home-based programmes,
than in the supervised programme. However, all subjects who had been instructed to do
some exercise showed an increase in cardiovascular fitness compared with the control
group. The authors suggested that the results from this study provide insights into
the development of successful national campaigns to promote exercise behaviour that
involve a minimal and cheap intervention and argued for an emphasis on unsupervised
individual exercising.
Other factors that appear to play a role in developing successful exercise programmes
are the use of behavioural contracts, whereby the individual signs a contract with an
instructor agreeing to participate in a programme for a set period of time (e.g. Oldridge
and Jones 1983) and the use of instructor praise and feedback and flexible goal-setting
by the subject (e.g. Martin et al. 1984). These factors involve supervised exercise
and suggest that individualized exercise programmes may not be the only form of
intervention.
The social/political climate therefore has implications for predicting and promoting
exercise. However, even if councils provide the facilities and government programmes
are established, individuals have to make decisions about whether or not to par-
ticipate. Research has, therefore, also examined the individual predictors of exercise
behaviour.Individual predictors of exercise
Dishman and colleagues (Dishman 1982; Dishman and Gettman 1980) carried out a
series of studies to examine the best individual predictors of exercise and suggested that
these factors can be defined as either non-modifiable or modifiable.Non-modifiable predictors of exercise
Dishman (1982) reported that non-modifiable factors such as age, education, smoking,
ease of access to facilities, body fat/weight and self-motivation were good predictors of
exercise. The results of a prospective study indicated that the best predictors of exercise
behaviour were low body fat, low weight and high self-motivation (Dishman and
Gettman 1980). However, whether factors such as access to facilities and self-motivation
should be regarded as non-modifiable is problematic. King et al. (1992) reported the
results of a study that evaluated the factors predicting being active in leisure time. They
described the profile of an active individual as younger, better educated, more affluent
and more likely to be male. However, it is possible that other individuals (less affluent/less
educated) may be more active at work. Research has also examined ethnic differences in
predicting exercise behaviour. Several studies indicate that blacks are less active than
whites, that black women are especially less active and that these differences persist even
when income and education are controlled (e.g. Shea et al. 1992).176 HEALTH PSYCHOLOGY