example, Dr William Bird (2001, cited in Murphy, 2001) has established ‘The Green
Gym’—a conservation project that combines the idea of ecological work with purposeful
physical activity. Specifically, this project requires people to “work out” by undertaking
tasks such as building stiles, cutting trees and repairing fences in natural surroundings. As
yet, however, the health and fitness impacts of this programme have not been evaluated
adequately. More recently, however, Bodin and Hartig (2003) investigated the relative
effects of different environmental contexts on the benefits yielded by a bout of vigorous
exercise. In particular, they conducted a field experiment in which twelve regular runners
exercised alternately in park and urban environments. These environments differed with
regard to such factors as the extent of greenery encountered, proximity to water and
amount of motor traffic apparent. The hypothesis was that the psychological benefits of
running would be stronger for the runners in the park than in the urban condition. Results
showed that although the runners preferred the park to the urban environment, and
perceived it as being more psychologically “restorative”, no significant effect of exercise
environment was evident on psychometric indices of emotional and attentional variables.
Having raised some questions about the symbolic meaning of exercise in modern life,
let us consider what the term “physical fitness” means. According to Buckworth and
Dishman (2002), this concept of fitness refers to people’s “capacity to meet successfully
the present and potential physical challenges of life” (p. 29). In a similar vein, the
President’s Council on Physical Fitness (Fitness Fundamentals, 2003) defined it as “the
ability to perform daily tasks vigorously and alertly, with energy left over for enjoying
leisure-time activities and meeting emergency demands. It is the ability to endure, to bear
up, to withstand stress...and it is a major basis for good health and well-being” (p. 1).
According to this council, there are four main components of fitness. First, “cardio-
respiratory endurance” (or aerobic fitness) refers to the ability of the circulatory and
respiratory systems to supply oxygen and nutrients to body tissues during sustained
physical activity. In other words, it is an index of the efficiency with which one’s heart,
lungs and caridiovascular system work. It is assessed in the laboratory using the “VO 2
max” test (which measures the body’s maximal oxygen uptake or its aerobic capacity for
endurance exercise) and in field settings by tests like the “one mile run” or the “one mile
walk”. The second component of fitness is “muscular strength” or the ability of the
muscles to exert force for brief periods of time. It is assessed commonly by the
“handgrip” test. Third, “muscular endurance” refers to the ability of the muscles to
sustain repeated contractions and to exert force against a fixed object, without fatigue. It
is usually measured using isokinetic machines. Finally, fitness is also indicated by
muscular “flexibility”, understood as the range of motion available to a joint without
discomfort or pain. It may be measured in the lab using apparatus like the “goniometer”
and in field contexts using various “sit-and-reach” exercises. Another putative index of
fitness is “body composition” as assessed by the ratio of fat to lean body mass (LeUnes
and Nation, 2002). In summary, the health-related components of physical fitness include
cardiovascular fitness, muscular strength, endurance and flexibility, and body
composition.
Given the importance of regular physical activity for a healthy lifestyle, how does
health psychology fit into the picture? According to Buckworth and Dishman (2002), this
latter discipline is concerned with “the scientific understanding of how behavioural
principles relate to health and illness” (p. 10). It differs from exercise psychology in at
Sport and exercise psychology: A critical introduction 218