Summary of entries in physical fitness and health

The research in this area is complex and wide-ranging and can be grouped as follows: general reviews of the impact of physical activity on various aspects of health; consideration of dose-response relationships; reviews of the relationship between physical activity and cardiovascular health; bone density and osteoporosis; the relationship between sports participation and more general health behaviours among young people; effects of physical activity on the health of older people.

The US Department of Health and Human Services’ seminal, comprehensive, review provides an analysis of evidence of the relationship between physical activity and various aspects of health. It illustrates the positive impacts of activity on a number of systems - cardiovascular, musculosketetal, metabolic, endrocrine and immune. The overall conclusion is that those who are regularly active, even on a moderate basis, have lower mortality rates than the least active. It also outlines the positive impacts of physical activity on various aspects of mental health. Allison’s much shorter review outlines a wide range of physical and health benefits associated with even moderate physical activity and it discusses some of the possible mechanism involved. Cooper et al review evidence about the effect of physical activity on people with various disabilities. Although research indicates that physical activity can contribute to the amelioration of the effects of a range of disabilities, the authors note the need to expand research studies to include people from a range of disability etiologies. They also provide a series of recommendations for the use of physical activity to improve the health and quality of life of people with disabilities.

Farrell and Shields, via a secondary analysis of the English Health Education Monitoring Survey, provide some statistical support for the medical and epidemiological literature. They illustrate that those who claim to participate regularly in sporting activities report significantly higher levels of general health than non-participants, with the average daily duration of participation being positively and significantly related to self-reported health.

Rankinen and Bouchard’s review, based on the contributions of 24 experts from 6 countries, concludes that, despite strong evidence for the beneficial effects of regular physical activity across a range of health factors, the precise nature of the dose-response relationship is unclear and requires more research. Twisk supports this conclusion via a review of physical activity guidelines for children and adolescents. Although acknowledging their public health value, the author suggests that guidelines are based on weak, if suggestive, scientific evidence.

The review by the European Heart Network Expert Group on Physical Activity illustrates that a sedentary lifestyle more than doubles the risk of cardiovascular disease. It summarises the evidence that regular, moderate and accumulated activity can lower heart rate, raise insulin sensitivity, lower blood pressure, raise HDL/total blood cholesterol ratio and helps weight control. Rodriguez et al illustrate that physical activity reduced the risk of ischemic stroke among those with increased left ventricular mass.

Welk and Blair review research on the combined effect of physical fitness and body composition on obesity and health. They conclude that physical activity reduces and/or reverses the development of insulin-resistance, even among overweight or obese individuals

A series of research findings illustrate the positive relationships between physical activity and bone mineral density (BMD) in a variety of sub-populations. In longitudinal studies using various sample sizes, Kemper et al and Puntilla et al illustrate that regular (weight bearing) physical activity is significantly related to BMD at the lumbar spine and femoral neck. In relation to total body and lumbar spine BMD, van Langendonck et al illustrate that the type of sports participation is a significant factor, with high impact sports (ground forces higher than four time body weight) most effective and remaining beneficial for the skeletal health of males aged 40. Ryan et al report on the effects of 6 months whole body resistive training in both young and older men and women. They report that the programme increased muscle mass and improved BMD in the femoral region for all and suggest that if BMD is increased at skeletal maturity reductions might be achieved in facture risk in later years. Supporting this conclusion Neville et al demonstrate the importance of sports involving high peak strain for determining peak bone status, especially in young men and possibly for young women (who are less likely to take part in such sports). Greendale et al, in a study of 42-52 year old women, explore four domains of physical activity (sport, home, work, active living). They illustrate that both sport and weight bearing work in the home were the best, and equal, predictors of greater BMD at lumbar spine and femoral neck sites. The work of Cheng et al raises the one negative note in this literature, finding that high levels of physical activity (running 20 or more miles per week) were associated with osteoarthritis (knee and hip joints) among men less than 50 years of age (although no relationship was suggested among women or older men).

A number of papers address the more general issue of the relationship between sports participation and health behaviours in young people. Kemper reviews six longitudinal studies of the relationship between the health and fitness of teenagers and sports participation and illustrates that physically active boys and girls have significantly higher VO2 max values than their inactive counterparts, although the conclusion is that higher levels of VO2 cause activity max rather than vice versa. Miller et al (2000) use data from a large-scale survey of school pupils to illustrate that athletic participation has both positive and negative implications for adolescent health and recommend ways to use sport for health promotion. Miller et al (1999), use cultural resource theory to suggest that athletic participation enables girls to resist traditional gender definitions and have lower rates of sexual experience and higher contraception use. For boys, sport seems to reinforce gendered behaviour. Hellansjo et al’s Norwegian survey data indicate that participation in the regulated environment of a sports club may delay the onset of alcohol consumption. Pastor et al use survey data on 15-18 year olds to conclude that the higher the levels of sports participation, the higher the perceived fitness and consequently enhanced perceived health, with lower levels of smoking and alcohol use also enhancing health perceptions. However, the relationships are only weak to moderate. Pyle et al’s survey data on high school students illustrate that, for males and females, competitive sports participation was associated with a lower frequency of mental ill-health, eating and dietary problems and total risks (although there was a higher frequency of sports-related injuries).

Bar-or reviews evidence on the adult health benefits of physical activity in childhood and adolescence and concludes that there is no robust evidence of long-term benefits, although there is some for short-term benefits.

A series of studies address the effects of physical activity on the health of older people. Simonsick et al’s self-assessed longitudinal data illustrate that more rigorous physical activity and a moderately active lifestyle confer some benefits to physically capable older adults, primarily in reducing the risk of functional decline and mortality. Dionne et al’s review, addressing issues of exercise prescription, concludes that improving cardiovascular fitness has a greater impact on a range of health outcomes than simply increasing energy expenditure. Hunter et al’s review concludes that the evidence of the benefits of resistance training in older adults is overwhelming, increasing power, reducing the difficulties of performing daily tasks, enhancing daily energy expenditure and body composition and promoting participation in spontaneous physical activity. Cottreau et al’s survey and interview data conclude that lifetime leisure physical activity was strongly related to decreased risk of ovarian cancer.