Inactivity has been linked to the development of chronic diseases (Westernerp, 1999; Grund et al., 2001). While physical activity is been considered as a modifiable factor for preventing and reducing mortality from many chronic diseases of lifestyle (National Institutes of Health, 1996; US Department of Health and Human Services, 1996; Bauman & Owen,1999). In addition it is been suggested that people who are regularly active are more advantaged than the sedentary one’s with regard to development of chronic diseases (Powell, 1997). Regular physical activity is linked to enhanced health and to reduced risk for all-cause mortality and the development of many chronic diseases (US Department of Health and Human Services, 1996). Furthermore, participation in physical activity provides people with substantial physical, social and mental health gains and well-being throughout the entire lifespan (Gallahue & Ozmun, 1995).

Physical fitness is the maintenance of basic body functions to get through day-to-day activities around the work place and the house. Cardiorespiratory endurance, or the body capacity to use oxygen efficiently, is often considered the most important health-related component of physical fitness (Malina, 1997). Research findings suggested that cardiorespiratory activity can reduce the risk or alleviate the symptoms of cardiovascular disease, obesity, hypertension, high blood cholesterol, and diabetes (Blair et al., 1989; Pate et al., 1995; National Institutes of Health, 1996; US Department of Health and Human Services, 1996; Williams, 2001).

In answering the research question raised in this review a literature search was performed with the aid of computer through Medline, PUBMED search performed on 18 April 2006, using physical fitness and physical activity as key words. Further, studies included were restricted to those studies which deal with children (i.e. covering the age range from 5 to 14 years) on the relationship between physical fitness and physical activity. The included studies were mostly on cross-sectional design. Eight out of 11 found published studies which were relevant and were included in the review (Table 1). The excluded studies were based on the associations between nutrition or growth, fatness and physical fitness and physical activity or vice versa, or children older than the one included in the selection criteria. Furthermore, some investigating the role of physical activity in obesity/overweight.

In contrary to what was postulated by Livingstone (1994) that it is obvious that activity and fitness are strongly related the reviewed studies showed few relationships (Table 1). In South Africa, the cross-sectional findings in 212 boys and girls aged 7-14 year old from the Ellisras Longitudinal Study (Monyeki et al., 2000) showed few significant relationships between physical activity and sit-ups, shuttle run and 1600m run in girls, but none in boys (Monyeki et al., 2005). Further, in Senegal Benefice (1992; 1998) reported low relationships between estimated activity and motor fitness variables. In addition Benefice’s study showed gender differences in the relationship between cardiorespiratory fitness and activity in girls, but not in boys. Furthermore, similar results were also found in a study that was done in Mozambique, where it was reported that total physical activity was significantly associated with cardiorespiratory endurance run (Prista et al., 1997).In Taiwane youth 12-14 years of age, estimated energy expenditure in moderate-to-vigorous physical activity was significantly related to the one-mile run and sit-and-reach, but was not related to sit-ups and the sum of skinfolds. After controlling for age, sex, socio-economic status and area of resident, though not significant, were low, 0.12 to 0.19, and the amount of variance accounted for was <5% (Haung and Malina, 2002). Estonian children, few significant relationships between fitness and activity were observed after the correction for age, height and weight (Oja & Jürimäe, 1998). Such relationships were found between activity, plate tapping, flamingo balance, standing broad jump, bent arm hang, handgrip, endurance shuttle run for boys and girls separately.

In Kiel (Germany), a study by Grund et al. (2000) which investigated the relationships between physical activity, physical fitness, muscle strength and nutritional state in 88 children 5- to 11-year-old revealed no association between energy expenditure and activity with aerobic fitness.

In Bangor, North Wales, Rowlands and colleagues (1999) in their study which investigated the relationship between habitual daily activity and levels of body fatness and aerobic fitness in 8- to 10-year-old children. In their study significant relationship between aerobic fitness (endurance run on a treadmill) and activity (Tritrac and pedometer) was found.

The outcomes of this review study were in contrast with observed strong relationship found in adults’ studies on the relationship between physical fitness and physical activity. This may however be a major concern for public health and human movement science professionals, and therefore appeal for further investigation in the relationship between physical fitness and physical activity over a period of time. Criticism made by Malina (1997) are that the physical education profession should start to shift emphasis on sport skills and do much on health-related physical fitness such as cardiorespiratory fitness, muscle and power strength. The stated criticism may seem to be relevant for the findings in this review. Moreover, many involved in public health or the health promotion field hold that cardiorespiratory endurance and fitness should be the objective of physical education at all grade levels, particularly in the context of the goals of the Healthy People 2000 (U.S. Public Health Service, 1990).

Todate, few studies have examined the relationship between activity and fitness particularly in developing countries like South Africa. Therefore, more studies from different cultural background including Ellisras Longitudinal Study with the emphasis on longitudinal design are needed to confirm or refute the discrepant findings regarding physical fitness and physical activity in children. In addition to activity questionnaire, there is also a need to employ some sophisticated methods of assessing physical activity in children in order to draw a clear conclusion on (1) the relationship between physical fitness and physical activity in children and (2) to unravel the causality of this relationship with randomized control trials with physical activity as the independent and physical fitness as the dependent variable.