HIV prevention through sport: the case of the Mathare Youth Sport Association in Kenya.

Sport has become a popular tool for HIV prevention, based on claims that it can foster life skills that are necessary to translate knowledge, attitudes and behavioural intentions into actual behaviour. Empirical evidence of the effectiveness of sport-based HIV prevention programmes is, however, sorely lacking. We therefore conducted a cross-sectional survey assessing sexual behaviour and the determinants thereof among 454 youth of the Mathare Youth Sport Association (MYSA) in Kenya and a control group of 318 non-MYSA members. Multiple (ordinal) logistic regression models were applied to measure the association between MYSA membership and attitudes, subjective norms and self-efficacy related to condom use as well as sexual experience, age at sexual debut, condom use, history of concurrent relationships and number of partners in the last year. MYSA members were more likely to use condoms during the first sex act (odds ratio (OR)=2.10; 95% CI: 1.10-3.99). Consistent condom use with the current/last partner was 23.2% (36/155) among MYSA members vs. 17.2% (17/99) among the control group. Even after adjusting for media exposure - a factor associated with both MYSA membership and higher frequency of condom use - MYSA members were still found to use condoms more frequently with their current/last partner (adjusted OR=1.64; 95% CI: 1.01-2.68). Nevertheless, levels of condom use remain disturbingly low. More rigorous evaluations of sport programmes for HIV prevention are needed. When possible, programmes should be preceded by baseline assessments, trends in risk behaviour of the intervention group should be compared with those of a control group, and protocols for data collection and analysis should include measuring of and adjusting for potentially confounding factors.

Methodological issues associated with longitudinal research: findings from the Leuven Longitudinal Study on Lifestyle, Fitness and Health (1969 - 2004).

Longitudinal studies provide unique opportunities but are also faced with several limitations. The purpose of this study was to document three of these issues ("imperfect" design, evolution of data collection methods, representativeness) by means of the Leuven Longitudinal Study on Lifestyle, Fitness and Health (LLSLFH). The LLSLFH (1969 - 2004) comprises observations on males between 12 and 18 years and at 30, 35, 40, and 47 years, and on females at 16 and 40 years. In the most recent phase of the study, spouses and offspring were also included. The different phases and evolving research questions throughout the LLSLFH required an appropriate adaptation of the research design. The associated evolution of data collection methods largely reflects the changing ideas about physical fitness, body composition, and physical activity, the continuing search for new and better measurement techniques, and the need for adaptations with age. Ongoing study participants are representative in terms of body composition and, except for adolescence in males, also physical activity. No straightforward answer can be given concerning physical fitness. In both sexes, socio-economic status is above average. When informed about the possible "pitfalls" of longitudinal research in advance, several measures could be taken to prevent or limit them as much as possible.

Tracking of physical fitness and physical activity from youth to adulthood in females.

PURPOSE: To evaluate stability of physical fitness and physical activity from adolescence into middle adulthood in Flemish females. METHODS: Within the scope of the Leuven Longitudinal Study on Lifestyle, Fitness and Health, 138 females (mean age=16.6+/-1.1 yr) from the Leuven Growth Study of Flemish Girls were seen in adulthood (mean age=40.5+/-1.1 yr). Several body dimensions and motor fitness tests were taken. Physical activity was assessed by means of a sports participation inventory. Inter-age correlations were calculated between adolescent and adult values. Cross-tabulation was used to identify the percentage of subjects remaining in the same BMI and physical activity group or shifting from one group to another from adolescence to adulthood. Odds ratios for less activity and overweight in adulthood according to adolescent activity or weight status were calculated. RESULTS: Except for flamingo balance, plate tapping, leg lifts, and arm pull, all anthropometric and physical fitness characteristics were stable from adolescence to adulthood (r ranging from 0.49 to 0.96). Sports participation was not a stable characteristic (r=0.13). From adolescence to adulthood, 84.5 and 63.6%, respectively, remained in the normal-weight and overweight group, whereas 62.5 and 54.4%, respectively, remained in the less active and active group. The odds of being overweight in adulthood was 9.53 (95% CI: 3.1-29.8) times greater in overweight compared with normal-weight adolescent girls. CONCLUSION: In Flemish females, anthropometric and fitness characteristics demonstrate higher levels of stability from adolescence to middle adulthood than physical activity. Weight status during adolescence is indicative of adult weight status, and a pattern of less activity rather than activity tends to continue from youth to adulthood.

Adolescent correlates of adult physical activity: a 26-year follow-up.

PURPOSE: It is hypothesized that adolescent physical activity, fitness, anthropometric dimensions, fatness, biological maturity, and family characteristics contribute to the variation in physical activity at 40 yr of age, and that these associations vary with age. METHODS: Subjects were 166 males followed from 1969 to 1996, between the ages of 14 and 40 yr from the Leuven Longitudinal Study on Lifestyle, Fitness and Health. Sports participation, fitness, anthropometric dimensions, fatness, and biological maturity were observed during the growth period. Also, sociocultural characteristics of the family were examined. The work, leisure time, and sport activity index of the Baecke Questionnaire and activity counts of a triaxial accelerometer were used as outcome variables at 40 yr. RESULTS: When upper and lower activity groups (quintiles) at 40 yr were contrasted, moderate associations were found (R2c varied between 0.1419 and 0.3736). No or low associations were found with the leisure time index. Body dimensions, fitness scores, sports practice, and family characteristics contributed to the explained variance in work, sport index, and activity counts. Multiple correlations were low (R2 = 0.037-0.085) for the work and leisure time activities, and were somewhat higher (R2 = 0.06-0.156) for the sport index and the activity counts in the total sample. CONCLUSION: Adolescent somatic dimensions, fitness, sports participation, parental sociocultural characteristics, and sport participation contributed to a small-to-moderate extent to the contrast between high and low active adults.

Influence of participation in high-impact sports during adolescence and adulthood on bone mineral density in middle-aged men: a 27-year follow-up study.

This study examined whether participation in high-impact sports during adolescence and adulthood contributes to bone health in males aged 40 years. Data were analyzed on 154 Belgian men aged 13 years at study onset in 1969 and aged 40 years at the end of the 27-year follow-up. In a second analysis, subjects were divided into three groups according to their sports participation history: participation during adolescence and adulthood in high-impact sports (HH; n=18), participation during adolescence in high-impact sports and during adulthood in nonimpact sports or no sports (HN; n=15), and participation during adolescence and adulthood in nonimpact sports or no sports (NN; n=14). Body mass and impact loading during adulthood were significant predictors of total body bone mineral density (BMD) and lumbar spine BMD. Analysis of variance revealed significant differences for lumbar spine BMD between the HH (1.12 g/cm2) group and the HN (1.01 g/cm2) and NN (0.99 g/cm2) groups (F=5.07, p=0.01). Total body BMD was also higher in the HH group at age 40 years, but not significantly (F=3.17, p=0.0515). Covariance analyses for total body BMD and lumbar spine BMD, with body mass and time spent participating in sports as covariates, confirmed these results. Continued participation in impact sports is beneficial for the skeletal health of males aged 40 years.

Modeling stability and change in strength development: a study in adolescent boys.

The purpose of this study was to investigate stability and change in different expressions of strength development in adolescent boys using structural equation modeling. Three models were used: Markov simplex to study stability or tracking, Wiener or random walk to investigate fanning-out or spread effects in change, and latent growth to study differences in individual pathways of change as well as group changes. In the Leuven Growth Study, 588 male subjects were followed for 6 years with a mean age of 12.7 years at the onset of the study. Vertical jump, arm pull, and bent arm hang were used to mark the following strength factors: explosive strength, static strength, and functional strength. All models were tested with robust estimation procedures based on the software EQS 6.0. Main results and conclusions are as follows: 1) all strength factors showed moderate to high tracking, with low values of instability in relative position of the subjects in their developmental channels; 2) the fanning-out effect is not obvious, although some evidence showed a spread effect in functional and explosive strength; 3) there are marked interindividual differences in developmental pathways of strength manifestations; 4) strength development is linear and also has some curvilinearity, something akin to a breaking effect; 5) linear trend is negatively correlated with initial status and the leveling-off effect is also negatively correlated with the linear change.

Daily physical activity and physical fitness from adolescence to adulthood: A longitudinal study.

The stability of physical fitness and physical activity in Flemish males from 18 to 40 years of age was investigated. In addition, effects of a consistently low-activity or high-activity level during the same age period on physical fitness were studied. The sample consisted of males who were followed longitudinally from age 13 to age 18 years, and were remeasured at the ages of 30, 35, and 40 years. Complete data about physical fitness and physical activity between 13 and 40 years were available for 130 subjects. Stability was measured using Pearson autocorrelations and simplex models. Multivariate analysis of variance (MANOVA) for repeated measurements was used to look for the effects of activity level on physical fitness. Simplex models showed higher stability coefficients than Pearson correlations, and stability of physical fitness was higher than stability of physical activity. Physical fitness showed the highest stability in flexibility (r = 0.91 between 18 and 30 years, r = 0.96 for both the 30-35 and 35-40 ages intervals), while physical activity showed the highest stability during work (r between 0.70 and 0.98 for the 5-year intervals). Results from MANOVA indicated that for some fitness characteristics the high-active subjects were more fit than their low-active peers. Stability of physical activity was higher than assumed and, therefore, it is a useful and independent indicator for further research. Although possible confounding factors are present (e.g., heredity), a higher level of physical activity during work and leisure time on a regular basis benefits physical fitness considerably. Am. J. Hum. Biol. 12:487-497, 2000. Copyright 2000 Wiley-Liss, Inc.

Associations between daily physical activity and physical fitness in Flemish males: A cross-sectional analysis.

The relationship of physical activity to several components of physical fitness was investigated in a sample of 166 males 40 years of age. In addition to Pearson correlations, multivariate canonical correlations were calculated. Physical activity during work (work index), sport (sport index), and leisure time (leisure time index) was assessed by the Baecke questionnaire. Physical fitness included cardiorespiratory fitness measures, the body mass index (BMI), the sum of seven skinfold thicknesses (SKI), percentage body fat (PFAT), balance, and several tests of muscle strength and endurance, flexibility, and speed of limb movement. More than 86% of the variance was shared by the two first canonical variables. The first canonical variable can be interpreted as a health-related fitness function. Carciorespiratory fitness, balance, speed of limb movement, explosive strength, and trunk muscle strength are clearly related to this function. From the physical activity measures, the Baecke sport index correlated significantly with this health-related fitness function. The second canonical variable can be explained as a fatness function, since body weight, BMI, SKI, and PFAT showed the highest correlations with the variable. The Baecke work index was inversely related to this canonical variable. The sample was also divided into physical activity groups in order to look for differences in physical fitness. The data indicate that physical activity during work was modestly, but inversely related to adiposity. Sport activity was beneficially associated to several fitness components, including cardiorespiratory fitness, trunk muscle strength, and upper body muscular endurance. Am. J. Hum. Biol. 11:587-597, 1999. Copyright 1999 Wiley-Liss, Inc.

Sociogeographic variation in the physical fitness of a cross-sectional sample of Flemish girls 13 to 18 years of age.

Three aspects of physical fitness-somatic characteristics, motor fitness, and sport participation-of girls from different sociogeographic origins of Belgium were contrasted. The sample consisted of a cross-sectional sample of 4,528 Flemish girls 13 to 18 years of age, who were classified by dwelling area as rural, semi-urban, and urban. Somatic characteristics included 16 anthropometric dimensions, skeletal maturity, and somatotype. Motor fitness was assessed by 10 tests. Sociocultural background information and the level of sport participation were investigated by questionnaire and interview. Data were analysed via one-way analyses of variance and growth curves were plotted to compare the sociogeographic differentiation patterns in physical fitness variables. The results show small motor and somatic differences between rural and urban youngsters, which is explained by the process of conurbation. However, urban girls were significantly more involved in sports than their rural counterparts. This is most probably due to greater sport involvement of parents from urban girls and/or the differences in available sport facilities.