Body fat percentage of urban South African children: implications for health and fitness.

OBJECTIVE: To explore gender and racial profiling of percentage body fat of 1136 urban South African children attending public schools in Pretoria Central. METHODS: This is a cross-sectional survey of 1136 randomly selected children (548 boys and 588 girls) aged 9-13 years in urban (Pretoria Central) South Africa. Body mass, stature, skinfolds (subscapular and triceps) were measured. Data were analysed using descriptive statistics (means and standard deviations). Differences in the mean body fat percentage were examined for boys and girls according to their age group/race, using independent t-test samples. RESULTS: Girls had a significantly (p = 0.001) higher percentage body fat (22.7 ± 5.7%, 95% CI = 22.3, 23.2) compared to boys (16.1 ± 7.7%, 95% CI = 15.5, 16.8). Percentage body fat fluctuated with age in both boys and girls. Additionally, girls had significantly (p = 0.001) higher percentage body fat measurements at all ages compared to boys. Viewed racially, black children (20.1 ± 7.5) were significantly (p = 0.010) fatter than white children (19.0 ± 7.4) with a mean difference of 4.0. Black children were fatter than white children at ages 9, 10, 12 and 13 years, with a significant difference (p = 0.009) observed at age 12 years. CONCLUSION: There was a considerably higher level of excessive percentage body fat among school children in Central Pretoria, South Africa, with girls having significantly higher percentage body fat compared to boys. Racially, black children were fatter than white children. The excessive percentage body fat observed among the children in this study has implications for their health and fitness. Therefore, an intervention programme must be instituted in schools to prevent and control possible excessive percentage body fat in this age group.

A prediction equation for the estimation of cardiorespiratory fitness using an elliptical motion trainer.

OBJECTIVE: In the United States of America, 6.2 million individuals are using elliptical motion trainers in fitness centres. However, graded exercise test protocols to estimate peak oxygen consumption (VO(2peak)) using elliptical motion trainers have not been developed for the general population. METHODS: Fifty-nine subjects (mean age: 23.5 +/- 4.1 years) were randomly divided into a validation (VAL: n = 39) or cross-validation (XVAL: n = 20) group. Peak oxygen consumption (ml x kg(-1) x min(-1)) was measured via indirect calorimetry on an elliptical motion trainer for both groups. Subjects exercised at 150 strides x min(-1) against a resistance of four and a crossramp of 8%. The resistance was increased every two minutes by two units until exhaustion. For the VAL group, a stepwise regression analysis was used to predict VO(2peak) from resistance, maximal heart rate (HR(max)), body mass index (BMI), height and gender (female = 0, male = 1). RESULTS: The prediction equation derived from this study was VO(2peak) (ml x kg(-1) x min(-1)) = 187.39403 + 12.97271 (gender) - 1.45311 (height) - 1.21604 (BMI) - 0.19613 (HR(max)) + 1.57093 (resistance) (R2 = 0.76, SEE = 4.47, p < 0.05). Using this equation, the predicted VO(2peak) of the XVAL group was 45.18 +/- 6.42 ml x kg(-1) x min(-1), while the measured VO(2peak) was 43.55 +/- 6.23 ml x kg(-1) x min(-1) CONCLUSION: No significant difference was found between the measured and predicted VO(2peak) in the XVAL group. Therefore, it appears this protocol and equation will allow individuals to accurately estimate their VO(2peak) without using direct calorimetry. However future studies should investigate the validity of this protocol with diverse populations.

Effects of a mat Pilates programme on body composition in elderly women.

BACKGROUND: With ageing, the ability to mobilize fat is reduced and this, coupled with gradual decrease in lean body mass (LBM) from lessened exercise, allows for an increased body fat percentage (%BF). Exercising is considered a key to maintaining an appropriate body mass (BM), as it improves fat oxidation, while maintaining LBM. Although the effects of endurance and/or resistance training on fat mass (FM) and LBM in the elderly have well been established, limited data are forthcoming regarding the effects of Pilates as a training modality on these variables in the elderly. OBJECTIVE: The present study was therefore conducted to determine the effects of a mat Pilates programme on body fat in elderly women. METHODS: Fifty sedentary, apparently healthy females aged 60 years and older were randomly assigned a control (CG, n = 25) or an intervention (IG, n = 25) group. The IG took part in an eight-week progressive mat Pilates exercise programme, three times weekly while the CG were instructed to maintain their normal daily activities throughout the eight-week experimental period. All subjects underwent pre- and post-test in which FM and LBM were assessed. RESULTS: Eight weeks of mat Pilates demonstrated a significant (p ≤ 0.05) decrease in % BF (p = 0.016) and FM (p = 0.038), with a significant increase in LBM (p = 0.006), while not showing any significant changes (p ≥ 0.05) in BM (p = 0.979) and BMI (p = 0.992). The CG, however, did not produce any significant (p ≥ 0.05) changes in any of the tested anthropometric variables (BM: p = 0.266; BMI: p = 0.123; % BF: p = 0.516; FM: p = 0.937 and LBM: p = 0.522) after completion of the eight-week Pilates programme. CONCLUSION: An eight-week mat Pilates exercise programme may contradict or even reverse some of the most serious consequences of ageing associated with an increased fat mass and reduced lean body mass in elderly females.

Stature and body mass of Nigerian children aged 9-12 years.

AIM: Mean stature and body mass at selected ages are useful indices of the health and well-being of children in a community. However, such data is not available in school children in Makurdi, Nigeria. The aim of this paper was to present the stature and body mass of children aged 9-12 years in Makurdi, Nigeria, with a view to providing baseline data for these physical characteristics. METHODS: Anthropometric measurements of stature and body mass were taken in cross-sectional study of 2015 children (979 boys and 1036 girls) randomly selected from 19 public primary schools in Makurdi, Nigeria. RESULTS: The girls (Mean stature=138.9; SD=8.1 cm and body mass: 31.5; SD=6.1 kg) were significantly taller and heavier (P≤0.05) than the boys (Mean stature=137.2; SD=7.7 cm and body mass: 29.8; SD=4.4 kg). At all age categories the girls were taller than the boys. Except at age nine, the girls were significantly heavier than the boys at ages 10 to 12 years (p≤ 0.001). Stature and body mass increased with age in both boys and girls. In comparison with the NCHS growth reference, the Nigerian children were significantly shorter and lighter at all the ages than their American peers. CONCLUSION: Lower values of stature and body mass recorded in this sample in comparison with the NCHS standard are probably due to poor living conditions. Periodic monitoring of these anthropometric indicators in the children could provide reliable data for screening those with growth abnormalities so that appropriate health intervention strategies can be instituted.

Using receiver operating characteristic curve analysis in detecting excess adiposity in 9-13-year old South African children.

OBJECTIVE: Little is known concerning the applicability of receiver operating characteristic (ROC) curve analysis in detecting excess adiposity in preadolescent South African children. Therefore, the purpose of this study was to evaluate the sensitivity and specificity of body mass index (BMI) and skinfold thickness: BMI (subcutaneous to overall fat) in detecting excess adiposity in preadolescent urban South African school children. METHODS: This was a cross-sectional survey of 1136 randomly selected children (548 boys and 588 girls) aged 9-13 years old in urban (Pretoria Central) South Africa. Body mass, stature, skinfolds (subscapular, triceps, supraspinale and biceps) and waist circumference were measured. Receiver operating characteristic curve analysis was used to assess the sensitivity and specificity of BMI, and log10 SF4:BMI to detect excess adiposity. Excess adiposity was defined as levels of log10 SF4 greater than the internally derived 85th percentile (log10 SF4 > 85th percentile). RESULTS: Compared to log10 SF4:BMI, BMI had a high specificity (0.88; 95% CI 0.84, 0.90). The log10 SF4:BMI identified excess adiposity with a sensitivity and specificity of 0.62 (95% CI 0.60, 0.67) and 0.68 (95% CI 0.64, 0.70), respectively. Besides, a decrease in overall misclassification with the use of log10 SF4:BMI instead of BMI at the 95th percentile (9.7% versus 27.1%) was observed. CONCLUSION: Similar to other studies, although with varying degrees, the present study confirms that log10 SF4:BMI at conventional cut-off points has a relatively high sensitivity and specificity in detecting excess adiposity, and therefore could be used to identify the excess adiposity in South African children. As such, defining obesity based on population-specific percentiles rather than using cut-off points derived from other geographical settings with contrasting levels of socio-economic development becomes imperative.

Concurrent training and pulmonary function in smokers.

This study compared the effects of aerobic, resistance and concurrent aerobic and resistance training on pulmonary function and cardiorespiratory endurance in at-risk smokers. 50 sedentary, male smokers with pulmonary function impairments at risk for developing chronic lung diseases were randomly assigned to an aerobic (AerG;n=12), resistance (ResG;n=13), concurrent (ConG;n=13) or non-exercising control (NexG;n=12) group for 16 weeks. AerG subjects performed 45 min of aerobic exercise at 60%HR(max), ResG subjects performed 8 resistance exercises at 60%1-RM for 3 sets, 15 repetitions while ConG subjects performed both aerobic and resistance exercises. ANOVA revealed no significant difference between the groups in their pre-/post-test changes for FEV(1)/FVC ratio (AerG:-4.13%; ResG:-2.13%; ConG:-0.56%); FEF-50 (AerG:-4.59%; ResG:-7.62%; ConG:5.76%), FEF-75 (AerG:-2.36%; ResG:-7.62%; ConG:10.71%) and FEF 25-75 (AerG:-3.53%; ResG:-6.43%; ConG:7.63%). Significant differences were found between the groups in their pre-/post-test changes for FVC (AerG:8.05%; ResG:7.22%; ConG:11.55%), FEV(1) (Aer:9.60%;ResG:5.13%; ConG:12.10%), PEF (AerG: 11.29%; ResG:7.49%; ConG:20.18%), PIF (AerG:24.80%; ResG:19.41%; ConG:28.15%), IVC (AerG: 9.04%; ResG: 6.21%; ConG:16.35%), FEF-25 (AerG:5.88%; ResG:5.37%; ConG:11.88%) and cardiorespiratory fitness (AerG:25.44%; ResG:11.59%; ConG:22.83%). Post-hoc analysis revealed concurrent and aerobic training were equally effective at improving PIF and cardiorespiratory fitness with concurrent training most effective at improving FVC, FEV(1), PEF, IVC and FEF-25. This suggests synergy between aerobic and resistance exercise in preventing or reducing the detrimental effects of smoking while gaining the unique benefits of each mode of exercise.

Concurrent resistance and aerobic training as protection against heart disease.

This study was designed to compare the effects of aerobic and concurrent aerobic and resistance training on their ability to slow the rate of development and progression of coronary heart disease (CHD) in young adult males at low risk, as determined by the Framingham risk assessment (FRA) score. Subjects were assigned to 16 weeks of three-times weekly aerobic training (AT) (n = 13), concurrent aerobic and resistance training (CART) (n = 13) or no exercise (NO) (n = 12). Both AT and CART resulted in significant (p < 0.05) changes in total cholesterol (from 173.67 ± 29.93 to 161.75 ± 26.78 mg.dl(-1) and from 190.00 ± 38.20 to 164.31 ± 28.73 mg.dl(-1), respectively), smoking status (from 12.25 ± 5.08 to 10.33 ± 5.37 cigarettes per day and 12.00 ± 4.71 to 8.77 ± 5.10 cigarettes per day, respectively), high-density lipoprotein cholesterol (from 47.00 ± 11.85 to 57.50 ± 5.99 mg.dl(-1) and 34.00 ± 8.53 to 46.77 ± 14.32 mg.dl(-1), respectively), systolic blood pressure (from 126.17 ± 7.00 to 122.33 ± 3.17 mmHg and 131.54 ± 9.28 to 121.69 ± 7.87 mmHg, respectively) and therefore FRA score (from 3.58 ± 2.19 to 1.33 ± 2.27 and 5.77 ± 3.09 to 2.46 ± 2.90, respectively). Both modes of exercise were found to be equally effective in reducing CHD risk. These findings support the inclusion of resistance training into an aerobic training programme to lower CHD risk, which will afford subjects the unique benefits of each mode of exercise.

Contrasting effects in anthropometric measures of total fatness and abdominal fat mass following endurance and concurrent endurance and resistance training.

An increased total fatness, and especially abdominal fat deposition, is associated with a greater risk for a variety of health problems and metabolic disturbances. It is commonly accepted that endurance training induces the greatest alterations in total adiposity despite resistance training possibly having other advantages on body fat distribution. Thirty-seven males were assigned to 16 weeks of endurance training (ET) (N=12), concurrent endurance and resistance training (CT) (N=13) or no exercise (N=12) to compare the effects of these modes of training on anthropometric measures of fat distribution in previously sedentary males on an Ad Libitum diet. The ET significantly (P

Screening for body-weight disorders in Nigerian children using contrasting definitions.

Several indices for body-weight disorders exist in scientific literature, but it is inconclusive whether or not they can yield comparable results when applied to Nigerian children. The prevalence of weight disorders in Nigerian children was examined using the Centre for Disease Control and Prevention (CDC) body mass index (BMI) for age charts and the International Obesity Task Force's (IOTF) age- and sex-specific BMI cut-off points. Participants were 2015 pupils (979 boys and 1036 girls) aged 9-12 years, attending 19 public primary schools in Makurdi, Nigeria. Stature and body mass were measured using standard techniques. Results were analysed using student t-test and Chi-squared statistics, with the probability level set at

Compatibility of concurrent aerobic and resistance training on maximal aerobic capacity in sedentary males.

Aerobic and resistance training are often performed concurrently by inactive individuals and those patients undergoing cardiac rehabilitation, despite contradictory findings that this mode of training may impair the development of maximal aerobic capacity (VO(2max)). The aim of the study, therefore, was to compare the effects of 16 weeks of aerobic, resistance and concurrent aerobic or resistance training on VO(2max) development. Fifty apparently healthy males (25 years +/- 8 months) were randomly assigned to a non-exercising control group (NonG) (n = 12), an aerobic training group (AerG) (n = 12), a resistance- training group (ResG) (n = 13), or a concurrent aerobic and resistance-training group (ConG) (n = 13). VO(2max) was measured pre- and post-experimentally using a continuous on-line oxygen analyser. Aerobic training consisted of exercise using a combination of treadmills, rowers, steppers and cycle ergometers, whereas resistance training consisted of eight prescribed exercises performed for three sets of 15 repetitions at 60% of the estimated one-repetition maximum (1-RM). In an attempt to equalise exercise duration across all three experimental groups, concurrent aerobic and resistance training consisted of a combination of aerobic training at 60% of heart rate maximum, and resistance training for two sets of 15 repetitions at 60% of the estimated 1-RM. The NonG were found to have decreased their VO(2max) by 3.36%, whereas the ResG increased their mean VO(2max) by 13.16%. The AerG and ConG increased their mean VO(2max) by 34.12 and 29.58%, respectively. In conclusion, concurrent training did not significantly interfere with development of aerobic capacity in sedentary males when compared to aerobic training. Therefore, this investigation did not support the concept of the universal nature of the interference effect that supposes the superiority of a single mode of training.

Relationship between resistance training and lipoprotein profiles in sedentary male smokers.

Epidemiological studies have found plasma lipid and lipoprotein levels to be predictive of cardiovascular disease in adults. To date, regular aerobic modes of exercise have been associated with favourable alterations in lipid and lipoprotein levels. However, the effect of resistance training on lipid and lipoprotein levels is inconclusive and conflicting. Therefore, the aim of this study was to provide some clarity on whether resistance training could be used to improve sedentary male smokers' lipoprotein profiles. The study made use of a pre-test, a treatment period and a post-test. Subjects were placed into one of two groups, namely, a resistance-training (RES) group (n = 13) or a control (CON) group (n = 12). Throughout the 16-week experimental period the CON group received no treatment whatsoever. After resistance training, serum triglyceride levels were significantly decreased by 18.42% from 1.162 mmol/l (+/- 0.476) to 0.831 mmol/l (+/- 0.058) (p = 0.038) in the RES group. However, resistance training was found to have no impact on any of the other measured lipid and lipoprotein measures. In conclusion, these findings indicate that resistance training appears to have no significant effect on lipid and lipoprotein profiles in sedentary male smokers and therefore cannot prevent the advance of CAD.

Consequence of resistance training on body composition and coronary artery disease risk.

Coronary artery disease (CAD) is a substantial cause of death and disability in South Africa and Western society, with research showing obesity to be one of the most common CAD risk factors. Furthermore, obesity is speculated to be the fastest-growing CAD risk factor and to become the most prevalent CAD risk factor. Research on obesity is therefore essential, and we propose some preventative measures that will hopefully limit the expansion of this risk factor for CAD. Most of the literature has focused primarily on aerobic modes of exercise. The aim of this study, therefore, was to investigate whether resistance training would improve body composition. Twenty-eight males were matched by age, percentage of body fat and waist-to-hip ratio and randomly assigned either to a resistance-training group (n = 13) or a control group (n = 15). Each subject's body mass, percentage body fat, lean mass, fat mass, waist-to-hip ratio and body mass index were assessed both pre- and post-experimentally following the eight-week experimental period. The resistance-training group trained three times weekly at 60% of their one-repetition maximum using nine resistance exercises. Each exercise was performed for three sets of 15 repetitions each, whereas the control group did not exercise over this period. The dependent t-test indicated that resistance training significantly changed body mass, percentage of body fat, lean mass and fat mass (all had a p-value of 0.00; p

Effect of resistance training on cardiorespiratory endurance and coronary artery disease risk.

Coronary artery disease (CAD) represents a major medical problem in Western society and is a considerable cause of morbidity and mortality in South Africa. In recent years, epidemiologists have made extensive efforts to define the most common risk factors for CAD and propose preventative measures to limit the spread of the disease. Despite the increasing realisation of the importance of resistance training, the literature has focused primarily on aerobic modes of exercise and their effects on risk for CAD. The aim of this study was to determine whether resistance training could alter cardio-respiratory endurance (VO2max), and thus reduce CAD risk. A quantitative, experimental, comparative research design incorporating a pre-test, a treatment period and a post-test was used. Twenty-eight untrained male volunteers were age matched (mean age: 28 years and seven months) and randomly assigned to either a nonexercising control group (n = 15) or a resistance-training group (n = 13). The study demonstrated no statistically significant change in VO2max for the control group from their pre-test (25.097 ml/kg/min) to their post-test (23.778 ml/kg/min) (p = 0.201). However, resistance training significantly (p

An evaluation of three techniques improving immunization levels in elementary schools.

Three techniques for improving immunization levels among school-age children were tested and then compared for most effective use of school nurses' time. Method A involved reviewing school immunization records, specifically inviting immunization-deficient children to a school-based clinic, with some follow-up to achieve good response. Method B involved sending out permission slips for a school-based clinic to all students without additional investment of nursing time. Method C involved a health education program encouraging parents to have their children immunized on their own. Using an average of 38 hours of school nurse time, Method A succeeded significantly better then Method B in immunizing more immunization-deficient children and raising immunization levels , while giving fewer unnecessary immunizations. Method C did not produce significant improvement of immunization levels.