Dietary supplements and beverages: Knowledge, attitudes, and practices among semi-professional soccer players in KwaZulu-Natal, South Africa.

Background: The ingestion of dietary supplements and beverages is prevalent in soccer, at the amateur and professional level. The absence of professional advice at non-professional level makes amateur soccer players susceptible to ingesting unsafe supplements. Objectives: To determine the knowledge, attitudes and practices of ABC Motsepe League (semi-professional) players in KwaZulu-Natal regarding the use of dietary supplements and beverages. Methods: Three hundred and forty-three soccer players participated in a cross-sectional study. Knowledge, attitudes and practices were determined using a questionnaire. Researchers visited twelve teams. On the day of the visit to each team, information sheets and questionnaires were given to participants. Questionnaires were collected immediately following completion. Descriptive statistics were used, including means and standard deviations, where applicable. Inferential statistics, Chi-square and binomial tests were used to analyse the results. Statistical significance was set at p < 0.05. Results: Sports beverages were the most recommended and commonly used, followed by energy beverages. Dietary supplements were the least-known used. Participants used beverages and dietary supplements to assist in providing more energy (67%), improve health (65%) and improve performance (55%) (p<0.001). Seventy-three percent of participants lacked knowledge about the anti-doping policy (p<0.001), with 87% having never attended a workshop on the safe use of supplements and beverages, or anti-doping awareness campaigns (p<0.001). Thirty-eight percent had not heard of the South African Institute for Drug-Free Sport (SAIDS), and 84% were not familiar with the yearly updated World Anti-Doping Agency's (WADA) prohibited list (p<0.001). Of the 59% who did not take dietary supplements or beverages, 75% had insufficient information regarding them (p<0.001), 66% indicated that dietary supplements and beverages were costly (p=0.001), and 55% indicated they did not need dietary supplements and beverages (p=0.32). Conclusion: There is a need for an educational programme on the safe use of dietary supplements, and sports and energy beverages among KwaZulu-Natal semi-professional soccer players.

Physical activity levels in urban-based South African learners: A cross-sectional study of 7 348 participants.

BACKGROUND: Establishing profiles of physical activity (PA) is critical in tackling the chronic diseases associated with lack of PA and avoiding healthcare costs. OBJECTIVE: To investigate PA levels in urban-based South African (SA) primary school learners. METHODS: The Physical Activity Questionnaire for Older Children was completed by 7 348 learners (3 867 males and 3 481 females) aged 8 - 14 years, of whom 49% were white, 39% black and 12% from other ethnic groups. Differences in PA levels by ethnic origin and province were determined using an analysis of covariance after adjusting for gender (p<0.05). Bonferroni corrections controlled for multiple comparisons. A fitted regression model examined age-related differences in PA adjusting for province. RESULTS: Of SA learners aged 8 - 14 years, 57% (n=4 224) engaged in moderate levels of PA. Thirty-one percent (n=2 247) did not meet internationally recommended amounts of moderate to vigorous physical activity. Overall, males reported higher PA levels than females (p<0.0001). PA levels declined with age from 11 to 14 years by 14% and 20% in males and females, respectively. Black learners had higher PA levels than white learners (p=0.0039). There were also significant differences in PA levels between the provinces (p<0.0001). CONCLUSION: This study provides evidence of differences in PA levels between gender, age and ethnic groups, and between provinces. A targeted approach to increase PA in high-risk populations in SA is warranted. Increased PA will help reduce the risk of chronic diseases and will contribute to the health of SA's population and the growth of the country's economy.

Early prenatal androgen exposure reduces testes size and sperm concentration in sheep without altering neuroendocrine differentiation and masculine sexual behavior.

Prenatal androgens are largely responsible for growth and differentiation of the genital tract and testis and for organization of the control mechanisms regulating male reproductive physiology and behavior. The aim of the present study was to evaluate the impact of inappropriate exposure to excess testosterone (T) during the first trimester of fetal development on the reproductive function, sexual behavior, and fertility potential of rams. We found that biweekly maternal T propionate (100 mg) treatment administered from Day 30-58 of gestation significantly decreased (P < 0.05) postpubertal scrotal circumference and sperm concentration. Prenatal T exposure did not alter ejaculate volume, sperm motility and morphology or testis morphology. There was, however, a trend for more T-exposed rams than controls to be classified as unsatisfactory potential breeders during breeding soundness examinations. Postnatal serum T concentrations were not affected by prenatal T exposure, nor was the expression of key testicular genes essential for spermatogenesis and steroidogenesis. Basal serum LH did not differ between treatment groups, nor did pituitary responsiveness to GnRH. T-exposed rams, like control males, exhibited vigorous libido and were sexually attracted to estrous females. In summary, these results suggest that exposure to exogenous T during the first trimester of gestation can negatively impact spermatogenesis and compromise the reproductive fitness of rams.

Autonomic cardiac regulation, blood pressure and cardiorespiratory fitness responses to different training doses over a 12 week group program in the elderly.

AIM: The study assessed the effects of different weekly training frequencies performed over a 12 week exercise programme (strength, endurance, balance) on autonomic cardiac activity, blood pressure and cardiorespiratory fitness (CRF) in elderly individuals. METHODS: Fifty-eight individuals participated in the study: 2TG (N=24, 71.1±6.4 yrs; 19 females, 5 males) performing two, 60min sessions/week; and 3TG (N=34, 72.3±7.9 yrs; 25 females, 9 males) performing three, 60min sessions/week. Time domain and spectral analysis of heart rate variability (HRV) quantified autonomic cardiac regulation. RESULTS: Natural logarithm (Ln) transformation was applied to all HRV parameters. There were significant reductions in total power (Ln TP) (p=0.006), low frequency (Ln LF) (p=0.013), high frequency (Ln HF) (p=0.013) and root mean square of successive differences (Ln rMSSD) (p=0.014) post training in 3TG after intervention. Diastolic BP (DBP) decreased significantly in both groups (2TG: P<0.001; 3TG: P<0.001). Both groups showed significant improvements in six-minute walk distance (2TG: P=0.003, 3TG: P=0.001). However, there were significant HRV differences between 2TG and 3TG for Ln TP (P=0.018), Ln LF (P=0.049), Ln HF (P=0.039) and Ln rMSSD (P=0.049). CONCLUSIONS: A combined exercise programme resulted in improved DBP and CRF irrespective of training two or three 60min sessions/week. However, training three, sessions/week induced negative health-related changes in autonomic cardiac activity through reducing HRV parasympathetic function, while HRV was maintained in the group training twice a week.

Change in performance in response to training load adjustment based on autonomic activity.

The primary aim of this study was to assess performance (Perf) changes in response to a new training strategy. Specifically, based on spectral analysis of heart rate variability (SA HRV) to determine autonomic nervous system (ANS) activity, training doses were adjusted to maintain vagal activity at a high and relatively stable level during training preparation. Trained athletes (5 male and 5 female) aged 23.2±4.2 years voluntarily participated in the study. ANS activity was assessed during an orthoclinostatic test, and was represented by calculating HRV variables and a total score index. Over 17 weeks, improvement (1.4-8.5%) and deterioration (0.1-8.8%) in Perf were detected in 7 and 3 athletes, respectively. A relationship (rs=0.684; P<0.05) between the change in Perf (ΔPerf) and supine PHF during season was found. Supine HRV indices (PHF, PT, and MSSD) for the last 3 weeks of the HRV-adjusting period correlated (rs=0.636; 0.648; 0.648, P<0.05) with ΔPerf. Based on the results, a high and relative stable vagal activity during preparation may indicate a readiness to train or appropriate recovery that positively affects Perf. In conclusion, daily quantification of ANS activity by SA HRV seems to be a promising tool for the enhancement of Perf.

Elevated salivary C-reactive protein predicted by low cardio-respiratory fitness and being overweight in African children.

INTRODUCTION: C-reactive protein (CRP) is a sensitive marker of systemic inflammation and is an independent risk factor for cardiovascular disease. The aim of the study was to examine the relationship between salivary CRP, cardio-respiratory fitness and body composition in a paediatric population. METHODS: This was a cross-sectional study of 170 black South African children (age 9.41 ± 1.55 years, 100 females, 70 males) in grades 3 to 7. Unstimulated whole saliva samples were obtained for the analysis of CRP. Height, mass, skin-fold thickness, resting blood pressure, and waist and hip circumference measurements were obtained. Cardio-respiratory fitness was assessed using a 20-m multi-stage shuttle run. Children were classified as overweight/obese according to the Center for Disease Control and Prevention (CDC) body mass index (BMI) percentile ranking, and meeting percentage body fat recommendations, if percentage body fat was ≤ 25% in boys and ≤ 32% in girls. The cut-off point for low cardio-respiratory fitness was a predicted aerobic capacity value ≤ the 50th percentile for the group. Contributions of low cardio-respiratory fitness, overweight/obesity, and not meeting percentage body fat recommendations, to elevated salivary CRP (≥ 75th percentile) concentration and secretion rate were examined using binary logistic regression analysis with a backward stepwise selection technique based on likelihood ratios. RESULTS: Poor cardio-respiratory fitness was independently associated with elevated salivary CRP concentration (OR 3.9, 95% CI: 1.7-8.9, p = 0.001). Poor cardio-respiratory fitness (OR 2.7, 95% CI: 1.2-6.1, p = 0.02) and overweight/obesity (BMI ≥ 85th percentile) (OR 2.5, 95% CI: 1.1-5.9, p = 0.03) were independent predictors of elevated salivary CRP secretion rate. CONCLUSION: The results suggest a strong association between poor cardio-respiratory fitness and/or overweight/obesity and inflammatory status in children, based on elevated salivary CRP levels.

Sport stacking in auditory and visual attention of grade 3 learners.

The effect of sport stacking on auditory and visual attention in 32 Grade 3 children was examined using a randomised, cross-over design. Children were randomly assigned to a sport stacking (n=16) or arts/crafts group (n=16) with these activities performed over 3 wk. (12 30-min. sessions, 4 per week). This was followed by a 3-wk. wash-out period after which there was a cross-over and the 3-wk. intervention repeated, with the sports stacking group performing arts/crafts and the arts/crafts group performing sports stacking. Performance on the Integrated Visual and Auditory Continuous Performance Test, a measure of auditory and visual attention, was assessed before and after each of the 3-wk. interventions for each group. Comparisons indicated that sport stacking resulted in significant improvement in high demand function and fine motor regulation, while it caused a significant reduction in low demand function. Auditory and visual attention adaptations to sport stacking may be specific to the high demand nature of the task.

Effect of short-term isometric handgrip training on blood pressure in middle-aged females.

OBJECTIVE: To determine the effect of isometric handgrip training on blood pressure (BP) in middle-aged women (47.88 ± 1.8 years). METHODS: Isometric handgrip training was performed over five consecutive days. In each session, the treatment group (n = 9) performed four isometric contractions of 45 seconds each at 30% of their maximal grip strength. The control group (n = 9) sat for 15 minutes without exercising, for five consecutive days. Resting systolic (SBP) and diastolic blood pressure (DBP) were measured pre- and post-intervention. Data were analysed using a two-factor ANOVA (p ≤ 0.05). RESULTS: Blood pressure readings were reduced in both groups (SBP: p = 0.036; DBP: p = 0.0079), however there was no interaction effect for SBP or DBP. CONCLUSIONS: The findings suggest that 15 minutes of sitting per day for five consecutive days is just as effective as isometric handgrip training for reducing BP levels. Future research is required to investigate the optimal isometric handgrip training stimulus required to reduce resting BP levels.

Changes in Neutrophil Count; Creatine Kinases and Muscle Soreness after Repeated Bouts of Downhill Running

OBJECTIVE. A primary objective was to examine circulating neutrophil count after repeated bouts of downhill running. An additional aim was to determine creatine kinase (CK)levels during the initial 12 hours; after repeated DHRs. DESIGN. Eleven healthy; untrained Caucasian males performed 2 x 60 min bouts of DHR (-13.5); spaced 14 days apart; at a speed equal to 75VO2max on a level grade. Blood was collected before; after; and every hour for 12 hours; and every 24 hours for 6 days. Absolute neutrophil count; CK; and delayed-onset muscle soreness (DOMS) were assessed. Result were analysed using repeated measures ANOVA (p0.05) with appropriate post hoc tests. RESULT. There were no significant differences in neutrophil count (p

Immunoglobulin responses to a repeated bout of downhill running.

OBJECTIVE: To examine the effect of downhill running on immunoglobulin responses. METHOD: Eleven untrained men performed 2 x 60 minute bouts of downhill running (-13.5% gradient), at a speed eliciting 75% of their vO2peak on a level grade. Two runs were spaced 14 days apart. Serum samples were collected before, after, and every hour for 12 hours and every 24 hours for six days. Serum total creatine kinase and immunoglobulin isotypes and subclasses were measured, and results were analysed using a repeated measures analysis of variance (12 hour period, 2 x 14; 24 hour intervals, 2 x 6, p < or = 0.05). RESULTS: There was a significant interaction effect for creatine kinase (activity lower after run 2 than after run 1, 6-24 h) and exercise effect, with the serum concentrations of IgG1, IgG2, IgG4, and IgE lower, and IgM higher, after run 2. CONCLUSION: Lower concentrations of IgG1, IgG2, and IgE after run 2 may reflect a dampened autoimmune inflammatory response to autoantigens and enhanced autoantigen clearance mediated by the upregulation of IgM.

Changes in mucosal and humoral atopic-related markers and immunoglobulins in elite cyclists participating in the Vuelta a España.

Atopic-related factors, humoral and mucosal immunoglobulins (Ig), and cortisol were measured in 17 professional cyclists competing in the 2003 Vuelta a España (a three-week multi-stage race). Venous blood and saliva samples were obtained the morning before the start of the race (T0), on the first rest day after 10 days of racing (T1), and before the start of the last stage after 21 days of racing (T2). Atopic-related factors, IgE, eosinophil cationic protein (ECP), and eosinophils, were significantly altered during the race. Serum IgE (T1: + 10 %) and ECP (salivary, T1: 113 % and serum, T2: 155 %) were significantly increased, while eosinophils (T1: - 32 %, T2: - 55 %) were significantly lower, than pre-race levels. Salivary sIgA secretion rate was significantly decreased at T2 (- 36 %). Pearson product-moment correlations revealed a modest correlation between salivary sIgA and salivary ECP (T1: r = 0.30; T2: r = 0.48; p < 0.01). Serum IgM, total IgG, IgG1, IgG2, IgA levels, at T1 and T2, and cortisol at T2, were significantly lower than pre-race levels. In conclusion, the elevation in IgE and ECP suggests an up-regulation of atopic-related factors in professional cyclists participating in the Vuelta a España. The correlation between salivary sIgA and salivary ECP indicates a role for sIgA in mediating mucosal inflammation. The alterations in Ig levels may indicate Ig isotype switching. An increasing state of hormonal fatigue may have influenced the observed immune alterations.

Serum concentrations of C reactive protein, alpha1 antitrypsin, and complement (C3, C4, C1 esterase inhibitor) before and during the Vuelta a Espana.

OBJECTIVES: To determine serum concentrations of proinflammatory (C reactive protein, complement C3 and C4) and anti-inflammatory (alpha(1) antitrypsin, C1 esterase inhibitor (C1-INH)) acute phase proteins in elite cyclists before and during a three week cycle tour. METHODS: Seventeen professional cyclists participating in the Vuelta a Espana volunteered for the study. Their mean (SD) physical characteristics were: age 28 (1) years; height 1.7 (0.06) m; weight 65 (7) kg; body fat 7.6 (0.8)%; Vo(2)max 75.3 (2.3) ml/kg/min. Venepuncture was performed on each subject 24 hours before the tour began (T0), on day 11 (the first rest day; T1) and day 21 (the second to last stage of the tour; T2). Samples at T1 and T2 were taken about 17 hours after the previous stage. Analysis of variance was used to determine changes over time. Where significance was found, a Tukey post hoc test was performed. RESULTS: C reactive protein concentrations were consistently within the normal range, although there was a 228%, non-significant increase at T1. C3 concentrations fell within the normal range at all times assessed. C4 concentrations before the race were within the normal range and were significantly increased 10 days (T1) into the race. C1-INH concentrations did not change significantly throughout the race. alpha(1) Antitrypsin concentration before the race was at the lower end of the normal range and was only significantly raised at T2. CONCLUSIONS: Although not as pronounced as those reported in marathon/ultramarathon runners, elite cyclists participating in a three week cycle tour experienced increases in selected proinflammatory and anti-inflammatory acute phase proteins, indicating an acute phase/inflammatory response. It is tenable that the increase in alpha(1) antitrypsin and C1-INH (anti-inflammatory mediators) at T2 served to attenuate the acute phase/inflammatory response. The lower than normal resting concentrations of the acute phase proteins supports the notion that chronic aerobic exercise induces an anti-inflammatory state.

Influence of ultra-endurance exercise on immunoglobulin isotypes and subclasses.

BACKGROUND: Strenuous exercise is associated with tissue damage. This activates the innate immune system and local inflammation. Interaction between innate and adaptive immunity is essential for maintaining health, suggesting that the adaptive immune system may also be altered by exercise. OBJECTIVES: To determine exercise induced changes in the adaptive immune system by measuring the immunoglobulin isotype and subclass response to an ultra-marathon. METHODS: Venepuncture was performed on 11 experienced volunteers (six men, five women; mean (SD) age 43 (9.8) years) 24 hours before the projected finishing time and immediately after and 3, 24, and 72 hours after an ultra-marathon (90 km). Serum was stored at -80 degrees C. IgM, IgD, IgA, IgG, IgG1, 2, 3, and 4, and total IgE were measured. RESULTS: The following immunoglobulins were significantly (p< or =0.05) altered after the race: IgD, immediately (-51%) and 24 hours (-41%) after; IgM 24 hours after (-23%); total IgG immediately after (+12%). There were no reports of symptoms of upper respiratory tract infections after the ultra-marathon. CONCLUSIONS: In experienced ultra-endurance runners, alterations in immunoglobulin concentrations after a race suggest an enhanced immune response, including isotype switching, interactions with the innate immune system, and a secondary antibody response. These alterations may have a role in the maintenance of subject health after an ultra-marathon.

Octreotide lowers gastric mucosal blood flow in normal and portal hypertensive stomachs.

BACKGROUND: The vasoactive peptide octreotide has an established role in controlling variceal hemorrhage. The mechanism of action is believed to be a reduction in splanchnic blood flow. A decrease in splanchnic blood flow should be mirrored by a decrease in gastric mucosal blood flow (GMBF). Laser Doppler flowmetry (LDF) should detect changes in GMBF. METHODS: In seven normal volunteers and four patients with portal hypertension, 100 micro g of octreotide was administered as an intravenous bolus. Continuous LDF measurements were then made at a single point on the midantrum for at least 10 min and plotted against time for each subject. RESULTS: After a variable period of stabilization, GMBF decreased in all subjects except one. This was statistically significant in both the controls and the patients with portal hypertension. CONCLUSIONS: Octreotide decreases GMBF in normal and portal hypertensive stomachs. Laser Doppler is a useful and minimally invasive tool to assess the effect of drugs on GMBF.

A comparison of laser Doppler fluxmetry and transcutaneous oxygen pressure measurement in the dysvascular patient requiring amputation.

OBJECTIVE: To determine the predictive power of laser Doppler fluxmetry (LDF), both heated and unheated, as a preoperative investigation of wound healing potential in dysvascular patients requiring amputation, by comparison with transcutaneous oxygen pressure measurement (TcpO2) and the limb to chest TcpO2 index. METHODS: Thirty-five non-diabetic patients with peripheral vascular disease were investigated before amputation. Heated and unheated LDF and heated TcpO2 measurements were taken on the chest wall and at the routine above-knee, below-knee and mid-foot amputation levels. Wound healing potential was evaluated against a TcpO2 index value of 0.55 and on clinical outcome. RESULTS: A heated LDF value of 4.9 arbitrary units (au) was shown by receiver-operator characteristic curve to have the best predictive power, with an overall accuracy for preoperative prediction of wound healing of 91.4%, and a predictive value for wound failure of 89%. Based on the heated LDF of 4.9 au, review of 26 amputations performed shows the overall accuracy for preoperative prediction of wound healing of 92.3%, a predictive value for wound healing of 100%, and a predictive value for wound failure of 62.5%. CONCLUSION: A heated LDF value of 4.9 au appears to be a useful predictor of the potential of an amputation site to heal.