Michael Chia

Inadequate hydration before, during and after exercise puts the safety and well-being of Singaporean youths at risk especially when sports training and Physical Education (PE) lessons are conducted outdoors, under the hot and humid weather conditions of Singapore. The study examined the exercise knowledge of youth athletes in Singapore schools: 586 youth athletes from four primary schools, four secondary schools and one junior college. All participants completed a validated exercise hydration knowledge quiz that was developed based upon the consensus statements and position stands of two international sports associations. An average knowledge score of 44.7±14.0% (range 0–87.1%) was obtained, which was significantly below the minimum competence score of 80%. Post-exercise hydration knowledge was lacking when compared to pre-exercise and during-exercise hydration knowledge. Overall, exercise hydration knowledge gaps were identified, in particular for post-exercise hydration; still the majority of participants from all schooling levels did not attain the competence score of at least 80%. Coach education and PE training programmes should specifically target and ameliorate these knowledge deficiencies to empower youth athletes to take personal responsibility for their safe participation and training in sports.

The purpose of the study was to examine the reliability and validity of school-based pedometer step counts in Singaporean children. Participants were 10 boys and 10 girls aged 10-11 years old. School-based physical activity was monitored over a five-hour period using an electronic pedometer (PCB 147PDO) and a tri-axial accelerometer (RT3), fastened securely at the waist. Test-retest measurements of physical activity revealed no significant differences in step count (21.86.1 vs. 22.16.3 steps/min, p>0.05) and vector magnitude (580.470.9 vs. 581.189.4 vm!mln, p>o.o51. The girls' physical activity measurements were 77.5 % and 87.4 % that of boys'for pedometer and accelerometer readings. Typical error (TE) expressed as a coefficient of variation (CV) for repeated measurements were 9.6% for pedometry compared to 4% for accelerometry. Intra-class correlations (ICC) were 0.90 for step count and 0.92 for vector magnitude, while Bland and Altman plots showed a similar spread of activity readings for the pedometer and accelerometer. Significant correlations were established between accelerometer readings and pedometer readings (r>0.75, p<0.05). Data from the study showed that the electronic pedometer was a reliable and valid motion sensor for assessing the school-based physical activity of Singaporean children, using a variety of reliability indicators. With the reliability and validity of pedometers established, future research should focus on the efficacy of intervention programs to curtail sedentary behaviours and heighten the attractiveness of active behaviours in the context of school.

The purpose of the study was to examine the isokinetic leg extension torque of adult participants using allometric scaling to account for differences in body mass. 10 men (23.1y, 1.72m & 64.5kg) and nine women (20.7y, 1.62m & 52.1kg) participated in the study. Peak isokinetic leg extension torque at 1.02, 3.12 and 5.20 rad•s-1 were determined using a Cybex 6000 isokinetic dynamometer. Torque at 1.04 rad•s-1 was significantly higher than torque at 3.12 rad•s-1 and 5.20 rad•s-1 in men and women. Torque in newton.metre in men were 162.5, 167.3 and 151.3% but were reduced to 130.2, 126.2 and 121.8% that of women when the data were allometrically scaled to body massb=0.89, 1.13 & 0.97. Common identified b exponents between torque and body mass included b=1.0 within the 95% confidence intervals, as predicted by geometric similarity theory.

The purpose of the study was to examine ifthe Wingate Anaerobic Test (WAnT) is a reliable anaerobic test for boys with intellectual di sability (I D). Sixteen adolescent boys (aged 15.5±1.0yr ) with ID (lQ range 30-50) and with appropriate informed consents performed a 30-s Wingate Anaerobic Test on a cycle ergometer on two separate days. The results indicated that even though adolescent boys with ID had lower PP and MP values than their peers without ID, and were more variable in their performances, given appropriate habituation and practice prior to testing, adolescent males with ID were able to perform the WAnT with significant ' levels (P<0.05) of reliability, agreement and variation.

Both aerobic and anaerobic exercise contributes to oxidative stress by generation of free radicals. The human body is well equipped with both enzymatic and non-enzymatic antioxidant defence system. Soccer predominantly involves aerobic exercise with repeated bouts of anaerobic activities. The response of the different antioxidants to exercise might be sports-specific and hence the total antioxidant capacity (TAC) provides a better appraisal of the different antioxidant mechanisms of the body. TAC is the sum of the activities of antioxidants present in the material studied. The objective of the present study was to assess the urinary TAC (uTAC) in professional soccer players in different phases of the playing season and to compare the uTAC between professional, amateur and recreational soccer players. 21 professional, 20 amateur and 18 recreational players participated in the study. Results showed that the uTAC in the professional soccer players during pre-season (phase -1), early in-season (phase -2) and during the start of the end-season (phase - 3) was (mean ± SD) 3.13 ± 0.09, 2.73 ± 0.37 and 2.99 ± 0.41 mmol·L-1 respectively. The uTAC of the amateur and the recreational players during the start of end-season phase was 2.89 ± 0.44 and 1.77 ± 0.66 mmol·L-1 respectively. Repeated Measures ANOVA revealed significant difference (p <0.05) in the uTAC between phase-1 and phase-2 while no significant difference was detected between the other phases in the professional soccer players. One-way ANOVA revealed significant difference (p < 0.05) between the uTAC of the recreational players and the amateur and professional players while there was no significant difference (p > 0.05) in the uTAC between amateur and professional players. In conclusion, the present study found that the uTAC in professional soccer players changes through the course of the competitive season especially at the start of the early in-season period. Further, this study also found that the uTAC in both amateur and professional was higher than in the recreational soccer players. Further research is required to determine the response of the specific antioxidants to soccer training and performance during the different phases of the season and at different levels of participation.

Hurried and highly scheduled lifestyles among children are common, especially among developed countries in East Asia such as in Singapore. Research data suggest that young people do not meet daily activity guidelines that promote physical health. There is a cogent need to reconsider, resurrect and reposition play in young people such that children can internalise the merits of play and caregivers can recognise that play confers social-emotional outcomes that are valued by those who invest in education. Data emanating from Singapore suggest very promising social-emotional learning outcomes following a 10-week intervention programme conducted during school curriculum hours.

The study investigated the muscle power of the lower limbs in a group of 13 and 14 year old boys and girls. Participants were 45 boys (stature: 1.69±0.05 m; body mass: 57.9±11.8 kg; lower limb muscle mass: 16.4±2.5 kg) and 36 girls (stature: 1.59±0.06 m; body mass: 57.7±7.6 kg; lower limb muscle mass: 12.5±1.2 kg). Lower limb muscle mass (LLMM) was determined using a dual energy X-ray absorptiometric (DEXA) procedure. Participants completed a 30 s Wingate Anaerobic Test (WAnT) where peak power (PP) and mean power (MP) were expressed in relation to LLMM using ratio-scaling and log-linear adjustment procedures. Boys and girls had similar body mass-accounted PP (37.7 vs. 37.6 W/kg, P>0.05) and MP (28.0 vs.33.7 W/kg, P>0.05) when ratio-scaled to LLMM, or when the same data were log-linearly adjusted for PP (495W vs. 488W, P>0.05) and for MP (423W vs. 422W, P>0.05) in relation to LLMM. However, common b exponents that defined the allometric relationship between PP and MP, and LLMM in both boys and girls were 1.26 (SE 0.15), and 1.21 (SE 0.15), respectively. These were markedly different from the b exponent of 1.0 used in the ratio standard, or the 0.67 value predicted from geometric similarity theory. Despite a similar interpretation of data (i.e. no sex difference in lower limb muscle power in boys and girls) using either allometric modeling or ratio-scaling, expressed in relation to LLMM, allometric modeling of sample-specific exercise data is recommended to produce an appropriate size-independent variable, to allow appropriate comparisons in performance between boys and girls. Data in the study showed no sex difference in WAnT power expressed in relation to LLMM in adolescent boys and girls.

Body composition is an important aspect of soccer fitness. There is a dearth of longitudinal data on the intraseasonal variation in the body composition parameters of youth professional soccer players especially of Asian origin. This study assessed the body composition profile of the Asian youth professional soccer players (n=20; Mean ± SD, age 17.5 ± 0.3 years, stature 1.73 ± 0.04 m, body mass 67.2 ± 7.5 kg) through the entire season. Body mass, percentage body fat (% BF), lean body mass (LBM) and bone mineral density (BMD) of outfield youth professional soccer players was determined using dual-energy x-ray absorptiometry (DXA) during the pre-season, early in-season and end mid-season respectively. Results showed that the Asian youth professional soccer players had similar anthropometric characteristics compared to Asian adult elite players but were shorter and lighter than European youth players. There was a significant decrease (p < 0.05) in the % BF and a significant increase (p < 0.05) in LBM during the pre-season period. However, negative adaptations during the competition phase indicated that training and competition load was insufficient to improve or maintain the adaptations in the % BF and LBM. The whole body BMD significantly increased through the soccer season. Area-specific BMD of the pelvis and the lower limbs showed positive osteogenic adaptations during the soccer season. Our results showed that the body composition parameters of Asian youth professional soccer players change through the soccer season. Such data can expand the bases of comparison between different soccer playing populations and add to the prospects of research on soccer performance. Further studies on the effect of body composition parameters on different aspects of soccer performance are desirable.

Maximal oxygen uptake, V02 peak, among athletes is an important foundation for all training programmes to enhance competition performance. In Singapore, the \ro2 peak of athletes is apparently not widely known. There is also controversy in the modelling or scaling of maximal oxygen uptake for differences in body size-the use of ratio-scaling remains common but allometric scaling is gaining acceptance as the method of choice. Materials and Methods: One hundred fifty-eight male (age, 21.7± 4.9 years; body mass, 64.8± 8.6 kg) and 28 female (age, 21.9 ± 7.0 years; body mass, 53.0 ± 7.0 kg) athletes completed a maximal treadmill run to volitional exhaustion, to determineyo2 peak.~: \ro2 peak in L/min of female athletes was 67.8% that of male athletes (2.53 ± 0.29 vs. 3.73 ± 0.53 L/min), and \ro2 peak in mL/kg BMt.0/min of female athletes was 83.4% of male athletes (48.4 ± 7.2 vs. 58.0 ± 6.9 mL/kg BMt.0/min). Ratioscaling of \ro2 peak did not create a size-free variable and was unsuitable as a scaling method. Instead, \rQ2 peak, that was independent of the effect of body mass in male and female athletes, was best described using2 separate and allometrically-derived sex-specific regression equations; these were \rQ2 peak = 2.23 BM0.670 or male athletes and \ro2 peak = 2.23 BM0.24 for female athletes.