Physical education & sports science expert book series
To design and write a book on chapters pertaining to a variety of sports for children and adolescents to enjoy the process of being physically active.
Background
The American College of Sports Medicine (ACSM, 2015) states that a sedentary lifestyle is one of the major risk factors for obesity and cardiovascular disease. Therefore, physical activity is essential and it starts from a young age. Children have to be exposed to a variety of sports, games and activities. ACSM recommends 60 minutes daily of physical activity for children and adolescents. If children are unable to accumulate 60 minutes in day, they can begin with a lower duration and subsequently increasing the duration slowly as they progress over the months. The following chapters are written and designed by our experts in their special area of work and sport that will provide a deeper understanding and greater insight to sports and exercise in general, from a recreational perspective to a competitive level. Each chapter will reveal the history, background, basic rules of the sport, and how to implement modified games during PE lessons. The chapters also provide PE educators, coaches and parents with necessary tools to teach the sport.
Comparing the effects of plyometric and isometric strength training on dynamic and isometric force-time characteristics
The purpose of the study was to compare the change in dynamic and isometric force-time characteristics after plyometric (PLYO) or isometric strength training (ISO). Twenty-two endurance runners (age = 37 ± 6 years,stature = 1.71 ± 0.05 m, body mass = 62.7 ± 8.6 kg, weekly mileage = 47.3 ± 10.8 km) performed a countermovement jump (CMJ) and isometric mid-thigh pull (IMTP) test during pre- and post-tests. They were then randomly assigned to either PLYO or ISO group and completed 12 sessions of intervention over six weeks. The PLYO included drop jump, single leg bounding and split jump, and the ISO included IMTP and isometric ankle plantar flexion. Significant and large time x group interactions were observed for CMJ countermovement depth (P = 0.037, ƞ²p = 0.21) and IMTP and relative peak force (PF) (P = 0.030, ƞ²p = 0.22). Significant and large main effects for time were observed in CMJ height, peak power, propulsive phase duration, countermovement depth, reactive strength index modified, IMTP PF and relative PF (P < 0.05, 0.20 ≤ ƞ²p ≤ 0.65). Effect for time showed small improvement in CMJ height for both PLYO (P < 0.001, d = 0.48) and ISO (P = 0.009, d = 0.47), small improvement in CMJ PP in PLYO (P = 0.020, d = 0.21), large increase in countermovement depth (P = 0.004, d = 1.02) and IMTP relative PF (P < 0.001, d = 0.87), and moderate increase in propulsive phase duration (P = 0.038, d = 0.65) and IMTP PF (P < 0.001, d = 0.55) in ISO. There were large differences between groups for percentage change in countermovement depth (P = 0.003, d = 0.96) and IMTP relative PF (P = 0.047, d = 0.90). In conclusion, both PLYO and ISO improved CMJ jump height via different mechanisms, while only ISO resulted in improved IMTP PF and relative PF.
Effects of soy milk ingestion on anaerobic performance and physiological measures
The purpose of this study was to investigate the effects of soy protein supplementation to improve performance and recovery during repeated running anaerobic sprint test (RAST). Ten males (age: 23.2 ± 1.23 yrs) performed two RAST with a soy milk intervention (SOY; 500 mL soy milk + 4 g stevia sweetener) and a placebo control (CON; 500 mL water + 4 g stevia sweetener) over 7 days. The RAST consisted of six 35-m sprints with a 10-sec recovery between each sprint. The total effort time (sec) was not significant between SOY (32.77 ± 1.23) and CON (33.28 ± 1.71) (P = 0.179). Fatigue index in SOY (31.64 ± 5.20) was significantly lower than CON (37.30 ± 5.70) (P = 0.023). Mean power (Watts) (Soy: 499.27 ± 62.72, Con: 486.39 ± 86.13) (P = 0.410), relative power (Watts) (Soy: 9.34 ± 1.02, Con: 9.55 ± 1.51) (P = 0.461), peak blood lactate (mmol·L-1) (Soy: 9.75 ± 1.61, Con: 10.24 ± 1.90) (P = 0.488), and peak blood glucose (mmol·L-1) (Soy: 23.94 ± 3.90, Con: 25.09 ± 4.61) (P = 0.497) between trials were not significant. Peak blood lactate (r = -0.654) and glucose (r = -0.662) concentrations were inversely associated with mean power in the SOY trial. The results indicate that the soy milk intervention in RAST significantly lowered the fatigue index and, therefore, may be used to enhance sports performance involving anaerobic activities.
Effects of isometric strength and plyometric training on running performance: A randomized controlled study
Purpose: The aim of the study was to compare the effects of isometric strength (IST) and plyometric training (PT) on endurance running performance. Methods: Twenty-six endurance runners (18 males and 8 females; age 36 ± 6 years, stature 1.69 ± 0.05 m body mass 61.6 ± 8.0 kg, VO2max 50.4 ± 5.8 ml·kg−1·min−1) completed the countermovement jump (CMJ), isometric mid-thigh pull (IMTP), 2.4 km run time trial (2.4kmTT), running economy test (RE) and a graded exercise test measures at baseline. They were then randomly assigned to three groups, the control (CON), PT or IST group, and completed the circuit, plyometric or isometric training, respectively, twice a week for 6 weeks, while still continuing to perform their planned running training. They then completed the same set of measures performed at baseline post-intervention. Results: Significant time x group interactions and time main effect were observed for 2.4kmTT (P = .002, ƞ2p = .45 and P < .001, ƞ2 =0.72), maximal aerobic speed (MAS) (P = .006, ƞ2p = .39), CMJ height (P < .001, ƞ2p = .55) and IMTP relative peak force (P = .001, ƞ2p = .50) in favor of PT and IST. Significant main effect for time was observed for 2.4kmTT (P < .001, ƞ2p = .72), RE (P = .048, ƞ2p = .17), VO2max (P = .047, ƞ2p = .18), MAS (P < .001, ƞ2p = .63), CMJ height (P < .001, ƞ2p = .51) and IMTP relative peak force (P < .001, ƞ2p = .58). Conclusion: In conclusion, both PT and IST were similarly effective at enhancing running endurance performance. However, IST resulted in greater improvement to RE.
Sprint kayaking performance enhancement by isometric strength training inclusion: A randomized controlled trial
Performing isometric strength training (IST) can enhance various sports performance. This study compared the effects of including IST on sprint kayaking performance as compared to traditional strength training. Twenty sprint kayaking athletes (age 22 ± 4 year, stature 1.71 ± 0.09 m, body mass 72.0 ± 11.4 kg) performed a 200-m kayak ergometer time trial (200mTT), isometric squat (IsoSqT), isometric bench press (IsoPress) and isometric prone bench pull (IsoPull) during the pre- and post-tests. Athletes were randomly assigned to either traditional strength training (TRAD) or IST group. Both groups performed a similar strength training program twice a week for six weeks. However, half the volume for squat, bench press and prone bench pull were replaced by IsoSqT, IsoPress and IsoPull, respectively, for the IST group. IsoSqT was performed at 90° knee angle, while IsoPress and IsoPull were performed at 90° and 120° elbow angles, respectively. Each isometric contraction was performed with maximum intensity and sustained for three seconds. A significant main time effect was observed for 200mTT (p < 0.001, ƞ2p = 0.68) and all isometric strength measures (p = 0.001–0.032, ƞ2p = 0.24–0.76) except rate of force development at 0–90 ms (RFD90) obtained from IsoSqT120 and IsoPress90. A group main effect was observed in RFD90 obtained from IsoSqT120 and IsoPull120 (p = 0.003–0.004, ƞ2p = 0.37–0.39). Time x Group interaction was observed for 200mTT (p = 0.027, ƞ2p = 0.68), peak force obtained from IsoSqT90, IsoPress90, and IsoPull120 (p = 0.004–0.006, ƞ2p = 0.36–0.38) and RFD90 obtained from IsoSqT120 and IsoPull120 (p = 0.012–0.015, ƞ2p = 0.28–0.30). Inclusion of IST resulted in greater improvement for sprint kayaking and strength performances then TRAD alone.
Physical activity among adults residing in 11 countries during the COVID-19 pandemic lockdown
During the novel coronavirus (COVID-19) pandemic, physical activity (PA) behaviors were altered worldwide due to public health measures such as “lockdown.” This study described PA among adults residing in 11 countries during COVID-19 lockdown and examined factors associated with PA engagement. We conducted a cross-sectional anonymous survey among adults (≥18 years old) in 11 countries (Brazil, Bulgaria, China, India, Ireland, Malaysia, North Macedonia, Singapore, Spain, Turkey, United States). Of 11,775 participants, 63.7% were female and 52.8% were 18–34 years old. More than 40% of participants were insufficiently active (43.9%) and reported a decrease in their PA during lockdown (44.8%). Statistically significant differences were observed in (1) proportions of participants being insufficiently active, (2) level of PA, and (3) decrease in PA across the 11 countries. More stringent governmental policy responses were associated with greater likelihood of being insufficiently active during lockdown (adjusted odds ratio = 1.22, 95% confidence interval = 1.03, 1.45). Higher depression or anxiety scores were associated with greater likelihood of decreased level of PA during lockdown.We found substantial reductions in PA levels during COVID-19 lockdown across countries. Country-specific PA promotion interventions are needed during this and similar global emergencies.
Arm-pull thrust in human swimming and the effect of post-activation potentiation
The aim of this study was to analyse the front-crawl arm-pull kinetics and kinematics, comparing it before and after post-activation potentiation (PAP), and the associations between variables describing of the arm-pull kinetics. Twelve male competitive swimmers were randomly assigned to perform two different warm-ups in a crossover manner: (i) non-PAP (control condition); and (ii) PAP (experimental condition). PAP consisted of 2 × 5 arm-pulls with resistance bands by both upper-limbs. Eight minutes later, participants underwent a 25 m all-out trial in front-crawl arm-pull. Kinetics (i.e., peak thrust, mean thrust and thrust-time integral) and kinematics (i.e., speed and speed fluctuation) were collected by an in-house customised system composed of differential pressure sensors, speedo-meter and underwater camera. There was a significant and large improvement of the arm-pull kinetics after completing the warm-up with PAP sets (0.010 < P < 0.054, 0.50 < d < 0.74). There were non-significant and small effects of PAP on speed (P = 0.307, d = 0.18) and speed fluctuation (P = 0.498, d = 0.04). Correlation coefficients among kinetic variables were significant with large associations (0.51 < R < 0.90, 0.001 < P < 0.088). In conclusion, warm-ups including PAP conditioning sets elicit a large improvement in the thrust, but with small improvement in performance. Variables used to characterise thrust are strongly correlated and hence can be used interchangeably.
A normalized rate of perceived exertion at ventilatory breakpoint for different exercise modalities and production of exercise intensity with self-regulation for Singapore children
BACKGROUND: The purpose of this study was to identify a normalized RPE response at ventilatory breakpoint (Vpt) for male adolescents 13-17 years old, and whether these adolescents could self-regulate at target RPEs of 4 and 6.
METHODS: Twenty healthy males participated in the study, with 10 males in each of the cycling and walking/running groups. Participants performed orientation and V̇O2peak trials before performing a perceptual estimation exercise trial to obtain RPE Vpt, and two production trials to assess self-regulation ability.
RESULTS: Vpt corresponded to 67.7% V̇O2peak for the cycling group and 70.4% V̇O2peak for the walking/running group. There were no group differences on RPE-Overall Vpt (cycling: 4.6; walking/running: 4.4), RPE-Legs Vpt (cycling: 5.4; walking/running: 4.6), and RPE-Chest Vpt (cycling: 4.0; walking/running: 4.8). A normalized RPE-Overall Vpt response was identified at five. V̇O2 did not differ between the estimation and production trials at targets RPE of 4 (1.59 vs. 1.57 L·min-1) and 6 (1.87 vs. 1.79 L·min-1). Similarly, heart rate (HR) did not differ between estimation and production trials at targets RPE 4 (152.4 vs. 151.1 beats·min-1) and 6 (167.1 vs. 162.4 beats·min-1). Both V̇O2 and HR were significantly higher at RPE 6 compared to RPE 4. Responses were not affected by exercise mode or production sequence.
CONCLUSIONS: This study demonstrated that undifferentiated and differentiated RPE Vpt were similar between cycling and walking/running participants. Male adolescents between 13- and 17-year-olds were able to use the OMNI scale to self-regulate exercise intensities that would be useful in field settings.
Using Brain-Breaks® as a technology tool to increase attitude towards physical activity among students in Singapore
The purpose of this study was to investigate the effects of classroom-based Brain Breaks® Physical Activity Solution in Southeast Asia Singaporean primary school students and their attitude towards physical activity (PA) over a ten-week intervention. A total of 113 participants (8-11 years old) were randomly assigned to either an experimental (EG) or a control group (CG), with six classes to each group; the Brain Breaks® group (EG: six classes) and the Control group (CG: six classes). All EG members participated in a Brain Breaks® video intervention (three-five min) during academic classes and the CG continued their lessons as per normal. The student's attitudes towards PA in both research conditions were evaluated using the self-reported Attitudes toward Physical Activity Scale (APAS), applied before and after intervention. The effects of the intervention on APAS scores were analysed using a mixed model analysis of variance with Time as within-subject and Group as between-subject factors. The analysis revealed evidence in support of the positive effect of classroom video interventions such as Brain Breaks® on student's attitudes toward benefits, importance, learning, self-efficacy, fun, fitness, and trying to do their personal best in PA. The Brain Breaks® intervention provided a positive significant impact on students in Singapore. This study also revealed that interactive technology tools implemented into the school curriculum benefit students in terms of health and education.
Brain Breaks® physical activity solutions in the classroom and on attitudes toward physical activity: A randomized controlled trial among primary students from eight countries
Classroom-based physical activity (PA) interventions have received considerable attention due to improvements seen in academic achievement, classroom behaviors, and attitude toward PA. The purpose of this study was to evaluate the effectiveness of the Brain Breaks® Physical Activity Solutions in changing children’s attitudes toward PA. Students (N = 3036) aged 8–11 years from schools in Croatia, Lithuania, Macedonia, Poland, Romania, Serbia, South Africa, and Turkey were randomly assigned to either a control or an experimental group. The experimental group received Brain Breaks® videos during classroom sessions throughout the four months of intervention. Student attitudes toward PA were measured using the Attitudes toward Physical Activity Scale (APAS) before and after the intervention. Repeated measures ANOVA indicated a time interaction effect for all APAS variables except fitness. Time-by-group interaction effects with different effect sizes were found for most APAS variables, with the greatest gain effect noted in the experimental group for self-efficacy, followed by learning from the videos concerning PA benefits, exercise importance, and enjoyment from engaging in PA. This study provides evidence supporting Brain Breaks® in terms of learning experience, attitudes towards PA, and personal motivation. Using exercise videos is recommended as an interactive, technology-based PA solution that can be easily integrated into the school setting.