Factors affecting sports involvement in a school-based youth cohort: Implications for long-term athletic development

ABSTRACT

The aim of the present study was to determine the factors affecting sports involvement in a school-based adolescent population. The cross-sectional cohort study assessed anthropometry, physical capacities and motor competence in 501 boys (aged 10–16 y), from junior (10–12 y) and senior (13–16 y) cohorts. Sports participation data was collected from junior participants. Multivariate analysis of covariance revealed moderate maturity, anthropometry, physical capacity and motor competence differences between sports in the senior cohort (F = 2.616, p < 0.001, η² = .08), but not in the junior cohort. Furthermore, differences in physical fitness were revealed between playing levels (F = 2.616, p < 0.001, η² = .08), with a discriminant analysis correctly classifying 73% of participants using aerobic fitness and vertical jump measures. Representative level participants engaged in more structured training and commenced organised competition at a later age (F = 4.332, p < 0.001, η² = .21). This study’s findings are twofold: 1) physical and motor competence profiles differ more between sports with increasing age, and 2) participants at a higher level of competition report delayed engagement in their main sport. As a result, schools may be the ideal environment in which to provide children and adolescents with the opportunity to sample different sports.     

Effect of cadence selection on peak power and time of power production in elite BMX riders: A laboratory based study

ABSTRACT

The aims of this study were to analyse the optimal cadence for peak power production and time to peak power in bicycle motocross (BMX) riders. Six male elite BMX riders volunteered for the study. Each rider completed 3 maximal sprints at a cadence of 80, 100, 120 and 140 revs · min^?1 on a laboratory Schoberer Rad Messtechnik (SRM) cycle ergometer in isokinetic mode. The riders’ mean values for peak power and time of power production in all 3 tests were recorded. The BMX riders produced peak power (1105 ± 139 W) at 100 revs · min^?1 with lower peak power produced at 80 revs · min^?1 (1060 ± 69 W, (F(2,15) = 3.162; P = .266; η² = 0.960), 120 revs · min^?1 (1077 ± 141 W, (F(2,15) = 4.348; P = .203; η² = 0.970) and 140 revs · min^?1 (1046 ± 175 W, (F(2,15) = 12.350; P = 0.077; η² = 0.989). The shortest time to power production was attained at 120 revs · min^?1 in 2.5 ± 1.07 s. Whilst a cadence of 80 revs · min^?1 (3.5 ± 0.8 s, (F(2,15) = 2.667; P = .284; η² = 0.800) 100 revs · min^?1 (3.00 ± 1.13 s, (F(2,15) = 24.832; P = .039; η² = 0.974) and 140 revs · min^?1 (3.50 ± 0.88 s, (F(2,15) = 44.167; P = .006; η² = 0.967)) all recorded a longer time to peak power production. The results indicate that the optimal cadence for producing peak power output and reducing the time to peak power output are attained at comparatively low cadences for sprint cycling events. These findings could potentially inform strength and conditioning training to maximise dynamic force production and enable coaches to select optimal gear ratios.     

Heart rate and perceived muscle pain responses to a functional walking test in McArdle disease

Abstract

The aim of this study was to assess a 12-min self-paced walking test in patients with McArdle disease. Twenty patients (44.7 ±11 years; 11 female) performed the walking test where walking speed, distance walked, heart rate (HR) and perceived muscle pain (Borg CR10 scale) were measured. Median (interquartile range) distance walked was 890 m (470–935). From 1 to 6 min, median walking speed decreased (from 75.0 to 71.4 m?min^–1) while muscle pain and %HR reserve increased (from 0.3 to 3.0 and 37% to 48%, respectively). From 7 to 12 min, walking speed increased to 74.2 m?min^–1, muscle pain decreased to 1.6 and %HR reserve remained between 45% and 48%. To make relative comparisons, HR and muscle pain were divided by walking speed and expressed as ratios. These ratios rose significantly between 1 and 6 min (HR:walking speed P = .001 and pain:walking speed P < .001) and similarly decreased between 6 and 11 min (P = .002 and P = .001, respectively). Peak ratios of HR:walking speed and pain:walking speed were inversely correlated to distance walked: r_s (HR) = ?.82 (P < .0001) and r_s (pain) = ?.55 (P = .012). Largest peak ratios were found in patients who walked < 650 m. A 12-min walking test can be used to assess exercise capacity and detect the second wind in McArdle disease.     

Effects of autonomous motivational priming on motivation and affective responses towards high-intensity interval training

This study examined the effect of autonomous motivational priming on motivation, attitudes and intentions towards high-intensity interval training (HIT). Participants (N = 42) performed a graded exercise test to determine their peak aerobic power (W_PEAK). At a subsequent testing session, participants were randomised to complete either an autonomous or neutral motivational priming task followed by a 10 × 1 HIT exercise protocol, alternating 1-min bouts of hard (70% W_PEAK) and light (12.5% W_PEAK) exercises for 20 min. Participants primed with autonomous motivation reported greater enjoyment, P = .009, η_p² = .16, and perceived competence, P = .005, η_p² = .18, post-exercise compared to those in the neutral priming condition. Participants in the autonomous motivational priming condition also reported more positive attitudes, P = .014, η_p² = .14, towards HIT; however, there was no difference between the conditions for task motivation during HIT or intentions, P = .53, η_p² = .01, to engage in HIT. These findings highlight autonomous motivational priming as a method of enhancing affective and motivational experiences regarding HIT.     

Self-Controlled Practice Enhances Motor Learning in Introverts and Extroverts

Purpose: The purpose of the present study was to investigate the effects of self-controlled feedback on the learning of a sequential-timing motor task in introverts and extroverts. Method: Fifty-six university students were selected by the Eysenck Personality Questionnaire. They practiced a motor task consisting of pressing computer keyboard keys in a specific spatial and temporal pattern. The experiment consisted of practice, retention, and transfer phases. The participants were distributed into 4 groups, formed by the combination of personality trait (extraversion/introversion) and type of feedback frequency (self-controlled/yoked). Results: The results showed superior learning for the groups that practiced in a self-controlled schedule, in relation to groups who practiced in an externally controlled schedule, F(1, 52) = 4.13, p < .05, η² = .07, regardless of personality trait. Conclusion: We conclude that self-controlled practice enhances motor learning in introverts and extroverts.     

The Influence of Feedback on Competence,Motivation, Vitality,and Performance in a Throwing Task

Purpose: The purpose of this work is focused on the study of the effect that feedback has on competence valuation, perceived competence, autonomous motivation, vitality, and performance in a throwing task. Method: Thirty-five college students (26 men and 9 women), without previous experience in the task, participated in this study. The students were randomly assigned to three experimental conditions (positive, negative, and lack of feedback). Results: The results of this study point out that only those who received positive feedback before the handball throwing task, in contrast to those who received negative feedback or did not receive any feedback, showed increased levels of competence valuation (p < .05, Cliff’s delta effect size = ?.30), perceived competence (p < .001, Cliff’s delta effect size = ?.77), and autonomous motivation (p < .05, Cliff’s delta effect size = ?.48). This group also presented higher levels of perceived competence (p < .001, Cliff’s delta effect size = ?.84) and subjective vitality (p < .001, Cliff’s delta effect size = ?.80) than the group who received negative feedback after the throwing task. Those who received positive feedback also showed a higher throwing speed at the end of task than those who received negative feedback (p < 0.001, Cliff’s delta effect size = ?.71) or than those who did not receive any feedback (p < .05, Cliff’s delta effect size = ?.56). Conclusions: Competence valuation, perceived competence, autonomous motivation, subjective vitality, and throwing speed were favorably influenced by positive feedback. These results have important implications for the training style applied by coaches.     

Tensiomyographical responses to accelerometer loads in female collegiate basketball players

The purpose of the present study was to characterise the relationship between relative versus absolute internal and external loads in collegiate basketball players throughout the course of a season. Five Division I basketball players wore triaxial accelerometers throughout the 2015–2016 season and were tensiomyographically assessed weekly. One-way repeated-measure analysis of variance (RM ANOVA) with least-significant-difference (LSD) pairwise comparisons was used to determine which absolute weekly loads were different across the season. Cohen’s d was used to supplement the determination of meaningful relative load changes. Overall RM ANOVA models suggest absolute external load differences occurred (PlayerLoad? F = 17.63; IMA? F = 31.63). Two-way RM ANOVA models revealed main effect differences were revealed between muscle groups for Tc (F = 9.11) and Dm (F = 3.25). Meaningful relative load changes between weeks were observed for both external and internal. The present study observed that tensiomyography utilised as a tool to monitor internal load may be more suitable for detecting fatigue from relative external load changes versus absolute load attained. Limiting weekly training volume changes to ≤10% may maintain appropriate adaptation. Mediolateral plane IMA? and adductor longus muscle group may be pertinent metrics when monitoring female collegiate basketball athletes.     

The effect of westward travel across five time zones on sleep and subjective jet-lag ratings in athletes before and during the 2015’s World Rowing Junior Championships

This study examined sleep-wake habits and subjective jet-lag ratings of 55 German junior rowers (n = 30 male, 17.8 ± 0.5 years) before and during the World Rowing Junior Championships 2015 in Rio de Janeiro, Brazil. Athletes answered sleep logs every morning, and Liverpool John Moore’s University Jet-Lag Questionnaires each evening and morning. Following an 11-h westward flight with 5-h time shift, advanced bedtimes (?1 h, P < .001, η_p² = 0.68), reduced sleep onset latency (P = .002, η_p² = 0.53) and increased sleep duration (P < .001, η_p² = 0.60) were reported for the first two nights. Jet-lag symptoms peaked upon arrival but were still present after 6 days. Sleep quality improved (P < .001, η_p² = 0.31) as well as some scales of the Recovery-Stress Questionnaire for Athletes. Participation was successful as indicated by 11 of 13 top 3 placings. Overall, the initial desynchronisation did not indicate negative impacts on competition performance. As travel fatigue probably had a major effect on perceptual decrements, sleep during travel and time to recover upon arrival should be emphasised. Coaches and practitioners should consider higher sleep propensity in the early evening by scheduling training sessions and meetings until the late afternoon.     

Kicking Performance in Young U9 to U20 Soccer Players: Assessment of Velocity and Accuracy Simultaneously

Purpose: The purpose of this study was to compare the kicking performance of young soccer players in the U9 to U20 age groups. Method: Three hundred and sixty-six Brazilian players were evaluated on an official pitch using three-dimensional kinematics to measure (300 Hz) ball velocity (V_ball), foot velocity (V_foot), V_ball/V_foot ratio, last stride length, and distance between the support foot and the ball. Simultaneously, a two-dimensional procedure was also conducted to compute (60 Hz) the mean radial error, bivariate variable error, and accuracy. Possible age-related differences were assessed through one-way analysis of variance and magnitude-based inferences. Results: Ball velocity increased by 103% (p < .001, η² = .39) from the U11 age group (48.54 ± 8.31 km/hr) to the U20 age group (98.74 ± 16.35 km/hr). Foot velocity presented a 59% increase (p < .001, η² = .32) from the U11 age group (49.08 ± 5.16 km/hr) to U20 (78.24 ± 9.49 km/hr). This finding was due to improvement in the quality of foot–ball impact (V_ball/V_foot ratio) from U11 (0.99 ± 0.13 a.u.) to U20 (1.26 ± 0.11 a.u.; p < .001, η² = .25). Parameters such as mean radial error and accuracy appeared to be impaired during the growth spurt (U13–U15). Last stride length was correlated, low to moderately high, with V_ball in all age groups (r = .36–.79). Conclusions: In summary, we concluded that simple biomechanical parameters of kicking performance presented distinct development. These results suggest that different training strategies specific for each age group could be applied. We provide predictive equations to aid coaches in the long-term monitoring process to develop the kick in soccer or search for talented young players.     

Initial Validation of the Physical Education Marginalization and Isolation Survey (PE-MAIS)

Qualitative research conducted through occupational socialization theory has documented that physical educators feel marginalized and isolated in schools. We sought to propose and provide initial evidence of validity and reliability for the Physical Education Marginalization and Isolation Survey (PE-MAIS). Physical educators (n = 420) completed an online survey including isolation and marginalization, perceived mattering, and burnout. Data analyses began with exploratory factor analysis, which identified a stable 10-item, 2-factor structure. Confirmatory factor analysis was used to affirm the structure and examine convergent, discriminant, and divergent validity. The model fit was good, χ²(34) = 71.12, p < .001, NNFI = .91, CFI = .94, SRMR = .05, RMSEA = .07 (90% CI [.052, .093], p = .03), and the new measure correlated positively with burnout and negatively with perceived mattering. Invariance analysis indicated that elementary and secondary physical educators interpreted the constructs similarly, and there were no significant differences between the groups.     

New insight for activity intensity relativity,metabolic expenditure during object projection skill performance

This study examined the metabolic cost (METs) of performing object projection skills at three practice trial intervals (6, 12, and 30 seconds). Forty adults (female n = 20) aged 18–30 (M = 23.7 ± 2.9 years) completed three, nine-minute sessions of skill trials performed at 6, 12, and 30 second intervals. Participants performed kicking, throwing and striking trials in a blocked schedule with maximal effort. Average METs during each session were measured using a COSMED K4b2. A three (interval condition) X two (sex) ANOVA was conducted to examine differences in METs across interval conditions and by sex. Results indicated a main effect for interval condition (F(5,114) = 187.02, p < .001, η² = 0.76) with decreased interval times yielding significantly higher METs [30 sec = 3.45, 12 sec = 5.68, 6 sec = 8.21]. A main effect for sex (F(5, 114) = 35.39, p < .001, η² = 0.24) also was found with men demonstrating higher METs across all intervals. At a rate of only two trials/min, participants elicited moderate physical activity, with 12 and 6-second intervals exhibiting vigorous PA. Demonstrating MVPA during the performance of object projection skill performance has potential implications for PA interventions.     

Effects of Aerobic Exercise on Cognitive Performance Among Young Adults in a Higher Education Setting

Purpose: Acute benefits of aerobic exercise on executive functioning have been reported frequently under laboratory conditions. However, to date, a beneficial effect on long-term memory has been less well supported and no data are available regarding nonlaboratory conditions in young adults. The aim of the current study was to investigate acute effects of aerobic exercise on cognitive functioning in a university classroom setting. Method: Using a cross-over design, 51 participants performed a bout of moderately intense running (RUN) and read an article while seated (CON). Afterwards, they completed free-recall tests, followed by a Flanker task and an n-back task. Results: Participants in the RUN condition compared with those in the CON condition showed shorter reaction time on the inhibition task, F(1, 50) = 5.59, p = .022, η² = .101, and recalled more words in the immediate- and delayed-recall tests, F(1, 50) = 8.40, p = .006, η² = .144. Conclusion: The present findings suggest that a moderately intense bout of aerobic exercise benefits verbal short-term and long-term memory as well as inhibitory control among students in a classroom setting.     

The effects of weighted skates on ice-skating kinematics,kinetics and muscular activity

Sport-specific resistance training, through limb loading, can be a complimentary training method to traditional resistance training by loading the working muscles during all phases of a specific movement. The purpose of this study was to examine the acute effects of skating with an additional load on the skate, using a skate weight prototype, on kinematics, kinetics, and muscle activation during the acceleration phase while skating on a synthetic ice surface. 10 male hockey skaters accelerated from rest (standing erect with knees slightly bent) under four non-randomized load conditions: baseline 1 (no weight), light (0.9 kg per skate), heavy (1.8 kg per skate), and baseline 2 (no weight). Skating with additional weight caused athletes to skate slower (p < 0.001; η² = 0.551), and led to few changes in kinematics: hip sagittal range of motion (ROM) decreased (2.2°; p = 0.032; η² = 0.274), hip transverse ROM decreased (3.4°; p < 0.001; η² = 0.494), ankle sagittal ROM decreased (2.3°; p = 0.022; η² = 0.295), and knee sagittal ROM increased (7.8°; p < 0.001, η² = 0.761). Overall, weighted skates decreased skating velocity, but athletes maintained similar muscle activation profiles (magnitude and trends) with minor changes to their skating kinematics.     

Better Economy on Indoor Track Compared to Treadmill Running With 1% Inclination

ABSTRACT

Purpose: The purpose of this study was to investigate the differences in metabolic responses between the track and the treadmill (1% inclination) running. The latter is recommended for use in laboratory settings to mimic outdoor running. Method: Seventeen male endurance athletes (mean 25.8, s = 3.8 years) performed 4-min running bouts on an indoor track and the treadmill. Results: At all speeds (11, 13, and 15 km·h^?1) athletes showed better economy on the track running compared to the treadmill expressed as oxygen (7.9%, 5.2%, and 2.8%) and caloric (7.0%, 5.3%, and 2.6%) unit cost. Rating of perceived exertion was evaluated substantially higher at all speeds on the treadmill (F(1,16) = 31.45, p < .001, η²_p = .663) compared to running on the track. Participants presented lower heart rate (F(1,16) = 13.74, p = .002, η²_p = .462) on the track at the speed of 11 and 13 km·h^?1 compared to the treadmill, but not at 15 km·h^?1 (p = .021). Conclusions: We conclude that constant inclination (i.e.. 1%) during the treadmill test might not be suitable to reproduce comparable effort to running on the track; rather, there is an optimal treadmill inclination for different intensities to reproduce similar effort compared to the track running.     

The addition of whey protein to a carbohydrate–electrolyte drink does not influence post-exercise rehydration

The addition of whey protein to a carbohydrate–electrolyte drink has been shown to enhance post-exercise rehydration when a volume below that recommended for full fluid balance restoration is provided. We investigated if this held true when volumes sufficient to restore fluid balance were consumed and if differences might be explained by changes in plasma albumin content. Sixteen participants lost ~1.9% of their pre-exercise body mass by cycling in the heat and rehydrated with 150% of body mass lost with either a 60 g · L^?1 carbohydrate drink (CHO) or a 60 g · L^?1 carbohydrate, 20 g · L^?1 whey protein isolate drink (CHO-P). Urine and blood samples were collected pre-exercise, post-exercise, post-rehydration and every hour for 4 h post-rehydration. There was no difference between trials for total urine production (CHO 1057 ± 319 mL; CHO-P 970 ± 334 mL; P = 0.209), drink retention (CHO 51 ± 12%; CHO-P 55 ± 15%; P = 0.195) or net fluid balance (CHO ?393 ± 272 mL; CHO-P ?307 ± 331 mL; P = 0.284). Plasma albumin content relative to pre-exercise was increased from 2 to 4 h during CHO-P only. These results demonstrate that the addition of whey protein isolate to a carbohydrate–electrolyte drink neither enhances nor inhibits rehydration. Therefore, where post-exercise protein ingestion might benefit recovery, this can be consumed without effecting rehydration.     

Evaluation of the Psychometric Properties of the Parents’ Proxy MPAQ-C in Chinese Population

We examined psychometric properties of a Modified Physical Activity Questionnaire for Children (MPAQ-C). Thirty-two parents (Study 1), 40 students (6–9 years) and one of each student’s parents (Study 2), and 625 parents (Study 3) completed the MPAQ-C. The MPAQ-C (six items) measured children’s physical activity (PA) after school, and during evenings and weekends for 7 days. Test–retest reliability (Study 1) and convergent validity (Study 2) were measured. Factor validity of the MPAQ-C (Study 3) was examined using confirmatory factor analysis. A single-factor model of the MPAQ-C fit the data well (χ² (9) = 42.78, p < .001; comparative fit index[CFI] = .977; non-normed fit index [NNFI] = .962; root mean square error of approximation [RMSEA] = .079 [90% confidence interval {CI} = .057 to .11]), with good test–retest reliability, composite reliability (.80) and convergent validity. The factor loadings of MPAQ-C were invariant across fathers/mothers (Δχ² (6) = 3.44, p > .05). The MPAQ-C is a suitable parent proxy for measuring young Chinese children’s PA.