Wylde, M.J., & Yong, L.C. (2015). Time-motion and heart-rate characteristics of adolescent female foil fencers. J. Hum. Sport Exerc., 9(Proc2), pp.S699-S706. Purpose: The aims of this study was to understand the time-motion and heart-rate characteristics of adolescent female foil fencing, explore the differences between the 5-touch and 15-touch bouts and compare these results with previous analysis of elite female foil fencers. Methods: Eight adolescent female foil fencers (age 14.3 ± 1.2 y, stature 157 ± 3.8 cm, body mass 45.9 ± 5.2 kg) were analysed at a youth fencing competition. Each fencer wore a heart-rate monitor throughout the competition and bouts were filmed so time-motion analysis could be carried out. Five movement classifications were used for the time-motion analysis, this were grouped into three categories based on movement intensity: Low, Moderate and High. Results: High-intensity movement accounted for 8.8 ± 4.4 % of total bout time with a mean duration of 0.8 ± 0.2 s. A higher percentage of low-intensity movement was recorded in the 15-touch bouts, with a higher percentage of high-intensity movement recorded in the 5-touch bouts. The mean duration of low-intensity movement was longer in the 15-touch bouts compared to the 5-touch bouts and a higher mean heart-rate was recorded in the 15-touch bouts compared to the 5-touch bouts. Conclusions: The results from this study suggest that adolescent female foil fencers perform a greater percentage of high-intensity movement in 5-touch bouts compared to 15-touch bouts. However, these fencers demonstrate a higher heart-rate in the 15-touch bouts. The practical application of this study is that adolescent female foil fencers must have a strong aerobic base to maintain a lower heart-rate in competition and ensure that fatigue does not become a limiting factor to performance.

Colocación de unidades de medición inercial en los deportes de raqueta: percepciones de los entrenadores sobre el uso de IMU durante el entrenamiento y la competencia.

The aim of this study was twofold, firstly to assess the reliability of the VX Sport Log GPS-based accelerometer, and secondly the validity of the same device compared to a Catapult Optieye S5 (considered a gold standard) recording at 100 Hz. Design & Methods: A total of 15 participants were recruited to take part in two separate trials of a Badminton specific endurance test. Reliability and validity assessments were conducted using coefficients of variation, intra-class correlation coefficient, Bland-Altman plots per axis (Vertical, Antero-posterior and Medio-lateral) and for vector magnitude (player load). Results: Reliability results demonstrate high levels of agreement between devices. Validity results also demonstrate high levels of agreement. However, there were issues with sample rate agreement between manufacturers of 0.25%. Conclusion: This study re-emphasises the need for sports utilising GPS-based accelerometers to conduct reliability and validity studies to ensure the consistency between data collection systems.

Adolescents are predisposed to poor sleep quality and experience shortened sleep durations due to biological and psychosocial factors. This trend is more pronounced amongst Asians. Sleep is acknowledged as a crucial component of recovery for athletes. However, a dearth of research exists on the sleep patterns of high-level adolescent-athletes. The purpose of this study was to examine the effects of different sport-training intensity on adolescent-athlete sleep patterns and investigate the effect of habitual weekday nocturnal sleep durations experienced by Asian adolescent-athletes. A secondary aim was to compare weekday-weekend sleep duration differences of Asian adolescent-athletes. 11 high-level adolescent bowlers (n = 6) and badminton players (14.8 ± 0.9 years, 52 ± 9 kg) were recruited from a sports school for this study and categorised as low (LIS) and high (HIS) –intensity sport athletes respectively. Training intensity was obtained using heart rate (HR) monitors during training. Validated objective sleep and subjective daytime sleepiness measures included wireless dry electroencephalography (EEG) sensors, wrist actigraphs, the Paediatric Daytime Sleepiness Scale (PDSS), and the Karolinska Sleepiness Scale (KSS). No differences in training durations were noted. HIS spent significantly more training time in HR zones of 61–70% (p < 0.01), 71–80% (p < 0.01) and 81–90% (p < 0.05) HRmax. No differences in sleep durations were noted on nights with EEG recordings. HIS athletes showed significantly more deep sleep (139 mins ± 20 vs. 93 ± 7; p < 0.05), less light sleep (158 mins ± 25 vs. 191 ± 7; p < 0.05) and wake time after sleep onset (1 min ± 0.4 vs. 4.4 ± 1.5; p < 0.05) as compared to LIS athletes. Actigraphically determined bedtimes and waketimes were significantly delayed on weekends for both groups of athletes (p < 0.05). Mean total sleep time was only significantly longer on weekends for HIS athletes (374 mins ± 20 vs. 458 ± 70; p < 0.05). HIS athletes presented with greater subjective daytime sleepiness scores (KSS) at 9 pm when compared to LIS (p < 0.05). A large effect size difference in PDSS scores was also observed amongst the HIS athletes (d = 1.25). These findings suggest that adolescent-athletes may have differing recovery-sleep requirements based on the nature of their sport.

Purpose: The purpose of this project was to utilise global-positioning system (GPS) technology to understand the physical demands of youth international field hockey. Methods: Sixteen male field hockey players (age 17.1 ± 0.6 y, stature 165 ± 11 cm, body mass 63.3 ± 6.6 kg, estimated VO2max, 52.6 ± 5.3 ml/kg/min) were investigated while competing in 6 matches at the 2011 Boy's Under-18 Asia Cup. Each player wore a GPS unit during competition to track his movement. These movements were classified as either low-speed activity (<4.17 m/s) or high-speed activity (>4.17 m/s). Positional differences were analysed using magnitude-based Cohen's effect size with modified qualitative descriptors. Results: Forwards covered the most distance per minute across total distance, low-speed activity and high-speed activity in the 6 youth international field hockey matches. For high-speed activity there was a "Large" difference between the Defenders and Midfielders and a "Very Large" difference between the Defenders and Forwards. Conclusion: In youth international field hockey, Forwards cover the greatest amount of distance and carry out the most high-speed activity, while Defenders perform the least amount of high-speed activity. This suggests that these playing positions are sufficiently different to warrant specialised positional training.