Background: Monitoring the daily change in resting heart rate variability can provide information regarding training adaptation and recovery status of the autonomic nervous system during training camps. However, it remains unclear whether postural stabilization is essential for valid and reliable ultra-short-term recordings in short-term overseas training camps.Design: Observational and longitudinal study.Purpose: This study aimed to investigate ultra-short-term heart rate variability recordings under stabilization or post-stabilization periods in four overseas training camps.Participant: Twenty-seven U-20 male national team futsal players voluntarily participated in (...) this study.Method: Resting HRV was evaluated for 10 min during the early morning of each training camp. The natural logarithm of the root mean square of successive normal-to-normal interval differences was used for comparisons. Time segments of HRV were divided into two periods with three measures within each: the first 30-s, the first 60-s, and the 5-min standard during stabilization; the first 30-s, the first 60-s, and the 5-min standard after stabilization.Result: The results demonstrated trivial to small ES, very large to nearly perfect ICC, and narrow range of SEM when all time segments of HRVUST were compared to the 1st_5 min and 2nd_5 min HRV. Furthermore, the magnitude of the correlation coefficients ranged from very high to nearly perfect for all the time segments. The HRVUST posted excellent agreement in all time segments with/without postural stabilization. Trivial to small levels of effect size in all time segments of LnRMSSDmean and LnRMSSDcv across overseas training camps was identified.Conclusion: The first 30 or 60-s LnRMSSD recordings can be used to evaluate daily cardiac-autonomic function during overseas training camps in futsal players. The process for stabilization seems to be unnecessary for measuring the morning resting LnRMSSD in overseas training camps among young adult futsal players. (shrink)

BackgroundThe rating of perceived exertion scales with respiratory and muscular illustrations are recognized as simple and practical methods to understand individual psychometric characteristics in breathing and muscle exertion during exercise. However, the implementation of respiratory and muscular RPE to quantify training load in futsal training camps has not been examined. This study investigates respiratory and muscular RPE relationships during domestic training camps and overseas training camps in an under 20 futsal national team.MethodsData collected from eleven field players were used for (...) comparison in this study. All players reported Borg CR10 RPE and 7-scales respiratory RPE and muscular RPE after training sessions and matches. Additionally, total distance covered and training impulse were used to quantify external and internal loads via the Polar Team Pro system. Paired-sample t-tests were used to compare the RPECR10, RPErespiration, RPEmuscle, TD, and TRIMP between DTC and OTC. Furthermore, linear regression was performed to determine the relationships among all RPE scales, TD, and TRIMP.ResultsThe RPECR10, TD, and TRIMP showed significant difference between DTC and OTC. Furthermore, linear regression analyses showed significant correlation between RPErespiration and RPEmuscle, RPECR10 and RPErespiration, and RPECR10 and RPEmuscle.ConclusionPictorial RPErespiration or RPEmuscle can be used as an alternative to quantify perceived measures of internal loads during DTC and OTC in futsal players. Interpretation of perceived measures of training load and cardiac-related responses in association with external training loads during short-term training camps would be useful in further understanding the demands of futsal players’ experience in these circumstances. (shrink)