title: Monitoring weekly heart rate variability in futsal players during the preseason: the importance of maintaining high vagal activity.
abstract: This study aimed to compare the weekly natural log of the root-mean-square difference of successive normal inter-beat (RR) intervals (ln RMSSDWeekly) and its coefficient of variation (ln RMSSDCV) in response to 5 weeks of preseason training in professional male futsal players. A secondary aim was to assess the relationship between ln RMSSDWeeklyand ln RMSSDCV. The ln RMSSD is a measure of cardiac-vagal activity, and ln RMSSDCVrepresents the perturbations of cardiac autonomic homeostasis, which may be useful for assessing how athletes are coping with training. Ten futsal players had their resting ln RMSSD recorded prior to the first daily training session on four out of approximately five regular training days · week-1. Session rating of perceived exertion (sRPE) was quantified for all training sessions. Despite weekly sRPE varying between 3455 ± 300 and 5243 ± 463 arbitrary units (a.u.), the group changes in ln RMSSDWeeklywere rated as unclear (using magnitude-based inference), although large inter-individual variability in ln RMSSD responses was observed. The ln RMSSDCVin weeks 4 and 5 were likely lower than the previous weeks. A large and significant negative correlation (r = -0.53; CI 90%: -0.36; -0.67) was found between ln RMSSD and ln RMSSDCV. Therefore, monitoring individual ln RMSSD responses is suggested since large inter-individual variations may exist in response to futsal training. In addition, higher values of ln RMSSD are associated with lower oscillations of cardiac autonomic activity.
authors.affiliation: a NAR - Nucleus of High Performance in Sport , São Paulo , Brazil.|b Department of Physical Education , State University of Londrina , Londrina , Brazil.
authors.forename: Fabio Y
authors.initials: FY
authors.lastname: Nakamura
authors.affiliation: a NAR - Nucleus of High Performance in Sport , São Paulo , Brazil.
authors.forename: Lucas A
authors.initials: LA
authors.lastname: Pereira
authors.affiliation: c Department of Futsal , Sport Club Corinthians Paulista , São Paulo , Brazil.
authors.forename: Felipe N
authors.initials: FN
authors.lastname: Rabelo
authors.affiliation: d Exercise Physiology Laboratory, Department of Kinesiology , University of Alabama , Tuscaloosa , AL , USA.
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Flatt
authors.affiliation: d Exercise Physiology Laboratory, Department of Kinesiology , University of Alabama , Tuscaloosa , AL , USA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Esco
authors.affiliation: e Department of Medicine and Aging Sciences, Behavioral Imaging and Neural Dynamics Center , University "G. d'Annuzio" of Chieti-Pescara , Chieti , Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Bertollo
authors.affiliation: a NAR - Nucleus of High Performance in Sport , São Paulo , Brazil.
authors.forename: Irineu
authors.initials: I
authors.lastname: Loturco
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D002319:Cardiovascular System; D006339:Heart Rate; D006801:Humans; D008297:Male; D010465:Perception; D064797:Physical Conditioning, Human / Q000502:physiology*; D005082:Physical Exertion; D012146:Rest; D012621:Seasons; D012916:Soccer / Q000502:physiology*; D014630:Vagus Nerve; D055815:Young Adult
keywords: Cardiac autonomic activity; court sports; indoor soccer; overloading; overreaching