title: Heart rate variability in elite sprinters: effects of gender and body position.
abstract: To describe the heart rate variability (HRV) of high-level sprinters in both the supine and standing positions, the HRV of 7 male (24 ± 6 years; 80 ± 8 kg and 182 ± 7 cm) and 11 female (27 ± 5 years; 61 ± 4 kg; 167 ± 5 cm) high-level Brazilian sprinters was measured in the standing and supine body positions in both the time and frequency domains. The heart rate (HR) and the time (SDNN, RMSSD) and frequency (LF; HF and LF:HF) domains of the HRV were assessed. Natural log-transformations (ln) of all HRV indices were log-transformed prior to analysis to reduce bias arising from non-uniformity of error. The Cohen's effect size and magnitude-based inference (MBI) were obtained for comparisons. The results suggest higher cardiac autonomic stress in the standing position than in the supine for both genders. With the exception of the lnSDNN that showed possibly MBI in female athletes, all other HRV indices presented a likely or almost certainly MBI. Male athletes demonstrated a higher lnSDNN in the supine body position (very likely MBI) and a higher HR in the standing position (very likely MBI) than females. In conclusion, elite sprinters (independent of the gender) present lower HRV in the standing position than in the supine position, but males present a more notable change in cardiac autonomic stress than female athletes.
authors.affiliation: Sport Science, NAR - Nucleus of High Performance in Sport, São Paulo, SP, Brazil.
authors.forename: Cesar
authors.initials: C
authors.lastname: Abad
authors.affiliation: Sport Science, NAR - Nucleus of High Performance in Sport, São Paulo, SP, Brazil.
authors.forename: Ronaldo
authors.initials: R
authors.lastname: Kobal
authors.affiliation: Sport Science, NAR - Nucleus of High Performance in Sport, São Paulo, SP, Brazil.
authors.forename: Katia
authors.initials: K
authors.lastname: Kitamura
authors.affiliation: Sports Performance, School of Physical Education and Sport, University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Saulo
authors.initials: S
authors.lastname: Gil
authors.affiliation: Sport Science, NAR - Nucleus of High Performance in Sport, São Paulo, SP, Brazil.
authors.forename: Lucas
authors.initials: L
authors.lastname: Pereira
authors.affiliation: Sport Science, NAR - Nucleus of High Performance in Sport, São Paulo, SP, Brazil.
authors.forename: Irineu
authors.initials: I
authors.lastname: Loturco
authors.affiliation: Physical Education, State University of Londrina, São Paulo, SP, Brazil.
authors.forename: Fábio
authors.initials: F
authors.lastname: Nakamura
mesh_terms: D000293:Adolescent; D000328:Adult; D056352:Athletes; D001341:Autonomic Nervous System / Q000502:physiology*; D005260:Female; D006321:Heart / Q000294:innervation*; D006339:Heart Rate; D006801:Humans; D008297:Male; D011187:Posture; D012420:Running; D012737:Sex Factors; D016683:Supine Position; D013997:Time Factors; D055815:Young Adult
keywords: autonomic nervous system; body position; body posture; cardiac autonomic regulation; heart rate variability; spectral analysis; time and frequency domains