title: Postexercise autonomic function after repeated-sprints training.
abstract: OBJECTIVE
  We examined the effects of an 8-week repeated-sprint (RS) training protocol on postexercise parasympathetic reactivation (PNSr) in healthy adults.
  
  
  METHODS
  Eighteen male adults (24.3 ± 3.7 years) were assigned to either of two groups. One group (n = 9) performed RS training (EXP, 3 times week(-1), 18 maximal all-out 15-m sprints interspersed with 17 s of passive recovery); the other served as the control group (CON, n = 9). Performance before, during, and after was assessed by measuring RS ability time (S dec) and total sprint time. The subjects were then seated for 10 min immediately after each trial and postexercise HR recovery (HRR), and vagal-related HR variability (HRV) indices were measured.
  
  
  RESULTS
  All subjects demonstrated a decrease in S dec. However, only EXP showed a decrease in total sprint time (-10.5 % of baseline value). Using a qualitative statistical analysis method, we found a likely to almost certain positive effect of RS training on HR. The mean of each HRR and HRV index indicated a greater change in PNSr in EXP than in CON (e.g. with a 78/22/1 % chance to demonstrate a positive/trivial/negative effect on HRR60s after RS training; 74/21/5 % on LN rMSSD5-10min). Large correlations were noted between the changes in S dec [r = 0.59, 90 % CI (0.43)], total sprint time [r = -0.61 (0.42)] and HRR60s.
  
  
  CONCLUSIONS
  RS training seems to be an effective method to improve postexercise PNSr in healthy adults. Also, HRR60s appears to be a method for evaluating positive adaption to RS training.
authors.affiliation: Department of Biomedical Sciences for Health, Università degli Studi di Milano, via Kramer 4/a, 20133, Milan, Italy. gianluca.vernillo@unimi.it.|CeRiSM, Research Center for Sport, Mountain and Health, University of Verona, Roveretos, TN, Italy. gianluca.vernillo@unimi.it.|Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Canada. gianluca.vernillo@unimi.it.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Vernillo
authors.affiliation: Department of Biomedical Sciences for Health, Università degli Studi di Milano, via Kramer 4/a, 20133, Milan, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Agnello
authors.affiliation: Department of Biosciences, Università degli Studi di Milano, Milan, Italy.|Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata (CIMMBA), Università degli Studi di Milano, Milan, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Barbuti
authors.affiliation: Department of Biomedical Sciences for Health, Università degli Studi di Milano, via Kramer 4/a, 20133, Milan, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Di Meco
authors.affiliation: Laboratory of Experimental Biochemistry and Molecular Biology, IRCCS Istituto Ortopedico Galeazzi, Milan, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Lombardi
authors.affiliation: Department of Biomedical Sciences for Health, Università degli Studi di Milano, via Kramer 4/a, 20133, Milan, Italy.|IRCCS Fondazione Don Carlo Gnocchi, Milan, Italy.
authors.forename: Giampiero
authors.initials: G
authors.lastname: Merati
authors.affiliation: Department of Biomedical Sciences for Health, Università degli Studi di Milano, via Kramer 4/a, 20133, Milan, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: La Torre
mesh_terms: D000328:Adult; D054874:Athletic Performance / Q000502:physiology; D001341:Autonomic Nervous System / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D012420:Running / Q000502:physiology*; D055815:Young Adult
keywords: Cardiac autonomic function; Heart rate recovery; Heart rate variability; Repeated-sprint ability