title: Heart rate variability and psychometric responses to overload and tapering in collegiate sprint-swimmers.
abstract: OBJECTIVE
  The purpose of this study was to evaluate cardiac-parasympathetic and psychometric responses to competition preparation in collegiate sprint-swimmers. Additionally, we aimed to determine the relationship between average vagal activity and its daily fluctuation during each training phase.
  
  
  METHODS
  Observational.
  
  
  METHODS
  Ten Division-1 collegiate sprint-swimmers performed heart rate variability recordings (i.e., log transformed root mean square of successive RR intervals, lnRMSSD) and completed a brief wellness questionnaire with a smartphone application daily after waking. Mean values for psychometrics and lnRMSSD (lnRMSSDmean) as well as the coefficient of variation (lnRMSSDcv) were calculated from 1 week of baseline (BL) followed by 2 weeks of overload (OL) and 2 weeks of tapering (TP) leading up to a championship competition.
  
  
  RESULTS
  Competition preparation resulted in improved race times (p<0.01). Moderate decreases in lnRMSSDmean, and Large to Very Large increases in lnRMSSDcv, perceived fatigue and soreness were observed during the OL and returned to BL levels or peaked during TP (p<0.05). Inverse correlations between lnRMSSDmeanand lnRMSSDcvwere Very Large at BL and OL (p<0.05) but only Moderate at TP (p>0.05).
  
  
  CONCLUSIONS
  OL training is associated with a reduction and greater daily fluctuation in vagal activity compared with BL, concurrent with decrements in perceived fatigue and muscle soreness. These effects are reversed during TP where these values returned to baseline or peaked leading into successful competition. The strong inverse relationship between average vagal activity and its daily fluctuation weakened during TP.
authors.affiliation: The University of Alabama, Department of Kinesiology, United States. Electronic address: aflatt@crimson.ua.edu.
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Flatt
authors.affiliation: The University of Alabama, Department of Kinesiology, United States.
authors.forename: Bjoern
authors.initials: B
authors.lastname: Hornikel
authors.affiliation: The University of Alabama, Department of Kinesiology, United States.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Esco
mesh_terms: D000328:Adult; D054874:Athletic Performance / Q000502:physiology / Q000523:psychology; D003163:Competitive Behavior / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D018763:Muscle Fatigue; D063806:Myalgia / Q000175:diagnosis / Q000209:etiology / Q000523:psychology; D010275:Parasympathetic Nervous System / Q000502:physiology; D010465:Perception; D064797:Physical Conditioning, Human / Q000379:methods* / Q000502:physiology / Q000523:psychology; D011594:Psychometrics; D011795:Surveys and Questionnaires; D013550:Swimming / Q000502:physiology* / Q000523:psychology*; D055815:Young Adult
keywords: Autonomic; Fatigue; Monitoring; Parasympathetic; Smartphone