title: Heart rate variability in trotters during different training periods.
abstract: BACKGROUND
  Endurance training induces changes in autonomic nervous system functions. High intensity training includes the risk of overtraining, in man and horse. Heart rate variability (HRV) is a noninvasive measurement of the autonomic regulation of the heart rate, which is quick and easy to measure with modern telemetric technology.
  
  
  OBJECTIVE
  Since HRV is affected by changes in the autonomic nervous system, it might be an early stage indicator of poor recovery from a previous bout of exercise or overreaching or overtraining in horses in general.
  
  
  METHODS
  The aim of the study was to monitor recovery and the possible overtraining status in horses by measuring HRV. The measurements reflected the responses of the previous day activities during different training periods including basic training, precompetition and competition during a one-year follow-up.
  
  
  RESULTS
  HRV was at the highest during precompetition period (P<0.05) and it decreased significantly during competition period (P<0.05), indicating an increased stress load in the competition period. Walking increased HRV significantly compared to complete rest or jogging as previous day activities during basic training and precompetition periods (P<0.05). This finding suggests that horses are more relaxed during moderate exercise than standing still or anaerobic exercise.
  
  
  CONCLUSIONS
  HRV can be used to monitor the cardiovascular responses to training in horses but confirmatory measures may also be required in addition to HRV to exclude other possible causes of underperformance.
authors.affiliation: Equine Information Centre, P.O. Box 1627, 70211 Kuopio, Finland.
authors.forename: S
authors.initials: S
authors.lastname: Kinnunen
authors.forename: R
authors.initials: R
authors.lastname: Laukkanen
authors.forename: J
authors.initials: J
authors.lastname: Haldi
authors.forename: O
authors.initials: O
authors.lastname: Hanninen
authors.forename: M
authors.initials: M
authors.lastname: Atalay
mesh_terms: D000818:Animals; D001341:Autonomic Nervous System / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006736:Horses / Q000097:blood / Q000502:physiology*; D008297:Male; D010805:Physical Conditioning, Animal / Q000379:methods* / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology; D010809:Physical Fitness / Q000502:physiology; D012146:Rest / Q000502:physiology