title: Monitoring athletic training status using the maximal rate of heart rate increase.
abstract: OBJECTIVE
  Reductions in maximal rate of heart rate increase (rHRI) correlate with performance reductions when training load is increased. This study evaluated whether rHRI tracked performance changes across a range of training states.
  
  
  METHODS
  Prospective intervention.
  
  
  METHODS
  rHRI was assessed during five min of cycling at 100W (rHRIcyc) and running at 8km/h (rHRIrun) in 13 male triathletes following two weeks of light-training (LT), two weeks of heavy-training (HT) and a two-day recovery period (RP). A five min cycling time-trial assessed performance and peak oxygen consumption (V˙O2peak).
  
  
  RESULTS
  Performance likely decreased following HT (Effect size±90% confidence interval=-0.18±0.09), then very likely increased following RP (0.32±0.14). rHRIcyc very likely decreased (-0.48±0.24), and rHRIrun possibly decreased (-0.33±0.48), following HT. Changes in both measures were unclear following RP. Steady-state HR was almost certainly lower (-0.81±0.31) during rHRIcyc than rHRIrun. A large correlation was found between reductions in performance and rHRIrun (r±90%; CI=0.65±0.34) from LT to HT, but was unclear for rHRIcyc. Trivial within-subject correlations were found between rHRI and performance, but the strength of relationship between rHRIrun and performance was largely associated with V˙O2peak following LT (r=-0.58±0.38).
  
  
  CONCLUSIONS
  Performance reductions were most sensitively tracked by rHRIrun following HT. This may be due to rHRIrun being assessed at a higher intensity than rHRIcyc, inferred from a higher steady-state HR and supported by a stronger within-subject relationship between rHRIrun and performance in individuals with a lower V˙O2peak, in whom the same exercise intensity would represent a greater physiological stress. rHRI assessed at relatively high exercise intensities may better track performance changes.
authors.affiliation: Alliance for Research in Exercise, Nutrition and Activity (ARENA), Sansom Institute for Health Research, University of South Australia, Australia. Electronic address: clint.bellenger@mymail.unisa.edu.au.
authors.forename: Clint R
authors.initials: CR
authors.lastname: Bellenger
authors.affiliation: Alliance for Research in Exercise, Nutrition and Activity (ARENA), Sansom Institute for Health Research, University of South Australia, Australia.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Thomson
authors.affiliation: Clinical Nutrition Research Centre, University of Newcastle, Australia.
authors.forename: Peter R C
authors.initials: PR
authors.lastname: Howe
authors.affiliation: Polar Electro Oy, Finland.
authors.forename: Laura
authors.initials: L
authors.lastname: Karavirta
authors.affiliation: Alliance for Research in Exercise, Nutrition and Activity (ARENA), Sansom Institute for Health Research, University of South Australia, Australia.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Buckley
mesh_terms: D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D001642:Bicycling / Q000502:physiology*; D016001:Confidence Intervals; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods*; D005221:Fatigue; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D011446:Prospective Studies; D012420:Running / Q000502:physiology*; D055815:Young Adult
keywords: Athletic performance; Autonomic nervous system; Heart rate; Overreaching