title: Maximal rate of increase in heart rate during the rest-exercise transition tracks reductions in exercise performance when training load is increased.
abstract: OBJECTIVE
  Heart rate kinetics are faster in well-trained athletes at exercise onset, indicating sensitivity to training status, but whether they track performance changes due to changes in training load is unknown.
  
  
  METHODS
  Randomised, counterbalanced, cross-over.
  
  
  METHODS
  17 cyclists completed two weeks of light and two weeks of heavy training. The day after each training period heart rate was recorded during 5 min cycling at 100 W to determine the maximal rate of heart rate increase. Participants then performed a 5 min cycle time-trial after which heart rate recovery was determined.
  
  
  RESULTS
  Work during 5 min cycle time-trial decreased 3.5% (P<0.04) in participants (n=8) who increased training load (completed light training then heavy training) and, although maximal rate of heart rate increase did not change (P=0.27), within-individual changes in work were correlated with changes in maximal rate of heart rate increase (r=0.87, P=0.005). Work during 5 min cycle time-trial increased 6.5% (P<0.001) in 9 participants who decreased training load (completed heavy training then light training) and maximal rate of heart rate increase increased 28% (P=0.002) but the changes in maximal work were not related to changes in rate of heart rate increase (r=0.32, P=0.40). Heart rate recovery tended to track changes in 5 min cycle time-trial work following increases and decreases in training load (r=0.65-0.75, P=0.03-0.08).
  
  
  CONCLUSIONS
  Maximal rate of heart rate increases during cycling at 100 W tracks reductions in exercise performance when training load is increased, but not performance improvements when training loads are reduced. Maximal rate of heart rate increase may be a useful adjunct to heart rate recovery for tracking changes in exercise performance.
authors.affiliation: University of South Australia, Adelaide, Australia.
authors.forename: Maximillian J
authors.initials: MJ
authors.lastname: Nelson
authors.affiliation: University of South Australia, Adelaide, Australia.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Thomson
authors.affiliation: University of South Australia, Adelaide, Australia.
authors.forename: Daniel K
authors.initials: DK
authors.lastname: Rogers
authors.affiliation: University of South Australia, Adelaide, Australia.
authors.forename: Peter R C
authors.initials: PR
authors.lastname: Howe
authors.affiliation: University of South Australia, Adelaide, Australia. Electronic address: jon.buckley@unisa.edu.au.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Buckley
mesh_terms: D000328:Adult; D054874:Athletic Performance; D001642:Bicycling / Q000502:physiology*; D018592:Cross-Over Studies; D015444:Exercise; D006339:Heart Rate; D006801:Humans; D008297:Male; D064797:Physical Conditioning, Human
keywords: Cardiac autonomic function; Exercise performance; Fatigue; Heart rate recovery; Training load