The Development of Functional Overreaching Is Associated with a Faster Heart Rate Recovery in Endurance Athletes.
OBJECTIVE
The aim of the study was to investigate whether heart rate recovery (HRR) may represent an effective marker of functional overreaching (f-OR) in endurance athletes.


RESULTS
Thirty-one experienced male triathletes were tested (10 control and 21 overload subjects) before (Pre), and immediately after an overload training period (Mid) and after a 2-week taper (Post). Physiological responses were assessed during an incremental cycling protocol to exhaustion, including heart rate, catecholamine release and blood lactate concentration. Ten participants from the overload group developed signs of f-OR at Mid (i.e. -2.1 ± 0.8% change in performance associated with concomitant high perceived fatigue). Additionally, only the f-OR group demonstrated a 99% chance of increase in HRR during the overload period (+8 ± 5 bpm, large effect size). Concomitantly, this group also revealed a >80% chance of decreasing blood lactate (-11 ± 14%, large), plasma norepinephrine (-12 ± 37%, small) and plasma epinephrine peak concentrations (-51 ± 22%, moderate). These blood measures returned to baseline levels at Post. HRR change was negatively correlated to changes in performance, peak HR and peak blood metabolites concentrations.


CONCLUSIONS
These findings suggest that i) a faster HRR is not systematically associated with improved physical performance, ii) changes in HRR should be interpreted in the context of the specific training phase, the athletes perceived level of fatigue and the performance response; and, iii) the faster HRR associated with f-OR may be induced by a decreased central command and by a lower chemoreflex activity.
Laboratory of Sport, Expertise and Performance (INSEP), EA, 7370, National Institute of Sport, Expertise and Performance, Paris, France.
Anaël
A
Aubry
Laboratory of Sport, Expertise and Performance (INSEP), EA, 7370, National Institute of Sport, Expertise and Performance, Paris, France.
Christophe
C
Hausswirth
Laboratory of Sport, Expertise and Performance (INSEP), EA, 7370, National Institute of Sport, Expertise and Performance, Paris, France; Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Tom Reilly building, L3 3AF, Liverpool, United Kingdom.
Julien
J
Louis
Sport and Exercise Discipline Group, Faculty of Health, University of Technology Sydney (UTS), Sydney, Australia.
Aaron J
AJ
Coutts
Laboratory of Sport, Expertise and Performance (INSEP), EA, 7370, National Institute of Sport, Expertise and Performance, Paris, France; Institute of Sport, Exercise and Active Living (ISEAL), School of Sport and Exercise Science, Victoria University, Melbourne, VIC, Australia.
Martin
M
Buchheit
Laboratory of Sport, Expertise and Performance (INSEP), EA, 7370, National Institute of Sport, Expertise and Performance, Paris, France.
Yann
Y
Le Meur
D000328:Adult; D056352:Athletes; D054874:Athletic Performance / Q000502:physiology; D001642:Bicycling / Q000502:physiology*; D002395:Catecholamines / Q000097:blood; D005221:Fatigue / Q000503:physiopathology; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007773:Lactates / Q000097:blood; D008297:Male; D010806:Physical Education and Training / Q000379:methods; D010807:Physical Endurance / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology; D012420:Running / Q000502:physiology*; D013550:Swimming / Q000502:physiology*; D013997:Time Factors
D002395:Catecholamines; D007773:Lactates