The Effects of a Peaking Protocol on Heart Rate Variability and its Predictive Associations with Wilks Coefficient in Competitive Powerlifters

Powerlifting  competition  is  comprised  of  three barbell lifts: squat, bench press, and deadlift that are  all  completed  in  a  single  day  and  summed together,  ultimately  normalized  to  the  lifter’s  body  weight  via  the  Wilks  Coefficient.  This  figure  is then  subsequently  employed  to  determine  the “best” athlete in that meet. During the competition preparation,  powerlifters  often  undergo  peaking protocols  which  include  physiologically  taxing overreach and low-volume, recovery-focused taper phases to collectively induce super-compensatory strength  adaptations.  Heart  rate  variability  (HRV) has emerged as an easily accessible, user-friendly biomarker for autonomic nervous system-associated fatigue and readiness. Therefore, the purpose of this observational study was to investigate the potential impact of a peaking protocol on fatigue/readiness via HRV measurements and its possible relationship with  competitive  powerlifting  performance.  Daily measurements  of  HRV  were  taken,  each  morning,  using the HRV4Trainning smartphone application by nineteen competitive powerlifters (26.16±4.56 years) from 14-days prior to a peaking protocol, throughout individual  peaking  phases,  on  meet  day,  and  14-days following competition. A quadratic regression was  used  to  determine  the  predictability  of  HRV measurements  and  powerlifting  performance.  The change  in  HRV  from  competition  day  to  baseline was  found  to  be  a  significant  predictor  of  Wilks coefficient  (p=0.038, R2=0.336;  mean±SE  log-transformed  root  mean  square  of  successive  R-R intervals  [lnRMSSD]  =  -51.98±22.23).  Although extrapolations  of  the  present  study  are  limited  by inherent subject peaking protocol variability, these data  suggest  HRV  may  nonetheless  represent  a viable means to modulate individual athlete training programs to promote recovery.