Performance and Physiological Effects of Race Pace-Based versus Heart Rate Variability-Guided Training Prescription in Runners

ABSTRACT Purpose The aim of the present study was to compare performance and physiological effects, and inter-individual response variation in performance and its physiological determinants between heart rate-based (HR), race pace-based (RP) and heart rate variability-based (HRV) training prescription approaches in recreational distance runners. Methods Twenty-eight participants completed a 6-week endurance training intervention after being randomly assigned to three groups: HR (n = 9), RP (n = 9), and HRV (n = 10) training prescription approaches. Results No interaction effects between groups were observed. Main time effects were found for absolute and relative V̇O 2 max, running economy (RE), speeds associated to the first (sVT1) and second ventilatory thresholds (sVT2) and 7 km time trial performance (TT) (p < 0.001, 0.88 ≤ d ≤ 2.67). The RP group improved TT ( p < 0.05, ES = 1.07), showing greater effectiveness in enhancing maximal aerobic speed and fat mass reduction, but did not consistently improve physiological parameters like sVT2 or RE. The HRV method increased sVT2 ( p < 0.01, ES = 1.34) and was more successful in boosting sVT1 and V̇O 2 max, although it resulted in an increase in fat mass. Training load was similar between groups ( p > 0.05), and a pyramidal training intensity distribution model was found in all groups. The lowest inter-individual response variation in TT was found in the RP group (coefficient of variation [CV] = 0.82), whereas the HRV group demonstrated a lower variation in relative V̇O 2 max (CV = 0.75) and sVT2 (CV = 0.79). Conclusions The RP approach is an effective and useful training prescription method for optimising performance in recreational runners, while the HRV method proves valuable for enhancing key physiological markers.