Agreement Between Results of the Lamberts and Lamberts Submaximal Cycle Test and Heart Rate Variability to Indicate Training-Induced Load in Elite Road Cyclists

Visagie, N, Coetzee, B, and Kramer, M. Agreement between results of the Lamberts and Lamberts Submaximal Cycle Test and heart rate variability to indicate training-induced load in elite road cyclists. J Strength Cond Res XX(X): 000–000, 2026—The aim of this study was to assess the agreement between the Lamberts and Lambert submaximal cycle test (LSCT) results and heart rate variability (HRV) to indicate training-induced load in road cyclists. Weekly LSCT tests and daily HRV morning readings of 13 elite, male road cyclists (aged 22.63 ± 3.31 years) were monitored over a seven-week precompetitive training period. In addition, a repeated measures correlation analysis (RMCorr) was used to evaluate the overall common intraindividual associations between the LSCT-related and HRV-related variables. As such, a significant moderate positive relationship was identified between Total HRV and stage 3 mean power output (W) (RMCorr = 0.41, p = 0.000), with weaker relationships observed between Total HRV and stages 2 (RMCorr = −0.23, p = 0.029) and 3 mean exercise HR (b·min −1 ) (RMCorr = 0.32; p = 0.002). Similarly, significant weak, negative correlations were identified between NN50, pNN50 (%), and the rate of perceived exertion of stages 2 (RMCorr = −0.30, p = 0.004; RMCorr = −0.25, p = 0.016) and 3 (RMCorr = −0.39, p = 0.000; RMCorr = −0.27, p = 0.008). Furthermore, significant weak negative and positive relationships, respectively, were obtained between NN50, absolute (b·min −1 ) (RMCorr = −0.27, p = 0.008), and relative HRR 90 (%) (RMCorr = 0.28, p = 0.007). In conclusion, although HRV parasympathetic nervous system indicators predict responses of the LSCT performance and load indicators; the low practical significance of results challenges the notion of using morning HRV parameters as proxies for the outcome measures of the LSCT.