Monitoring training in women's volleyball: Supine or seated heart rate variability?

We aimed to examine changes in resting heart rate variability, submaximal exercising heart rate (HRex), countermovement-jump height (CMJ), perceptual wellbeing, and internal load throughout preparatory training in elite women's volleyball players. We also aimed to determine which HRV measurement position (supine vs. seated) provided greater associations with the various markers of training adaptation. Thirteen players (age = 25.8 ± 3.0 years, height = 178.1 ± 6.7 cm, weight = 69.7 ± 7.6 kg) were monitored throughout four successive training camps preceding the Asia Cup. Daily measures of the root-mean square of successive differences were used to calculate the mean (LnRMSSD_M) and coefficient of variation (LnRMSSD_CV) for each camp. Averages were also determined for Hooper's Index and session ratings of perceived exertion (sRPE). HRex and CMJ were tested at the start of each camp. RESULTS: Seated LnRMSSD_CV, HRex, CMJ, and sRPE increased at camp 3 (p < 0.05), then reverted to values similar to camp 2. Changes in seated LnRMSSD_M were associated with changes in HRex (r = -0.68 to -0.71, p < 0.05). Occasional associations (p < 0.05) were observed between LnRMSSD_CV and Hooper's Index (r = 0.59) and CMJ (r = -0.57), and changes in HRex (r = 0.69) and HRR (r = -0.62). CONCLUSIONS: A reduced cardiorespiratory response to a standardized submaximal workload was associated with increased seated LnRMSSD_M. Higher seated LnRMSSD_CV was observed in response to increased sRPE and was often associated with decrements in various status markers. Seated LnRMSSD provided more associations with indicators of training adaptation than supine measures.