Heart rate deflection point (HRDP), identified as the second breakpoint in the "intensity / heart rate" relationship, is indicative of the anaerobic threshold (AT). This point can be determined via bi-segmental linear regression (2SEG) or through use of the maximal distance model (D-max); however, the relationship between these methods has yet to be investigated 2. Purpose: To compare the use of 2SEG and D-max methods to determine HRDP and to examine the relationship between these values with a metabolic threshold, respiratory compensation point (RCP), as well as running performance [5,000 meter treadmill time trial (5Ktime)]. Methods: Nineteen recreationally active men (n=9, 25.56±3.17y, 1.77±0.05 m, 83.52±6.77 kg, 48.98±7.37 ml·kg·min-1) and women (n=10, 22.78±2.11 y, 1.64±0.07 m, 62.28±6.20 kg, 42.32±4.13ml·kg·min-1) were recruited for this study. Participants completed two experimental trials, consisting of a graded exercise test to exhaustion (GXT) and 5,000m time trial on the treadmill. Estimates of HRDP and RCP were calculated from data collected during the GXT. One-way repeated measures analysis of variance was used to compare HRDP found through 2SEG (HRDP2SEG), HRDP found through D-max (HRDPD-max), and RCP. Pearson product moment correlations were used to examine the relationship between variables (HRDP2SEG, HRDPD-max, RCP, and 5Ktime). Results: No differences were found between HRDP2SEG (176.70±9.40 bpm), HRDPD-max (178.18±6.85 bpm), and RCP (176.92±6.63 bpm) (p = 0.533). Strong correlations were found between HRDP2SEG and HRDPD-max (r = 0.831, p < 0.0001), RCP and HRDP2SEG (r = 0.650, p = 0.003), and RCP and HRDPD-max (r = 0.619, p = 0.005). No relationship was found between 5Ktime and HRDP2SEG (r = 0.419, p = 0.074), HRDPD-max (r = 0.241, p = 0.321), or RCP (r = 0.193, p = 0.429). Similar limits of agreement were found for all comparisons (HRDP2SEG and RCP, p = 0.070; HRDPD-max and RCP, p = 0.868; HRDP2SEG and HRDPD-max, p = 0.029), however, systematic bias was found between HRDP2SEG and HRDPD-max. Conclusion: Based on these results, HRDP2SEG and HRDPD-max could potentially be used interchangeably as methods to determine HRDP. However, the potential for systematic bias must be taken into consideration. Additionally, the results indicate that RCP and HRDP may provide similar estimates of the anaerobic threshold, but none of these thresholds appear to be related to 5Ktime on a treadmill.
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Master of Science (M.S.)
College of Education and Human Performance
Educational and Human Sciences
Sport & Exercise Science; Applied Exercise Physiology
Length of Campus-only Access
Masters Thesis (Open Access)
Baker, Kayla, "Mathematical Modeling of Heart Rate Deflection Point in Relation to Respiratory Compensation and Treadmill Running Performance" (2016). Electronic Theses and Dissertations. 4897.