International Journal of Exercise Science 11(2): 1105-1111, 2018. Heart rate variability (HRV) is an effective method to assess the influence of the autonomic nervous system, which may be directly linked to metabolic demand. The aim of the study was to determine if the second metabolic threshold can be identified by HRV. Thirteen athletes were assessed in cardiopulmonary exercise test with concomitant gas analysis. The RR intervals (RRi) were plotted in a spreadsheet for graphics analysis and the point at which there was a shift in the RRi curve was determined as RRiT2. The second ventilatory threshold (VT2) was used as the gold standard technique. A positive correlation was found in the test time (r = 0.84), heart rate (r = 0.97) and VO2 (r = 0.97) between the VT2 and HRV second threshold (RRiT2). All parameters identified by RRiT2 were lower than predicted by VT2 (p < 0.05).
Ribeiro, Gustavo S.; Pereira, Ubiratan R.; and Lopes, André L.
"Can Heart Rate Variability Predict the Second Metabolic Threshold in Young Soccer Players?,"
International Journal of Exercise Science: Vol. 11
2, Pages 1105 - 1111.
Available at: https://digitalcommons.wku.edu/ijes/vol11/iss2/15