scholarly journals Detection of the Anaerobic Threshold in Endurance Sports: Validation of a New Method Using Correlation Properties of Heart Rate Variability

2021 ◽  
Vol 6 (2) ◽  
pp. 38
Author(s):  
Bruce Rogers ◽  
David Giles ◽  
Nick Draper ◽  
Laurent Mourot ◽  
Thomas Gronwald
Keyword(s):  
Heart Rate ◽  
Gas Exchange ◽  
Anaerobic Threshold ◽  
Ventilatory Threshold ◽  
Performance Status ◽  
Exchange Kinetics ◽  
And Performance ◽  
Correlation Properties ◽  
Gas Exchange Kinetics ◽  
Exchange Data

Past attempts to define an anaerobic threshold (AnT) have relied upon gas exchange kinetics, lactate testing and field-based evaluations. DFA a1, an index of heart rate (HR) variability (HRV) fractal correlation properties, has been shown to decrease with exercise intensity. The intent of this study is to investigate whether the AnT derived from gas exchange is associated with the transition from a correlated to uncorrelated random HRV pattern signified by a DFA a1 value of 0.5. HRV and gas exchange data were obtained from 15 participants during an incremental treadmill run. Comparison of the HR reached at the second ventilatory threshold (VT2) was made to the HR reached at a DFA a1 value of 0.5 (HRVT2). Based on Bland–Altman analysis and linear regression, there was strong agreement between VT2 and HRVT2 measured by HR (r = 0.78, p < 0.001). Mean VT2 was reached at a HR of 174 (±12) bpm compared to mean HRVT2 at a HR of 171 (±16) bpm. In summary, the HR associated with a DFA a1 value of 0.5 on an incremental treadmill ramp was closely related to that of the HR at the VT2 derived from gas exchange analysis. A distinct numerical value of DFA a1 representing an uncorrelated, random interbeat pattern appears to be associated with the VT2 and shows potential as a noninvasive marker for training intensity distribution and performance status.

scholarly journals A New Detection Method Defining the Aerobic Threshold for Endurance Exercise and Training Prescription Based on Fractal Correlation Properties of Heart Rate Variability

2021 ◽  
Vol 11 ◽  
Author(s):  
Bruce Rogers ◽  
David Giles ◽  
Nick Draper ◽  
Olaf Hoos ◽  
Thomas Gronwald
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Gas Exchange ◽  
Ventilatory Threshold ◽  
Intraclass Correlation ◽  
Fluctuation Analysis ◽  
Scaling Exponent ◽  
Low Intensity ◽  
Low Intensity Exercise ◽  
Correlation Properties

The short-term scaling exponent alpha1 of detrended fluctuation analysis (DFA a1), a nonlinear index of heart rate variability (HRV) based on fractal correlation properties, has been shown to steadily change with increasing exercise intensity. To date, no study has specifically examined using the behavior of this index as a method for defining a low intensity exercise zone. The aim of this report is to compare both oxygen intake (VO2) and heart rate (HR) reached at the first ventilatory threshold (VT1), a well-established delimiter of low intensity exercise, to those derived from a predefined DFA a1 transitional value. Gas exchange and HRV data were obtained from 15 participants during an incremental treadmill run. Comparison of both VO2 and HR reached at VT1 defined by gas exchange (VT1 GAS) was made to those parameters derived from analysis of DFA a1 reaching a value of 0.75 (HRVT). Based on Bland Altman analysis, linear regression, intraclass correlation (ICC) and t testing, there was strong agreement between VT1 GAS and HRVT as measured by both HR and VO2. Mean VT1 GAS was reached at 39.8 ml/kg/min with a HR of 152 bpm compared to mean HRVT which was reached at 40.1 ml/kg/min with a HR of 154 bpm. Strong linear relationships were seen between test modalities, with Pearson’s r values of 0.99 (p &lt; 0.001) and.97 (p &lt; 0.001) for VO2 and HR comparisons, respectively. Intraclass correlation between VT1 GAS and HRVT was 0.99 for VO2 and 0.96 for HR. In addition, comparison of VT1 GAS and HRVT showed no differences by t testing, also supporting the method validity. In conclusion, it appears that reaching a DFA a1 value of 0.75 on an incremental treadmill test is closely associated with crossing the first ventilatory threshold. As training intensity below the first ventilatory threshold is felt to have great importance for endurance sport, utilization of DFA a1 activity may provide guidance for a valid low training zone.

Effect of interbreath fluctuations on characterizing exercise gas exchange kinetics

1987 ◽  
Vol 62 (5) ◽  
pp. 2003-2012 ◽  
Author(s):  
N. Lamarra ◽  
B. J. Whipp ◽  
S. A. Ward ◽  
K. Wasserman
Keyword(s):  
Gas Exchange ◽  
Least Squares ◽  
Kinetic Parameters ◽  
Nonlinear Least Squares ◽  
Cycle Ergometer ◽  
Gaussian Stochastic Process ◽  
Co2 Output ◽  
Nonsteady State ◽  
Exchange Kinetics ◽  
Gas Exchange Kinetics

Breathing has inherent irregularities that produce breath-to-breath fluctuations (“noise”) in pulmonary gas exchange. These impair the precision of characterizing nonsteady-state gas exchange kinetics during exercise. We quantified the effects of this noise on the confidence of estimating kinetic parameters of the underlying physiological responses and hence of model discrimination. Five subjects each performed eight transitions from 0 to 100 W on a cycle ergometer. Ventilation, CO2 output, and O2 uptake were computed breath by breath. The eight responses were interpolated uniformly, time aligned, and averaged for each subject; and the kinetic parameters of a first-order model (i.e., the time constant and time delay) were then estimated using three methods: linear least squares, nonlinear least squares, and maximum likelihood. The breath-by-breath noise approximated an uncorrelated Gaussian stochastic process, with a standard deviation that was largely independent of metabolic rate. An expression has therefore been derived for the number of square-wave repetitions required for a specified parameter confidence using methods b and c; method a being less appropriate for parameter estimation of noisy gas exchange kinetics.

scholarly journals Cardiac Reserve and Pulmonary Gas Exchange Kinetics in Patients With Stroke

Stroke ◽  
2008 ◽  
Vol 39 (11) ◽  
pp. 3102-3106 ◽  
Author(s):  
Corey R. Tomczak ◽  
Anwar Jelani ◽  
Robert G. Haennel ◽  
Mark J. Haykowsky ◽  
Robert Welsh ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Pulmonary Gas Exchange ◽  
Cardiac Reserve ◽  
Exchange Kinetics ◽  
Gas Exchange Kinetics

scholarly journals Heart rate deflection point as a non-invasive method to determine the anaerobic threshold in trained elderly women in the aquatic environment

2020 ◽  
Vol 19 (6) ◽  
pp. 468
Author(s):  
Luana Siqueira Andrade ◽  
Mariana Silva Häfele ◽  
Gustavo Zaccaria Schaun ◽  
Samara Nickel Rodrigues ◽  
Mariana Borba Gomes ◽  
...  
Keyword(s):  
Heart Rate ◽  
Anaerobic Threshold ◽  
Perceived Exertion ◽  
Elderly Women ◽  
Ventilatory Threshold ◽  
Altman Analysis ◽  
Incremental Test ◽  
Bland Altman Analysis ◽  
Water Based ◽  
Invasive Method

Introduction: The anaerobic threshold (AT) determination is important for individualizing the aerobic training prescription. Objective: To compare and verify the agreement between oxygen uptake (VO2), heart rate (HR), and rate of perceived exertion (RPE) at the AT determined by the ventilatory threshold (VT) and heart rate deflection point (HRDP) methods during an aquatic incremental test in trained older women. Methods: Nine elderly women (64.3 ± 4.4 years) engaged in a water-based training program in the last three months performed a maximum incremental test using the water-based stationary running exercise. The test started at a 70 bpm cadence for 2 min, followed by 15 bpm increments every 2 min until exhaustion. VO2, HR and RPE were measured throughout the test and the AT was identified for each method (i.e., VT and HRDP) by three experienced physiologists. Paired t-test and Bland-Altman analysis were used for data analysis (α=0.05). Results: There was no difference between the VT and HRDP methods (p>0.05) and the Bland-Altman analysis showed acceptable agreement between them for all investigated outcomes (VO2: 22.9 ± 5.1 vs. 23.5 ± 4.7 ml.kg-1.min-1, IC95%: -3-+4 ml.kg-1.min-1; HR: 147 ± 11 vs. 147 ± 11 bpm, IC95%: -9-+8 bpm; RPE: 16 ± 1 vs. 16 ± 1, IC95%: -2-+3). Conclusion: Based on these findings, both HR and RPE determined by the HRDP can be used as valid parameters and practical tools for field prescription of intensity during water-based exercises in elderly trained women.Keywords: exercise, aging, exercise test, hydrotherapy, oxygen consumption. 

Sign in / Sign up

Export Citation Format

Share Document