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A Rapidly Incremented Tethered-Swimming Maximal Protocol for Cardiorespiratory Assessment of Swimmers

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The ventilatory response to incremental exercise: is it one or two breakpoints?

Daniel G Carey¹, German J Pliego, John L Rohwer

¹Health and Human Performance Department, University of St. Thomas, St. Paul, Minnesota, USA. dgcarey@stthomas.edu

Journal of Strength and Conditioning Research

|October 2, 2010

Summary

The ventilatory breakpoint (VE) during exercise is best modeled by a double breakpoint (BP2), not a single breakpoint (BP1) or exponential function (EXP). Visual assessment of the VE breakpoint is unreliable and invalid.

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Published on: October 17, 2018

Area of Science:

Exercise Physiology
Sports Science
Biostatistics

Background:

The ventilatory breakpoint (VE) is a key indicator of exercise intensity and performance.
Accurate identification of the VE breakpoint is crucial for training and physiological assessment.
Current methods for identifying the VE breakpoint include single breakpoint (BP1), double breakpoint (BP2), and exponential function (EXP) models, alongside visual assessment.

Purpose of the Study:

To determine the optimal model (BP1, BP2, or EXP) for representing the ventilatory breakpoint (VE) during incremental exercise.
To evaluate the validity and reliability of visually assessing the VE breakpoint compared to computational models.

Main Methods:

49 endurance athletes (runners and triathletes) performed a maximal oxygen uptake test on a treadmill using a modified Bruce protocol.
Ventilatory data (VE) was analyzed using BP1, BP2, and EXP models to compare mean square error (MSE).
Visual assessment of the VE breakpoint was compared against a computer model for validity and assessed for inter- and intra-evaluator reliability.

Main Results:

The double breakpoint (BP2) model showed significantly lower mean square error (MSE) for VE compared to the single breakpoint (BP1) model.
The exponential function (EXP) model had significantly higher MSE for VE than both BP1 and BP2 models.
Visual assessment demonstrated poor validity (71.7% misclassification) and low inter- (30.6%) and intra-evaluator (59.7%) reliability.

Conclusions:

The ventilatory breakpoint (VE) during incremental exercise is best represented by a double breakpoint (BP2) model.
Visual assessment of the VE breakpoint is neither valid nor reliable for exercise physiology analysis.
These findings emphasize the importance of using appropriate computational models for accurate VE breakpoint determination.