Maximum Phonation Time as a Predictor of Lactate Threshold during Intermittent Incremental Endurance Test

Area of Science:

• Exercise Physiology
• Sports Science
• Biophysics

Background:

• Lactate threshold is a key indicator of exercise intensity.
• Accurate prediction of lactate threshold is crucial for training optimization.
• Current methods for determining lactate threshold can be invasive or costly.

Purpose of the Study:

• To investigate the potential of Maximum Phonation Time (MPT) as a predictor of exercise intensity at the lactate threshold.
• To assess the correlation between MPT and physiological variables during graded exercise.
• To determine if MPT can be used as a simple, non-invasive method for monitoring exercise intensity.

Main Methods:

• Ten amateur football players underwent a graded cycling exercise test to exhaustion.
• Physiological variables including perceived exertion, cardiopulmonary values, and blood lactate were measured.
• Maximum Phonation Time (MPT) was recorded and correlated with physiological data.
• Binary logistic regression and ROC analysis were used to evaluate MPT's predictive capability for lactate threshold.

Main Results:

• MPT showed a significant correlation with measured physiological variables.
• ROC analysis indicated a sensitivity of 0.70 and specificity of 0.90 at an MPT cutoff of 9.5 seconds.
• An odds ratio of 1.45 suggested a 45% increased probability of exceeding the lactate threshold for each second decrease in MPT.

Conclusions:

• Maximum Phonation Time (MPT) may serve as a practical, non-invasive tool for estimating exercise intensity relative to the lactate threshold.
• MPT offers a potentially inexpensive method for monitoring training intensity in athletes.
• Further research with larger, diverse athletic populations is recommended to validate MPT's efficacy across different sports.