Abstract
Lactate is an acid produced as a byproduct of anaerobic glycolysis, and is used as an energy source for metabolism in the oxidative system. Initially classified as a waste product of cellular metabolism and a primary source of fatigue during exercise, lactate has recently been shown to play a large role in a number of vital physiological processes. Clinically, lactate has now been shown to interact with autonomic nervous system (ANS), and may be a valuable measure in diagnosing severity of disease. Currently, no research has been conducted examining the relationship between resting blood lactate (BL) and ANS activity relating to exercise. PURPOSE: The purpose of this study is to 1) determine the relationship between resting BL levels and ANS activity, and 2) investigate potential differences in resting BL measures between sedentary and well-trained individuals following a stressor. METHODS: All participants completed 2 trials separated by a minimum of 24-hours. On the first visit participants were informed they would not be performing exercise and were measured for resting values of heart rate variability (HRV) and BL. Blood lactate was measured with the participant in a seated position. For BL measures researchers acquired 0.7 μL of whole blood via a FORA sterile safety lancet. A Lactate Plus (L+, Nova Biomedical, USA) electrochemical lactate oxidase biosensor was used to calculate levels of lactate in whole blood. All HRV measurements were conducted using a Scosche Rhythm arm band sensor (Scosche Industries, Oxnard, CA) paired with the Elite HRV smartphone application. Participants were seated for the entirety of the 2-minute recording in a quiet room with maintaining a breathing rate of 12 breaths/minute. RMSSD was recorded for statistical analysis. On the second trial participants incurred a stressor by being made to believe they would be performing a maximal graded exercise test. Three minutes following the perceived stressor researchers collected resting HRV and BL measures. A Pearson product-moment correlation was performed to determine the relationship between BL and HRV while Mann-Whitney U test was used to determine differences between sedentary and advanced individuals for BL and HRV. Significance was set a priori at p < 0.05. RESULTS: 10 participants (male, n = 3; female, n = 7) completed all data collection procedures with 5 being classified as sedentary and 5 being classified as advanced. No significant relationship (p = 0.361) was found between HRV and BL. No significant differences were observed in BL (p = 0.525) response and HRV (p = 0.465) between the sedentary and advanced endurance athletes. CONCLUSIONS: Based on the small sample size the researchers could not determine significant differences between sedentary and advanced athletes with regard to lactate response to a stressor although BL increased an average of 2.0 ± 1.37 mmol/L in the advanced group. Further data is needed to fully determine the potential relationships that may exist between BL and HRV in both sedentary individuals and advanced endurance athletes.
Recommended Citation
Thompson, Lily and Crossland, Brett
(2025)
"Comparison of Lactate Response to Perceived Stress Between Sedentary Individuals & Advanced Endurance Athletes,"
International Journal of Exercise Science: Conference Proceedings: Vol. 2:
Iss.
17, Article 165.
Available at:
https://digitalcommons.wku.edu/ijesab/vol2/iss17/165