Blood glucose minimum predicts maximal lactate steady state on running

Area of Science:

• Exercise Physiology
• Sports Science
• Metabolic Adaptations

Background:

• Maximal lactate steady state (MLSS) is a key indicator of endurance capacity.
• Identifying reliable predictors of MLSS is crucial for effective exercise prescription.
• The relationship between glucose metabolism during exercise and MLSS requires further investigation.

Purpose of the Study:

• To determine if the running speed at glucose minimum (GM) can predict MLSS in physically active men.
• To compare GM speed with lactate minimum (LM) speed and MLSS.
• To assess the practical applicability of GM speed for exercise intensity guidelines.

Main Methods:

• Thirteen physically active men performed a 1600-m time trial, incremental running tests to identify GM and LM speeds, and constant intensity exercise sessions to determine MLSS.
• Statistical analyses included repeated measures ANOVA and Bland and Altman plots.
• Speeds were analyzed in relation to 1600-m time trial performance.

Main Results:

• No significant differences were found between running speeds for GM, LM, and MLSS.
• High correlations were observed between GM and LM (r=0.984), GM and MLSS (r=0.947), and LM and MLSS (r=0.961).
• Bland and Altman plots indicated good agreement between GM, LM, and MLSS.

Conclusions:

• Running speed at GM is a reliable predictor of MLSS in physically active individuals.
• GM speed, occurring at approximately 84.4% of 1600-m speed, has practical implications for exercise prescription.
• The findings support the use of GM speed as a practical marker for setting endurance training intensities.