Hyperlactemia induction modes affect the lactate minimum power and physiological responses in cycling

Area of Science:

• Exercise Physiology
• Sports Science
• Biochemistry

Background:

• Lactate minimum intensity (LMI) is a crucial physiological marker in endurance athletes.
• Understanding factors influencing LMI, such as hyperlactemia and acidosis, is vital for performance optimization.
• Previous research has not fully elucidated the impact of different induction methods on LMI and associated physiological responses.

Purpose of the Study:

• To investigate the influence of varying hyperlactemia and blood acidosis induction methods on lactate minimum intensity (LMI).
• To compare physiological parameters at LMI across different exercise protocols in trained cyclists and triathletes.

Main Methods:

• Twenty recreationally trained male cyclists and triathletes performed three lactate minimum tests.
• Exercise protocols included a graded exercise test (GXT), a Wingate test (WAnT), and two consecutive Wingate tests (2 × WAnTs).
• Measurements included lactate minimum intensity (LMI), blood lactate, venous pH, bicarbonate concentration ([HCO3]), oxygen uptake, and pulmonary ventilation.

Main Results:

• Lactate minimum intensity (LMI) was significantly higher following the 2 × WAnTs protocol compared to GXT and single WAnT.
• The 2 × WAnTs protocol resulted in lower venous pH and bicarbonate concentration ([HCO3]) but higher blood lactate levels compared to GXT and WAnT.
• Oxygen uptake and pulmonary ventilation at LMI did not differ significantly across the protocols.

Conclusions:

• The mode of hyperlactemia and acidosis induction significantly affects blood pH, lactate, and bicarbonate levels.
• These alterations in physiological markers consequently influence the determined lactate minimum intensity (LMI) and associated parameters.
• Exercise protocol selection is critical when assessing LMI and related physiological responses in athletes.