Attentive processes, blood lactate and CrossFit^®

Area of Science:

• Exercise Physiology
• Sports Science
• Cognitive Neuroscience

Background:

• CrossFit® training is known for its high intensity and potential to induce significant physiological stress.
• Elevated blood lactate is a common biomarker of intense anaerobic exercise.
• The impact of exercise-induced metabolic changes on cognitive functions, particularly attention, requires further investigation.

Purpose of the Study:

• To investigate the effect of blood lactate accumulation during a CrossFit® session on attentional performance.
• To assess how lactate influences reaction time and divided attention in CrossFit® athletes.

Main Methods:

• Fifteen male CrossFit® athletes participated in a standardized high-intensity workout (WOD 15.5).
• Measurements included blood lactate, blood glucose, reaction time, and dual-task performance (divided attention) at rest, post-exercise, and 15 minutes post-exercise.
• The WOD involved rowing calories and barbell squats with specific loads and repetition schemes.

Main Results:

• Pre-exercise blood lactate levels were elevated (mean 4.5 mmol/L), significantly increasing post-exercise (mean 13.8 mmol/L).
• Cognitive performance, including reaction time and dual-task execution (errors and omissions), significantly worsened as blood lactate levels increased.
• Blood glucose levels showed no significant changes during the exercise session.

Conclusions:

• High blood lactate levels, even at rest, are associated with reduced attentional capacity in CrossFit® athletes.
• Intense CrossFit® exercise exacerbates these attentional deficits, impacting reaction time and divided attention.
• These findings suggest that CrossFit® practitioners may experience limitations in cognitive functions crucial for performance and safety.