What Is The Optimal Lactate Threshold Intensity At Which To Implement High-intensity Interval Training (HIIT) In Order To Maximize Mitochondrial Biogenesis And Electron Transport Chain Function In The Vastus Lateralis Muscle Of Elite Distance Runners, Taking Into Account Individual Variability In Muscle Fiber Type Distribution And Aerobic Capacity?

The optimal intensity for implementing high-intensity interval training (HIIT) to maximize mitochondrial biogenesis and electron transport chain function in elite distance runners is around the second lactate threshold, typically corresponding to 85-90% of an individual's VO2 max. This intensity strikes a balance between stimulating mitochondrial growth and avoiding excessive fatigue. Personalization is crucial, considering individual variations in muscle fiber type and aerobic capacity. Monitoring through VO2 max or lactate threshold tests can help tailor the intensity for each runner. Thus, HIIT sessions should be designed around this personalized intensity to enhance endurance performance effectively.