What specific physiological adaptations occur in professional cyclists when they maintain a high volume of Zone 2 training during the pre-season, and how do these adaptations impact their performance in high-intensity events?
Is the prevailing wisdom that Zone 2 training is primarily for building endurance and increasing mitochondrial density still valid, or have recent studies shown that it also has a significant impact on other aspects of a cyclists physiology, such as increased capillarization or improved muscle fiber recruitment patterns?
How do coaches and trainers balance the need for high-volume Zone 2 training with the risk of overreaching or overtraining, particularly in athletes who are already highly adapted to endurance exercise?
Are there any specific markers or indicators that coaches use to determine when an athlete has reached an optimal level of Zone 2 adaptation, and how do they adjust training accordingly?