Final answer:
Endurance athletes can improve their lactate threshold by as much as 20% over 10 years of training, enhancing their performance and allowing them to sustain higher intensity efforts for longer periods.
Step-by-step explanation:
Training has been shown to significantly increase an athlete’s lactate threshold, which is the intensity of exercise at which lactate starts to accumulate in the blood stream. This is a key determinant of performance in endurance sports. Athletes can improve their lactate threshold by as much as 20% during 10 years of training. This increase allows athletes to perform at a higher intensity for a longer period before lactic acid buildup leads to fatigue.