Final answer:
Blood lactate levels rise during anaerobic exercise when the intensity surpasses the oxygen supply, leading to oxygen debt and accumulation of lactate. Training can improve anaerobic performance and lactate tolerance, while muscle fatigue is influenced by various factors.
Step-by-step explanation:
Blood Lactate Concentration During Exercise
Blood lactate will begin to rise when exercise is performed at a rate that is more intense than what the oxygen supply can sustain, creating an oxygen debt. This occurs during anaerobic exercise, a type of physical activity that is intense enough to cause a lack of oxygen. During this exercise, glucose is broken down to produce adenosine triphosphate (ATP) without using oxygen, a process called glycolysis, which leads to increased lactic acid production and its accumulation as lactate in the blood.
The effectiveness of anaerobic activity can be improved through training, by increasing the body's ability to tolerate higher lactate levels and recover from oxygen debt. It's important to note that muscle fatigue involves more than just lactate levels, as it also includes energy availability, psychological factors, and more. Nonetheless, blood lactate levels are an important measure of the transition from aerobic to anaerobic metabolism during escalating exercise intensity.