Lactate threshold refers to the maximum sustained effort your body can maintain for an extended period of time usually around 45-60 minutes. It’s essentially your body’s redline, and it’s more than 95% accurate at predicting race finish order.
Training (or racing) over the redline can only last for so long, due to the anaerobic contribution to your muscles, which increases based upon intensity and duration of your workout. Eventually your body is forced to slow down or bonk altogether. But always training under the redline results in never learning to rev the engine high enough, sacrificing speed and limiting endurance.
ENDURANCE