Final answer:
The minimum required amount of training an athlete must perform to achieve their goal is known as the 'threshold of training', representing the minimum training load needed for improvement.
Step-by-step explanation:
The minimum required amount of training an athlete must perform to achieve their goal is called the threshold of training. This concept signifies the least amount of exercise or training load needed to see an improvement in fitness or performance. It's important for athletes to understand their personal threshold to ensure they are training effectively without overtraining, which can lead to injuries or burnouts. For athletes looking to elevate their performance, it's essential to consistently train just above this threshold. However, finding the right balance is key, as training too much can be just as detrimental as training too little. The idea is to stimulate adaptation and improvement, yet allow enough time for recovery.