Final answer:
In training, 'hitting a wall' refers to a Plateau, where progress ceases despite continued efforts. This can result from overtraining, lack of rest, or insufficient workout variation, and is not directly linked to muscle recruitment, recovery heart rate, or nutrition.
Step-by-step explanation:
The term “hitting a wall” in the context of training refers to Plateau. When someone hits a wall, it means that they have reached a point in their training where they no longer see progress or improvement despite continuing to train. This feeling of stagnation can be caused by a number of factors, such as overtraining, inadequate rest, or lack of variation in the workout routine. It doesn’t relate directly to muscle recruitment, recovery heart rate, or nutrition, although these elements can certainly influence one's ability to progress in their training.
For instance, in the military training scenario described in Figure 15.5.6, new recruits might hit a plateau if they overexert themselves without proper conditioning. The drill instructor's encouragement is crucial for motivation, but it's also necessary to balance effort with recovery to avoid plateaus and ensure ongoing improvements.