Which of the following is NOT a basic principle of conditioning?

Strengthening is indeed an important concept in conditioning, but it is not typically categorized as a basic principle of conditioning in the same way that nutrition, overloading, and progressive loading are.

Nutrition is fundamental because it provides the fuel that horses need to maintain and improve their physical condition. Adequate nutrition supports recovery, energy levels, and overall health, which are crucial for effective conditioning.

Overloading refers to the principle of gradually increasing the intensity and volume of exercise beyond the horse's current capacity, which is essential for promoting improvements in strength and endurance. It is about challenging the horse appropriately to enable adaptations that lead to better performance.

Progressive loading is closely related to overloading, emphasizing the ongoing adjustment of the training load to continuously stimulate improvements. This involves systematically increasing the intensity, duration, or frequency of workouts to ensure that the horse adapts and grows stronger and fitter over time.

In contrast, while strength gains occur as a result of proper conditioning, "strengthening" is not recognized as a standalone principle; rather, it is a result of effectively applying the other conditioning principles, such as overloading and progressive loading.