Which factor does NOT contribute to an increase in strength endurance?

Improper nutrition does not contribute to an increase in strength endurance. Strength endurance relies on the muscles' ability to perform repeated contractions over time and is influenced by factors such as muscle fiber composition, training methods, and recovery. Proper nutrition is essential for fueling the body, repairing muscles, and optimizing performance. Without adequate nutrients, muscle recovery can be compromised, and energy levels may not support effective training sessions. In contrast, resistance training, high-rep bodyweight exercises, and stability training all promote adaptations beneficial for enhancing strength endurance through direct engagement of the muscle systems involved. Thus, while the other factors involve practices that foster improvement in strength endurance, improper nutrition hinders these processes.