Why might a personal trainer use progressive resistance training?

Progressive resistance training is a method used by personal trainers to help clients continuously improve their strength and fitness levels. By gradually increasing the amount of resistance or load applied during exercises, this approach challenges the muscles in a way that encourages adaptation and growth.

When the body becomes accustomed to a certain level of resistance, it can lead to a plateau in progress, where clients may not experience further gains in strength or muscle size. By using progressive resistance training, trainers can combat this adaptation by systematically increasing the demands placed on the muscles, thereby promoting continued improvements in performance and preventing stagnation.

The other options do not align with the primary purpose of progressive resistance training. Maintaining the same workout would not facilitate growth or adaptation, extending recovery periods is more associated with workout design rather than resistance progression, and while energy expenditure is an important factor in training, the focus of progressive resistance is not exclusively on increasing energy expenditure without improving efficiency.