This method will help keep student athletes on task. Giving athletes a predetermined time at each station forces them to keep with the work/rest intervals that are prescribed. Using the same weight for all three to four sets makes the transition from set to set much easier and more efficient than with a system where plates need to be changed every set.
It is important for athletes to know what weight to use, when to add weight, what goals to aim for with each workout, and an understanding of when they are improving. With this system if the targeted reps are 10 (3x10) then once the athlete can complete all 3 sets of 10 with the same weight, then they know to increase their Working Max for the next week. If they don't complete all 3 sets of 10 reps then they use the same Working Max for the next workout. This allows them to know what weight they should use, when to add weight, and allows them to set goals for each workout.
When using more than 3 to 4 sets with the high school athlete, the quality of each additional set diminishes as a result of both mental and physical factors. As well as not being able to meet the time constraint of the prescribed workout.