This study took a bunch of competitive football players, which means well-trained individuals who already practice the 40 yard dash and vertical jump as well as engage in weight lifting and looked at whether different types of squating can further improve their performance. The quarter squat group improved their performance significantly (by about 1/10s in the 40 yard dash and 11 cm in the vertical jump) while the full squat group did not. To me, this does not suggest that the type of strength training exercise is irrelevant for performance. Of course people can continue doing full squats and hope that they will respond differently to the participants in this study, but I’d rather go with what the research suggests is going to work. As a long jumper, I would surely benefit from being able to run faster and jump higher. Btw: I used to wonder why training videos of Greg Rutherford always seem to show him do squats, cleans and step ups with heavy weights but limited range of motion. Now I know why.