Rafael Nadal is on the exact opposite end of the spectrum as Roger Federer while he practices: full out and 100% all the time. In this video you see him crushing forehand after forehand at pretty high intensity. This is something that I saw him do over and over again while hitting various strokes, sometimes getting run all over the court by his coach while he was hitting. During this particular drill his coach was actually at the net volleying these huge shots back, impressive hands!