For some, they would feel immediate relief on body aches. 
Lifewave X39 is not a stimulant. A stimulant, e.g. Caffein, gives you a surge of energy immediately. You would feel a steady increase of energy overtime. If you are an athlete, you would notice the improvement in your stamina, speed, and speed of recovery. 
This is the reason why Michael Phelps chose Lifewave.