so if a person works out and they go light only and thats how they train, then you have a person who trains heavy most of the time, then you have a person who trains light, moderate, and heavy in their workouts, the light trainer wont have the strength to keep up with the guy who is lifting heavy, but the heavy trainer wont have the endurance and stamina to keep up with the light training guy, but the guy who trains light, moderate, and heavy everyday, will have the stamina to smoke the light training guy and the strength to smoke the heavy lifting guy, and he will have the stamina and endurance the heavy doesnt have, and will have the strength that the light trainer doesnt, but can still outrep and outstrenghth both, so this is why you should train, light, moderate, and heavy, with superset, regular sets, and giant sets, in your everyday workout.