320kg isn't alot mate for the leg press, its only like 8 plates a side, i could do that last year at a age of twenty and all i was takin where just protein shakes and creatine. tell him to try and do that weight on the squats, i bet he cant even do half of that weight.
there are people at my gym that are doin 15 plates aside, that equals to 600 kg, now that is amazin but they are on juice though.