It is easily possible to increase the strength of an person without increasing body his body weight.
And it is even possible, if not quite so easy, to increase strength while actually reducing body his body weight.
But little or nothing can be done to increase the actual strength of a particular muscle without also increasing mass, and thus the weight, of the same muscle.
To stimulate muscle growth there needs to be overload.
Without this nothing is possible.
Posted via Mobile Device