There is a similar question to this out there, but is NOT identical.
Does weight and/or body frame have anything to do with singing?
My question is : CAN fitness level and/or body size improve singing performance and sound quality? So the question doesn't refer to the initial body size, but to a change in size.
For example, swimming increases lung capacity + endurance, while bodybuilding can build a bigger core, maybe in turn increasing the resonance of the tone?
What are your experiences on this?