So, Does Vitamin C Increase Muscle Tone?

To answer your question of does vitamin c increase muscle tone, I looked at information from both exercise related sources and general, vitamin c related sources.

And I found that whilst there was reference to vitamin c increasing muscle tone in non-exercise related sources, there was none in the exercise specific sources. And the latter seemed to have better direct knowledge of studies done in relation to exercise recovery etc.

The exercise sources found that vitamin c may play a role indirectly in exercise recovery, and that it can help prevent muscle soreness. But likely this is true only if you are deficient in vitamin c. Vitamin c can however prevent infections, which is particularly good if as an athlete you are prone to them.

Vitamin c helps to regenerate other antioxidants, amongst other things, so it has a place in one's diet. But in asking 'Does vitamin c increase muscle tone"there is no evidence I have seen to suggest that it directly effects muscle tone. This is a good article on the effect of vitamin c in exercise, with a lot of studies cited.