We study the cosmological FRW flat solutions generated in general massive gravity theories .
Such a model are obtained adding to the Einstein General Relativity action a peculiar non derivative potentials , function of the metric components , that induce the propagation of five gravitational degrees of freedom .
This large class of theories includes both the case with a residual Lorentz invariance as well as the case with rotational invariance only .
It turns out that the Lorentz-breaking case is selected as the only possibility .
Moreover it turns out that that perturbations around strict Minkowski or dS space are strongly coupled .
The upshot is that even though dark energy can be simply accounted by massive gravity modifications , its equation of state w _ { \text { eff } } has to deviate from -1 .
Indeed , there is an explicit relation between the strong coupling scale of perturbations and the deviation of w _ { \text { eff } } from -1 .
Taking into account current limits on w _ { \text { eff } } and submillimiter tests of the Newton ’ s law as a limit on the possible strong coupling scale , we find that it is still possible to have a weakly coupled theory in a quasi dS background .
Future experimental improvements on short distance tests of the Newton ’ s law may be used to tighten the deviation of w _ { \text { eff } } form -1 in a weakly coupled massive gravity theory .