Given a second order partial differential operator L satisfying the strong Hörmander condition with corresponding heat semigroup Pt, we give two different stochastic representations of dPtf for a bounded smooth function f . We show that the first identity can be used to prove infinite lifetime of a diffusion of 1 2 L, while the second one is used to find an explicit pointwise bound for the horizontal gradient on a Carnot group. In both cases, the underlying idea is to consider the interplay between sub-Riemannian geometry and connections compatible with this geometry.2010 Mathematics Subject Classification. 60D05, 35P99, 53C17, 47B25.