Substatic manifolds arise naturally in General Relativity as spatial slices of static spacetimes satisfying the Null Energy Condition. We will show that the substatic condition captures a large class of interesting model solutions. We will then discuss the strong connection between the substatic condition and the Bakry-Emery Ricci tensor. This will allow us to perform comparison arguments leading to a Bishop-Gromov monotonicity and a splitting theorem for this class of manifolds. This is a work in progress with Mattia Fogagnolo.