Controlled exponential growth is a stronger version of exponential growth. We prove that the homology of the free loop space ℒ X has controlled exponential growth in two important situations : (1) when X is a connected sum of manifolds whose rational cohomologies are not monogenic, (2) when the rational homotopy Lie algebra L X contains an inert element and ρ ( L X ) < ρ ( L X / [ L X , L X ] ) , where ρ ( V ) denotes the radius of convergence of V .