[en] We show how to improve the molecular dynamics step of Hybrid Monte Carlo, both by tuning the integrator using Poisson brackets measurements and by the use of force gradient integrators. We present results for moderate lattice sizes. We have presented a novel way of tuning an integrator, together with a practical example using a moderate lattice size. This tuning procedure can be used for all lattice gauge and fermionic actions. We are working towards a general implementation of the calculation of Poisson brackets and force gradient terms in Chroma. In the near future we will consider the tuning of HMC simulations on larger lattices and smaller quark masses, and we will also consider other widely used lattice actions.