" That means to push very heavy weight, repeatedly, and to constantly strive to elevate both your baseline numbers and the total weight lifted at the workout—until you start to reach a natural limit relative to your competitive goals. This will deliver improvements in strength and subsequent improvements in endurance performance, and also maximize the hormonal, anti-aging benefits of the workout. "

― Mark Sisson , Primal Endurance: Revolutionize Your Training Approach to Drop Excess Body Fat, Manage Stress, Preserve Health, and Go a Lot Faster!