This is an excerpt from Pilates and Conditioning for Athletes PDF by Amy Lademann & Rick Lademann.
Pilates and resistance training have a symbiotic relationship. Lifting weights is actually a neurologically driven movement working against external forces on your body while maintaining internal stability. The patterns of what we do under tension are for a specific amount of time or a specific number of reps. Pilates is similar in the sense that it uses the stabilizing muscles in movement patterns using internal forces, but it demands fluidity. While these may sound similar, Pilates and resistance training have two different applications on our central nervous system. Weightlifting heightens the sympathetic nervous system, which is a response to stress on the body. Pilates heightens the parasympathetic nervous system, which slows the heart rate and relaxes the musculature within it. These two methods together create balance in your body that cannot be duplicated. Put them together in your training program and you will notice very quickly that your body moves with a greater sense of ease because you will be able to balance the two components of the central nervous system. Either component tends to be overtrained if you focus on just one or the other.
All wins happen because the players on a team are prepared. The coach created a game plan and each player knew their role and perfected their skills. What is your goal? Is it to become stronger? Do you need to improve your flexibility and mobility? Are you working to become faster? Are you recovering from an injury and need to improve your agility and stability?