A good upper body on the flat always goes hand-in-hand with a strong base of support. In order to ensure there is a solid base of support, which in turn will develop an independent upper body, the number-one thing that we encourage all riders to practice is lots of work without stirrups. The upper body depends on the lower leg to support it, so the leg first needs to be strong.
It is also really important to understand that your upper body strength comes primarily from your core muscles; a certain level of fitness is required in order to engage this core and correctly support yourself. If that doesn’t come naturally to you, doing some off-horse exercises may be necessary.
Having a strong and secure upper body also means that you are going to have independent hands and arms. In order to achieve this, we have our riders do several key, repetitive exercises. I encourage riders to practice holding one seat – a half or full seat – for extended periods of time. Maintaining one position and developing the feel for using hands and arms independently through transitions, which also eventually develops the ability to keep your body still, really creates the technique necessary to have a strong position.