An addition curing silicone rubber composition and a cured product thereof are provided. The user support apparatus is interconnected to a frame of the exercise machine and includes at least one handhold interconnected to a user support. The magnitude of the net electrical charge in the body can be adjusted by input signals applied to the transistor, and the adjustment of the net electrical charge by the input signals can be at least partially cancelled by applying electrical voltage signals between the gate and the drain and between the source and the drain. Filter coefficients are adapted with a learning rule and filter weight update dynamics are stabilized to assist convergence to a stable separated ICA signal result. An error detector detects errors in the early decision output and generates a signal when the early decision output errors are detected.