Adaptive ultra-wideband wireless body area networks have been proposed as one of feasible mHealth platforms offering a high-speed, robust mobile health service. The error performance of such sytems outperforms non-adaptive systems by up to 4 dB. To further improve the error performance, the optimization of adaptive parameters is investigated in this paper. Simulation results show that the proposed optimal adaptive systems achieves a 2 dB gain with respect to bit error rate (BER). This improvement is equivalent to extra reduction of the power consumption up to 37% in these networks, thus increasing the longevity and reliability of mHealth services.