Conventional flexible pressure sensors are not suitable for high-pressure applications due to their low saturation pressure. In this study, an ultra-wide range pressure sensor is designed based on the optimized microstructure of the polyimide/carbon nanotubes (PI/CNT) nanocomposite film. The sensing range of the pressure sensor is expanded by adopting polyimide (PI) with a high elastic modulus as a matrix material and its sensitivity is improved through functional sensing film with tip-flattened microdome arrays. As a result, the pressure sensor can measure a wide pressure range (approximate to 0-3000 kPa) and possesses the sensitivity of approximate to 5.66 x 10(-3)-0.23 x 10(-3) kPa(-1) with high reliability and durability up to 1000 cycles. The proposed sensor is integrated into the hand and foot pressure monitoring systems for workout monitoring. The representative values of the pressure distribution in the hands and feet during the powerlifting are acquired and analyzed through Pearson's correlation coefficient (PCC). The analyzed results suggest that the pressure sensor can provide useful real-time information for healthcare and sports performance monitoring.