Limitations of current electronic textiles (e-textiles), including poor washability, instability, and inferior sensing capability, are concerns hindering their broad and practical applications in personal health care management, virtual games, sports, and more. Here, we report an RGO/PANI e-textile via alternative coatings of in situ reduced graphene oxides (RGO) and in situ polymerized polyaniline (PANI), establishing a laminated structure on a knitted textile substrate. As a result of an in situ lamination strategy, our e-textile exhibits excellent breathability (1428 mm s-1, greater than that of bare cotton fabric) and outstanding sensitivity (gage factor of 39.7) over a wide strain range (~ 0.0625–200%). Importantly, we observed exceptional sensing durability even after severe mechanical disturbance of stretching, bending, or twisting (> 1500 cycles) and daily machine washes. Detailed analysis revealed that our proposed in situ lamination approach enabled the physical and chemical interactions between sensing active materials and the textile substrate. Furthermore, the electromechanical behavior of our RGO/PANI e-textile was thoroughly analyzed based on an equivalent electrical circuit, which agreed well with the experimental data. Example applications of the e-textile were demonstrated for personal health care management, including body motion monitoring, emotional sensing, and flatfoot gait correction. The RGO/PANI e-textile presented in this study holds significant implications for the evolution of health care applications utilizing smart e-textiles.