A method for monitoring a state of an article of footwear (100, 1500, 1600, 1700, 3400) comprising an intelligent system (106, 706, 1506) for sensing the conditions of use and for modifying a performance characteristic of the article of footwear (100, 1500, 1600, 1700, 3400) during use, the method comprising the steps of: measuring a sensor signal from a sensor (122, 722, 3650) at least partially disposed within a sole of the article of footwear (100, 1500, 1600, 1700, 3400); determining whether the article of footwear (100, 1500, 1600, 1700, 3400) has experienced a peak condition; upon determining that the article of footwear (100, 1500, 1600, 1700, 3400) has experienced a peak condition, determining whether adjustment of the article of footwear (100, 1500, 1600, 1700, 3400) is required; upon determining that adjustment is required, adjusting a performance characteristic of the article of footwear (100, 1500, 1600, 1700, 3400); monitoring a state of the article of footwear (100, 1500, 1600, 1700, 3400); determining if the article of footwear (100, 1500, 1600, 1700, 3400) has been inactive for a first time period; upon determining that the article of footwear (100, 1500, 1600, 1700, 3400) has been inactive for the first time period, enabling a semi-sleep mode in the intelligent system (106, 706, 1506), wherein in the semi-sleep mode the intelligent system (106, 706, 1506) is configured to power up for a brief period at regular intervals to check for activity from the sensor; determining if the article of footwear (100, 1500, 1600, 1700, 3400) has been inactive for a second time period; upon determining that the article of footwear (100, 1500, 1600, 1700, 3400) has been inactive for the second time period, enabling a deep-sleep mode in the intelligent system (106, 706, 1506), wherein in the deep-sleep mode only power to a single input mechanism need be maintained, so that the intelligent system (106, 706, 1506) can be turned on upon activation of that input mechanism; and reactivating the intelligent system (106, 706, 1506) upon an indication of use of the article of footwear (100, 1500, 1600, 1700, 3400), such as a vibration, a force, acceleration, velocity, and an increase in temperature within the shoe or a change in electric or other field strength within the shoe. measuring a sensor signal from a sensor (122, 722, 3650) at least partially disposed within a sole of the article of footwear (100, 1500, 1600, 1700, 3400); determining whether the article of footwear (100, 1500, 1600, 1700, 3400) has experienced a peak condition; upon determining that the article of footwear (100, 1500, 1600, 1700, 3400) has experienced a peak condition, determining whether adjustment of the article of footwear (100, 1500, 1600, 1700, 3400) is required; upon determining that adjustment is required, adjusting a performance characteristic of the article of footwear (100, 1500, 1600, 1700, 3400); monitoring a state of the article of footwear (100, 1500, 1600, 1700, 3400); determining if the article of footwear (100, 1500, 1600, 1700, 3400) has been inactive for a first time period; upon determining that the article of footwear (100, 1500, 1600, 1700, 3400) has been inactive for the first time period, enabling a semi-sleep mode in the intelligent system (106, 706, 1506), wherein in the semi-sleep mode the intelligent system (106, 706, 1506) is configured to power up for a brief period at regular intervals to check for activity from the sensor; determining if the article of footwear (100, 1500, 1600, 1700, 3400) has been inactive for a second time period; upon determining that the article of footwear (100, 1500, 1600, 1700, 3400) has been inactive for the second time period, enabling a deep-sleep mode in the intelligent system (106, 706, 1506), wherein in the deep-sleep mode only power to a single input mechanism need be maintained, so that the intelligent system (106, 706, 1506) can be turned on upon activation of that input mechanism; and reactivating the intelligent system (106, 706, 1506) upon an indication of use of the article of footwear (100, 1500, 1600, 1700, 3400), such as a vibration, a force, acceleration, velocity, and an increase in temperature within the shoe or a change in electric or other field strength within the shoe.