Abstract: An athletic monitoring device for attachment to a portion of an athlete'body or to athletic equipment. The device measures a predetermined parameter of the motion of the device while in use and compares the measured parameter to a predetermined range. Intensity of acceleration is measured by taking the square root of the sum of the squares of acceleration data for each of the three axes of motion. This value is compared to a threshold value. If greater than the threshold value, the square root value is stored and added to a second measured intensity value. In this manner, a sum of intensity values throughout a stroke is calculated. If the sum of intensities is above or below a predetermined range, appropriate signalling will so indicate.