The lump on the back of rugby shirts is a visible part of a sophisticated biometric tracking system used by coaches to track a variety of statistics about every player. The padded casing surrounds a unit that is commonly referred to as a GPS tracker, although it contains other measuring devices. The visible part is the packaging designed to protect both the electronics and the player from damage due to the usual impacts in rugby. The tracking unit can be carried in a specially made pocket on the back of the shirt or in a harness worn under the shirt. The GPS sensor measures a host of different physical data points, including distance covered, speeds reached, and heart rate. This data can be used to manage a players workload to make sure that they stay healthy and able to perform at their peak for the entire season.