A method of measuring physical workload for a task is provided. Afterreceiving task execution data, an exerted energy value is calculated inresponse to the received task execution data. A physical performance indexvalue is then generated based the exerted energy value. The exerted energyvalue can be calculated based on a calculated work value, which itself isbased on the received task execution data. A physical performace device, suchan exercise machine, can be characterized based on the performance indexvalue. The method can include compling a physical performance device profileincluding the physical performance index value, and optionally transmittingthe profile to a storage means. The method can also include identifiying afunctional muscle group associated with the device. The measured physicalworkload can be a measured value of user performance, which can be compared toa target value to determine a user's physical performance.
