Method and calculations determine an individual's, or several individuals' simultaneous rates of oxygen consumption, maximum rates of oxygen consumption, heart rates, calorie expenditures, and METS (multiples of metabolic resting rate) in order to determine the amounts of work that is performed by the individual's body. A heart monitor measures the heart rate, and an accelerometer measures the acceleration of the body along one or more axes. An altimeter measures change in altitude, a glucose monitor measures glucose in tissue and blood, and thermometers, thermistors, or thermocouples measure body temperature. Data including body fat and blood pressure measurements are stored locally and transferred to a processor for calculation of the rate of physiological energy expenditure. Certain cardiovascular parameters are mathematically determined. Comparison of each axis response to the individual's moment can be used to identify the type of activity performed and the information may be used to accurately calculate total energy expenditure for each physical activity. Energy expenditure may be calculated by assigning a separate proportionality coefficient to each axis and tabulating the resulting filtered dynamic acceleration over time, or by comparison with previously predetermined expenditures for each activity type. A comparison of total energy expenditure from the current activity is compared with expenditure from a previous activity, or with a baseline expenditure rate to assess the level of current expenditure. A measure of the individual's cardio-vascular health may be obtained by monitoring the heart's responses to various types of activity and to total energy expended.