Abstract: Soccer match load is the sum of physical, physiological and psychological stimuli that a player bears in performing various actions in the match. The quantitative structure of match load is divided into external and internal load. The methods of quantifying external load include artificial video analysis technology, automatic trajectory tracking technology, and global positioning equipment. The load or intensity of a player’s physical strength or technical performance is used to evaluate the characteristics of his/her behavior and activity in soccer match. External load is mainly characterized by intermittent activities with changing directions and short distance running with changing velocity, and higher proportion of mid to low-intensity ball-free running combined lower proportion of high-intensity running with the ball. The methods of quantifying internal load include measurement of oxygen consumption, heart rate and blood lactic acid, and the changes in the above indicators are used to assess the energy metabolism level of players in soccer matches. Internal load is mainly characterized by aerobic energy supply together with alteration of anaerobic phosphate and glycolytic energy supply. The limitations of existing research are that the external load underestimates the impact of the changes of direction on the load of players in soccer match, and the internal load cannot summarize the energy supply characteristics in formal match. In the future, we can try to combine the internal and external load through optimizing quantization method to quantify the match load more accurately.

Key words: soccer, load quantization, intermittent, change of direction, energy consumption