These

aspects of training are also referred to as the external training load. The training outcome is a consequence of this external training load and the associated level of physiological stress that it imposes on any given individual player (which is referred to as the internal training load).25 It is particularly important to assess internal training load as it is this component of physical training that actually produces the stimulus for adaptations.25 and 28 In soccer, as the external training load placed on players tends to be similar due to the use of group training sessions, it is important to monitor the internal training load as this will vary for any individual player.29 This would suggest that it is important to quantify both the external and internal training load in order to assess

the relationship between them30 and fully evaluate the training process. There are a variety MK 1775 of different methods that can be used to quantify both the internal and external training load in soccer.31 Internal training load measures such as HR assess the cardiovascular stress imposed on players.32 and 33 The validity of HR has been established through substantial research.34 and 35 New technologies such as global positioning systems (GPS) are now frequently used concomitantly with HR to provide a more detailed assessment of the training load placed on players.36 and 37 GPSs provide a better understanding of the individual training load placed upon the players by enabling detailed data to be collected, such as distance covered and the speed

at which these distance are covered.38 The accuracy of data that Hormones antagonist can be collected is dependent on the sampling frequency (5–15 Hz) for both GPS and accelerometer data (∼100 Hz). Considerable research has confirmed the validity of GPS monitoring in soccer training.36 and 39 Other approaches that can be used to evaluate training load are not reliant on expensive technical equipment. The use of subjective scales to evaluate the individual perception of training intensity such as the rating of perceived exertion (RPE) proposed by Foster Histone demethylase et al.40 have been widely used in soccer. These subjective approaches have been validated against various internal and external training load measures26 and 37 and it has been suggested that these approaches can lead to valid data collation. Data obtained through the monitoring of training can be used to enhance training content and subsequently improve performance. This improvement is partly dependent on the effective analysis and feedback to coaches and players. Feedback is a vital part of the coaching process (Fig. 1). The methods in which feedback can be delivered can vary significantly and depend on the individual preferences of both coaches and/or players. Reports that include both graphical and/or numerical representations of data are examples of such methods. Reports can also include an analysis of individual exercises (e.g.