The aim of the thesis is to develop an individualised approach to monitoring training load monitoring and prescription of training in order to effectively develop soccer fitness. The first investigation focused upon quantifying athlete locomotion, and the consequent speed thresholds applied. Considering that high-speed activities typically occur during the most important parts of competition, it is extremely important that these are quantified accurately. It was found that for athletes with high maximum running capabilities, high-speed locomotion distances were similar when utilising either the global or individualised speed thresholds. However for athletes with moderate or low maximum running capabilities, high-speed locomotion distances were significantly underestimated when using global speed thresholds in comparison to individual. These results suggest the use of a global analysis method for analysing athlete locomotion data is not an appropriate tool, and instead, the individual analysis method should be utilised. Following on from the initial investigation, focus shifted to identifying differences in physical demands elicited by soccer competition upon different playing position. Results showed significant differences between playing positions for a number GPS performance metrics. This suggests that each playing position not only has a specific technical and tactical role associated, but also a specific physical demand. Therefore increasing the rationale for a more individualised approach to soccer training. The final half of the thesis aims to address the gaps in the literature surrounding soccer training. Having identified the physical demands placed upon different playing positions, the following investigations are aimed at identifying which training methodologies (specifically small-sided games) are most appropriate for each playing position.