U-SAFT⁹⁰ simulates the internal and external loads of university-level soccer match play

Guard, Andrew

Abstract

Motion analysis has become more prevalent in contemporary soccer research, particularly within the elite sector. The study of motion-profiles can be used for identifying patterns in soccer match performance regarding both physical and technical elements. Deducing movement patterns and internal and external loading through in-depth study, it may then be possible to simulate competitive match-play specific to squad or individual needs. Modern technology allows match performance to be broken down into specific periods that subsequently enables the examination of work rate. Changes in work-rate may indicate fluctuations in performance which can also heighten the risk of injury and susceptibility to conceding to opponents. As a result, preparatory, conditioning and nutritional interventions can be employed directed towards sustaining performance levels.

This thesis will firstly look at motion profiles of competitive soccer in an amateur population in order to quantify the internal and external physical demands and variation in work-rate compared to those previously scrutinised in elite soccer. The following experimental chapter utilises motion analysis data to create and validate a squad soccer-specific exercise protocol (SSEP) to use as a simulation of soccer match-play in both rehabilitation and laboratory settings.

Motion analysis was determined with a 5Hz Global Positioning System to analyse total, high-intensity and sprint distance as well as producing mechanical ‘Accumulated Player Load’ values through an in-built accelerometer. This data was combined with concurrent heart rate data during matches to provide a measure of internal physiological load. Total distance was found to range between 7223-12158m, with an average of 9423m for the squad, declining 6% between halves (P < 0.01) with a coefficient of variation of 12% between matches. High-intensity distance was 1593m on average, declining 14% between halves (P < 0.01), with a 24.9% between-match variation. The average peak HID covered in a 5 minute period was 142m, with the subsequent period 46% lower (76m), 18% lower than the match 5 minute mean (P < 0.05). The final 5 minute period in a match averaged 66m at high-intensity. Mean sprint distance was 137m, varying 44% between matches. Heart rate was 164bpm-1 on average (86%HRmax) while Accumulated Player Load was 994AU on average. The motion analysis found similar patterns of physical demands (in terms of fluctuations in intensity) to those found in elite studies, although total, high-intensity and sprint distances were not as high in university players.

The second study sought to simulate the internal and external loads of competitive amateur soccer match in a controlled environment by developing a population-specific laboratory simulation, University Soccer Aerobic Field Test⁹⁰. The test comprised of a 15 minute CD repeated 6 times to produce a 90 minute simulation of a competitive match. The CD gave audio commands to the subjects completing the USAFT⁹⁰ course of multilateral soccer-specific movements. The CD was created by using average velocities from discreet movement categories, together with the average distances covered in each zone, using the data from the first study. Validation of USAFT⁹⁰ was done by monitoring the same internal and external load measures in the same population for both motion analysis and laboratory simulation. Using the same population meant greater ecological validity of the subsequent findings. The USAFT⁹⁰ showed a degree of cardiovascular strain through measurement of heart rate for internal physiological load, averaging 162 bpm-1 (85% HRmax). The external load measured by accelerometer ‘accumulated player load’ was 1067 AU on average. Statistical comparisons of heart rate and accumulated player load between competitive match-play and USAFT⁹⁰ showed no significant differences in the internal and external loading (P > 0.05).

The findings in this thesis suggest patterns of physical demands in competitive amateur match play are similar to those of elite soccer, in terms of total, high-intensity and sprint distances but fall in the lower part of the range previously reported in motion-analysis studies. Changes in work-rate possibly due to fatigue are evident in motion profiles of amateur soccer players, similar to those observed in professionals. Furthermore heart rate analysis suggested cardiovascular strain is also high.

Competitive amateur match-play can be simulated effectively with respect to inducing the same internal and external loads associated with a 90 minute soccer match. The implications of such findings are that the USAFT⁹⁰ can be used to simulate the locomotor, physiological and mechanical demands of amateur soccer matches in controlled environments. This may be useful for rehabilitation purposes and testing intervention strategies to gauge effect on performance. Future research should address positional differences and examine the effect of fatigue on work-rate in more detail for university-level soccer. This would accommodate individual and positional capabilities that were not simulated in USAFT⁹⁰.

Citation

Guard, A. (2012). U-SAFT⁹⁰ simulates the internal and external loads of university-level soccer match play. (Thesis). University of Hull. Retrieved from https://hull-repository.worktribe.com/output/4213623

• Thesis Type: Thesis
• Deposit Date: Jan 15, 2013
• Publicly Available Date: Feb 22, 2023
• Keywords: Sport science
• Public URL: https://hull-repository.worktribe.com/output/4213623
• Additional Information: Department of Sport, Health and Exercise Science, The University of Hull
• Award Date: Jan 1, 2012