Is the difference between two methods of measuring soccer training load affected with different training themes?

Purpose: This study was to investigate whether the difference between measuring soccer training loads using the speed zone only method and metabolic power method was affected when the training sessions differ from aerobic endurance to speed strength (anaerobic). Due to the different physiological demands put on the participants brought about with different session themes, the effect on training load measurement was investigated. Methods: 18Hz vest worn GPS units were used to collect data from 22 participants participating in an aerobic endurance and a speed strength training themed sessions performed by a semi-professional soccer team. Results: Measuring the aerobic endurance session using metabolic power method had mean energy cost for the session of 1303.4  332.0 kJ whereas with the speed zone only method the result was that of 1242.5  289.5 kJ (Means  SD). Measuring the speed strength session using metabolic power method, the mean energy cost for the session was that of 1291.2  45.4 kJ whereas with the speed zone only method the result was that of 1268.3  43.6 kJ (Means  SD). The difference in energy cost for both sessions when calculated with both methods were not significant, p = 0.512 and p = 0.577 for the aerobic endurance and speed strength session respectively. Conclusions: In this study there was a difference between the two methods of measuring training loads in line with previous literature and also the aerobic endurance session had a mean of 3.1% higher difference between the two methods when compared with the difference between methods for the speed strength session. Although the difference in energy cost (kJ) calculation was affected when the session theme was changed, the difference was not statistically significant. Further studies with increased number of participants and participating teams should give a clearer answer.