Analysis of Internal Training Load Variation Over Ten Microcycles of the Preparatory and Competitive Periods in a European Youth Football Team

Abstract

The current study compared weekly internal training load across 10 microcycles (M) in under-12 athletes. Twenty-eight under-12 soccer players (age, 10.96 ± 0.19 years; height, 152.82 ± 7.47 cm; weight, 40.76 ± 6.29 kg) participated in the study. Internal training load was quantified using session Rating of Perceived Exertion. The average weekly load, accumulated weekly load, monotony and training strain were calculated for each M (1 to 5 of the preparatory period and 6 to 10 of the competitive period). Results revealed significant differences considering all metrics (all, p < .001). Specifically, the average weekly load was lower in M4 and M7, while the accumulated weekly load was lower in M1, M2 and M9. Training monotony and training strain showed lower values (all, p < .001) in M1 and M9 (0 arbitrary units) and the highest on M6. The data revealed load variations with all metrics analysed. However, the main differences were found between the microcycles with the lowest number of training sessions (one or two) and the remaining microcycles, which reveals a general maintenance of the load throughout the preparatory and competitive periods. However, this appears to be the first study carried out with under-12 athletes, providing relevant data for coaches and their technical staff.