Mind the "Gap": A Comparison of the Weekly Training Loads of English Premier League Academy Soccer Players in Under 23, Under 18 and Under 16 Age-Groups

Purpose The transition into full-time training represents a key period in the development of young soccer players. Here we compared the weekly training loads (matches, field-, and resistance-training) of English Premier-League Academy soccer players from under-16 (U16), under-18 (U18) and under-23 (U23) age-groups during a training meso-cycle. Methods Forty players (U16 n = 13, U18 n = 15 and U23 n = 12) were monitored using global navigation satellite systems and differential ratings of perceived exertion (dRPE). External load metrics were total distance, high-speed running distance, [absolute: >= 19.8 km/h, relative: >= 87% of 30-15 final-velocity (vIFT)], sprint distance (absolute: >= 25.2 km/h, relative: >= 80% maximal sprint speed), and dynamic stress load. Internal load metrics were dRPE training loads. Results Other than relative sprint distance, overall weekly external training loads were substantially greater for U18s and U23s when compared with U16s [effect size range: 1.09-1.99 (moderate to large); +/- 90% confidence limits similar to 0.45]. When compared with U16s, overall internal loads were substantially greater for U18s [0.69-0.95 (moderate); +/- similar to 0.40], but not U23s. Differences in weekly training loads between U18s and U23s were inconclusive. Conclusions Substantial differences in training loads between elite U16 players and their older counterparts, indicates the need for planned increases in training loads in anticipation of the transition into full-time training.