Factors Informing Training Load During the Transition From Club to National Football Teams

This study examined the relationship of precamp match exposure, travel demands, perceptual wellness, and musculoskeletal screening with ensuing training load (TL) during national-team (NT) duties for international footballers (soccer).

Match minutes and days since last match prior to NT arrival were collected for match exposure. Travel duration and time-zone difference were included as travel demands. Perceptual fatigue, soreness, sleep quality, and stress scores were collected via self-report questionnaire on arrival to NT. Musculoskeletal testing on day 1 of NT included knee to wall and hip internal and external rotation. Relative TL across the first 3 days of NT camp was measured via total distance, high-speed running distance, very high-speed running distance, and accelerations and decelerations per minute. Linear mixed models determined the influence of independent variables on respective TL metrics, with the player included as a random effect.

Total distance, high-speed running, very high-speed running, and decelerations per minute were all highest on day 3 (P < .001). Small relationships existed (R2 < .15) between decreased total distance per minute and increased soreness (P = .037), while decreased high-speed running per minute was associated with increased fatigue (P = .017). Small associations existed between decreased accelerations per minute, increased hip internal rotation (P < .001), fatigue (P = .033), and knee to wall (P = .016), while decreased decelerations per minute were associated with increased soreness (P = .001), knee to wall (P = .024), and days between recent match and arrival (P = .003).

Very small relationships existed between fatigue, soreness, musculoskeletal screening, and prior match exposure with TL. The larger influence of camp day suggests that deliberate periodization of training is a major factor for prescription on arrival into NT duties.