The Effect of Short-Term Interval Training during the Competitive Season on Physical Fitness and Signs of Fatigue: A Crossover Trial in High-Level Youth Football Players

• DOI: 10.1123/ijspp.2013-0429
• Publication Date: 2014-03-11T20:56:45Z
• Authors: Oliver Faude; Anke Steffen; Michael Kellmann; Tim Meyer
• Keywords: Crossover study; Interval training; Football players

To analyze performance and fatigue effects of small-sided games (SSG) vs high-intensity interval training (HIIT) performed during a 4-wk in-season period in high-level youth football.Nineteen players from 4 teams (16.5 [SD 0.8] y, 1.79 [0.06] m, 70.7 [5.6] kg) the 2 highest German divisions completed study. Teams were randomly assigned to 1 sequences (2 endurance sessions per wk): One group started with SSG, whereas other conducted HIIT first half competitive season. After winter break, programs changed between groups. Before after periods following tests completed: Recovery-Stress Questionnaire for Athletes, creatine kinase urea concentrations, vertical-jump height (countermovement jump [CMJ], drop jump), straight sprint, agility, an incremental field test determine individual anaerobic threshold (IAT).Significant time observed IAT (+1.3%, η(p)(2) = .31), peak heart rate (-1.8%, .45), CMJ (-2.3%, .27), no significant interaction groups (P > .30). Players low baseline values (+4.3%) showed greater improvements than those high initial (± 0.0%). A decrease was found total recovery (-5.0%, .29), increase concentration (+9.2%, .44).Four weeks can lead relevant capacity. The decreases total-recovery score together might be interpreted as early signs fatigue. Thus, danger overtaxing should considered.