title: Two Weeks of Repeated-Sprint Training in Soccer: To Turn or Not to Turn?
abstract: OBJECTIVE
  To compare the effects of 2 repeated-sprint training programs on fitness in soccer.
  
  
  METHODS
  Fifteen semiprofessional soccer players (age: 24 ± 4 y; body mass: 77 ± 8 kg) completed 6 repeated-sprint training sessions over a 2-week period. Players were assigned to a straight-line (STR) (n = 8; 3-4 sets of 7 × 30 m) or change of direction (CoD) (n = 7; 3-4 sets of 7 × 20-m) repeated-sprint training group. Performance measures included 5-, 10-, and 20-m sprints, countermovement jump, Illinois agility, and Yo-Yo Intermittent Recovery Test level 1 (YYIRTL1) performance. Internal (heart rate) and external (global positioning system-derived measures) training loads were monitored throughout. Data were analyzed using magnitude-based inferences.
  
  
  RESULTS
  Internal and external loads were higher in the STR group than in the CoD group with large differences in maximum velocity (28.7%; ±90% confidence limits, 3.3%), moderate differences in mean heart rates (7.0%; ±1.4%) and PlayerLoad (17.6%; ±8.6%), and small differences in peak heart rates (3.0%; ±1.6%). Large improvements in 5-m (STR: 9.6%; ±7.0% and CoD: 9.4%; ±3.3%), 10-m (STR: 6.6%; ±4.6% and CoD: 6.7%; ±2.2%), and 20-m (STR: 3.6; ±4.0% and CoD: 4.0; ±1.7%) sprints were observed. Large and moderate improvements in YYIRTL1 performance were observed in the STR (24.0%; ±9.3%) and CoD (31.0%; ±7.5%), respectively. Between-groups differences in outcome measures were unclear.
  
  
  CONCLUSIONS
  Two weeks of repeated-sprint training stimulates improvements in acceleration, speed, and high-intensity running performance in soccer players. Despite STR inducing higher internal and external training loads, training adaptations were unclear between training modes, indicating a need for further research.
authors: Jonathan M
authors: JM
authors: Taylor
authors: Tom W
authors: TW
authors: Macpherson
authors: Shaun J
authors: SJ
authors: McLaren
authors: Iain
authors: I
authors: Spears
authors: Matthew
authors: M
authors: Weston
mesh_terms: D000054:Acceleration; D000222:Adaptation, Physiological; D000328:Adult; D054874:Athletic Performance; D001696:Biomechanical Phenomena; D040362:Geographic Information Systems; D006339:Heart Rate; D000072696:High-Intensity Interval Training / Q000379:methods*; D006801:Humans; D008297:Male; D053580:Muscle Strength; D064797:Physical Conditioning, Human / Q000379:methods*; D010807:Physical Endurance; D011597:Psychomotor Performance; D012420:Running; D012916:Soccer; D013997:Time Factors; D013996:Time and Motion Studies; D055815:Young Adult
keywords: HIT; shuttle sprinting; soccer training; training load