Analysis of Overtime in Soccer
Condition: Metabolic Stress
Study type: Interventional

Summary: 
      A randomized, two-trial (placebo vs. supplement consumption), cross-over, double-blind,
      repeated measures design will be applied to study i) the performance, metabolic and
      inflammatory overload of overtime in soccer and ii) how carbohydrate supplementation affects
      recovery following a football match with overtime. The study will be performed during a brake
      of the in-season period to mimic a real life setting. A 10-day washout period will be
      utilized between trials.
    

Detailed description: 
      Initially and before the familiarization period, measurement of descriptive variables will be
      performed: body composition, maximal oxygen consumption, football-specific endurance via
      YO-YO IE2 and IR2, technical performance, daily diet intake, resting metabolic rate (canopy
      method), and daily physical activity (IPAQ questionnaire). At this time, volunteers (of equal
      technical, tactical and physical potential) will be randomly assigned (equally representing
      all field positions) to two teams.

      A 7-day familiarization period will be applied initially during which participants will be
      accustomed with research procedures, match tactics, and diet (a standard diet will be given
      based on their dietary analysis, RMR measurement and daily energy expenditure). During this
      adaptive period, volunteers will participated in light training aimed at developing team
      cohesion.

      Thereafter, the two experimental trials will take place. Each trial will include
      administration of either a high carbohydrate diet (CHO trial) or standard diet (control
      trial) and they will be carried out in a random order for each participant. Each trial will
      included two 120-min matches (M1 and M2) performed 3 days apart according to UEFA official
      schedules for National teams' tournaments. On match days, volunteers will participate only in
      morning testing sessions but not practice. Prior to each game, a standard breakfast and meal
      will be consumed. During each match, players will be allowed to drink only water ad libitum
      and their water intake will be recorded. Sweat loss during the match will be determined by
      measuring players' body mass wearing dry shorts immediately before the match, at half time,
      immediately after the match and immediately after each half of the overtime. Two practice
      sessions will take place on days 1 and 2 between M1 and M2 designed according to the training
      model routinely adapted by national football teams during the UEFA EURO tournament. Matches
      will be organized according to official UEFA regulations. Field activity during matches and
      practices will be recorded using high time-resolution GPS instrumentation and heart rate
      monitoring. Following M1 and for the next 3 days until M2, participants will receive either
      carbohydrate or placebo. Diet intake will be monitored daily throughout the study.

      Performance assessments will be performed post-matches and daily between matches.

      Blood samples will be collected at baseline as well as at 90 and 120 min of each match and
      before M2.

      Muscle biopsies will be collected at baseline as well as at 90 and 120 min of M1 and before
      M2.
    

Intervention name(s): Control Diet; Experimental Diet
Intervention type(s): Other; Other
Intervention description(s): Players during the control trial will be instructed to maintain their normal food intake (~55% CHO) and the type and amount of ingested food will be recorded.; The experimental diet will be administered by the investigators after M1, daily for the next 48 hours (three main meals, i.e. breakfast, lunch, and dinner, and snacks such as energy bars and raisins), and before M2 (breakfast and lunch)
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Basic Science
Keywords: soccer; overtime; performance; recovery