Recovery Kinetics After Speed-Εndurance Maintenance Training
Condition: Muscle Damage
Study type: Interventional

Summary: 
      The purpose of this study will be to inestigate the recovery kinetics on performance,
      neuromuscular fatigue and muscle microtaruma that will occur after two speed-endurance
      maintenance training protocols in elite male soccer players. Also, this study will determine
      the comparison between two different speed endurance maintenance protocols in neuromuscular
      fatigue, muscle microtrauma indicators and performance factors. The training protocols will
      be differentiated in training work to rest ratio. The firts training protocol trial will
      comprise the work to rest ratio (1:1) and the other trial will comprise the work to rest
      ratio 1:3.
    

Detailed description: 
      Speed endurance maintenance training is utilized in order to improve the repeated sprint and
      high speed running ability of soccer players during a soccer match. Also, speed endurance
      maintenance training includes soccer drills which stimulate high speed and powerful actions
      such as changes of directions, accelerations and decelerations. However these actions are
      associated with eccentric component and it is known that eccentric exercises induces muscle
      damage microtrauma. Thus, the aim of this study will be to investigate the recovery kinetics
      on performance, neuromuscular fatigue and muscle microtrauma that will occur after two
      speed-endurance maintenance training protocols in elite male soccer players. The speed
      endurance maintenance training (SEMT) sessions will be differentiated in training volume and
      specifically in the work to rest period. Specifically, a randomized three-trial, cross-over,
      repeated measures design will be applied. Elite male soccer players (aged 18-35 years) will
      participate in the present study. Also, it is considered necessary that the participants will
      not suffer from any musculoskeletal injuries that will limit their ability to perform the
      SEMT sessions. Also the participants will not be smokers and will not consume alcohol and
      ergogenic nutritional supplements before and during the study.

      In the first phase all participants will sign an informed consent form after they will be
      informed about all benefits and risks of this study and they will sign a recent historical of
      musculoskeletal injury or illness form. Subsequently, fasting blood samples will be collected
      by venipuncture using a disposable needle (10-gauge) in order to estimate muscle damage
      concentration markers (CK), blood lactate and inflammation markers (WBC). After, delayed
      onset muscle soreness (DOMS) in the knee flexors (KF) and extensors (KE) of both limbs, body
      weight (BW), height and body composition (DXA method) will be measured in the lab. Completing
      the first phase, participants will be instructed by a dietitian how to record a 7 days diet
      recalls estimating that the energy intake during the trials will be the same. The counter
      movement jump (CMJ) will be measured 24 hour after (second phase) on a force platform using
      two force platforms at 1000 Hz, with each foot in parallel on the two platforms providing a
      separate yet time-synchronized measurement of the data for each leg. During the CMJ will be
      measured the jump height (cm), the ground reaction force (N), the peak and mean power (W/kg),
      the vertical stiffness (Kvert, N/m/kg) and the peak rate of force development (RFD, N/s),
      while at the same time will be evaluated the change in peak and mean normalized EMG during
      the eccentric and concentric phases of the counter movement jump, for the vastus lateralis
      (VL), biceps femoris (BF), gastrocnemius (GAS), and gluteus maximus (GM) muscles.
      Electromyography data will be collected wirelessly at 2.000 Hz using a Myon MA-320 EMG
      system. The peak eccentric and concentric isokinetic torque of the knee flexors and
      extensors, in both limbs will be evaluated on an isokinetic dynamometer at 60°/sec. Also, the
      isometric peak torque of the knee extensors will be evaluated at 65o in both limbs. Also the
      fatigue rate during maximal voluntary isometric contraction will be estimated through the
      percent drop of peak torque between the first and the last three seconds of a 10-secong
      maximal isometric contraction. Also, the speed of 10m and 30m will be measured using light
      cells Chronojump system. The repeated sprint ability (RSA) (5x30m) will be measure using
      light cells Chronojump with 25 seconds rest in-between.

      The soccer agility drill with a ball will be measured using light cells Chronojump in order
      to evaluate the soccer technical skills, 24 hour after. Finally, Open-circuit spirometry will
      be utilized for assessment of maximal oxygen consumption (VO2max) using an automated online
      pulmonary gas exchange system via breath-by-breath analysis during a graded exercise testing
      on a treadmill. The ability to recover after repeated intense exercise will be evaluated
      through the YO-YO Intermittent Recovery test level 2 and YO-YO Intermittent Endurance test
      level 2. 96 hours after, the participants are going to perform one of the two speed endurance
      maintenance training session randomly in the field. The SEMT(1:1) session will include 1 set,
      6 repetitions per set and the work to rest ratio will be 1:1. The SEMT(1:3) session will
      iclude 1 set, 6 repetitions per set and the work to rest ratio will be 1:3. During the
      sessions will be assessed the change in Heart rate using a heart rate monitor and the field
      activity will be recorded using a global positiong system (GPS). The blood lactate will be
      evaluated immediately after each session. The DOMS indicator in the knee flexors (KF) and
      extensors (KE) of both limbs will be evaluated immediately after, 1h, 2h, 3h, 24h, 48h, and
      72 hours after each session. The isometric peak torque of the knee extensors will be
      evaluated at 65° in limbs, post and at 1h, 2h and 3h, hours after each session. Also the
      fatigue rate during maximal voluntary isometric contraction will be estimated through the
      percent drop of peak torque between the first and the last three seconds of a 10-secong
      maximal isometric contraction.

      Blood samples will be collected at 24h, 48h, and 72 hours after sessions. The counter
      movement jump (CMJ) will be measured immediately after the session, at 1h, 2h, 3h, at 24h,
      48h and 72 hours after session on a force platform using two force platforms at 1000 Hz, with
      each foot in parallel on the two platforms providing a separate yet time-synchronized
      measurement of the data for each leg. During the CMJ will be measured the jump height (cm),
      the ground reaction force (N), the peak and mean power (W/kg), the vertical stiffness (Kvert,
      N/m/kg) and the peak rate of force development (RFD, N/s), while at the same time will be
      evaluated the change in peak and mean normalized EMG during the eccentric and concentric
      phases of the counter movement jump, for the vastus lateralis (VL), biceps femoris (BF),
      gastrocnemius (GAS), and gluteus maximus (GM) muscles. Electromyography data will be
      collected wirelessly at 2.000 Hz using a Myon MA-320 EMG system. Also, the speed of 10m and
      30m will be measured using light cells Chronojump system immediately after, at 24h, 48h and
      72 hours after session. Finally the RSA test will be measured at 24h, 48h and 72 hours after
      sessions. Α 2 - week washout period will be adapted among trials. After, the participants
      will perform the process until they complete the trials.
    

Intervention name(s): SEMT(1:1); SEMT (1:3)
Intervention type(s): Other; Other
Intervention description(s): Soccer trainning protocolo will be performed on an work to rest ratio 1:1 and the trainning volume will consist of 1 set and 6 repetitions per set; Soccer trainning protocolo will be performed on an work to rest ratio 1:3 and the trainning volume will consist of 1 set and 6 repetitions per set
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Investigator)
Primary purpose: Other
Keywords: muscle damage; Eccentric exercise; Speed maintenance training; Soccer; Recovery