The Effects of Probiotic Supplementation on Markers of Muscle Damage and Performance Following Exercise Induced Muscle Damage
Condition: Probiotics
Study type: Interventional
Phase: Phase 2

Summary: 
      To determine the effect of probiotic supplementation on the inflammatory response and
      subsequent performance following a muscle damaging exercise bout, a double-blind, randomized
      placebo controlled two-factor repeated measures design will be employed. The dependent
      variables for this study will include measures of performance as well as markers of
      inflammation in a single limb model. Participants who qualify for study participation will
      have their height, weight, and body composition assessed (skin fold) followed by baseline
      measurements for determination of isometric and dynamic strength. Initial limb will be
      determined randomly. Following baseline testing, participants will randomly be assigned to
      ingest either a probiotic or placebo. Supplementation will begin at least 24 hours post
      baseline testing. Twenty-one days after initiating supplementation, participants will again
      complete performance testing followed by an exercise bout known to elicit muscle damage and
      produce an inflammatory response. Participants will then repeat performance testing 24, 48,
      and 72 hours post muscle damaging bout. Blood samples for determination of markers of
      inflammation will be taken throughout study duration. Following a 3-week wash-out period (21
      days), participants will repeat the experiment following the alternate supplement regimen
      with the contralateral limb.
    

Detailed description: 
      General Performance Testing and Muscle Damaging Exercise Bout Following familiarization and
      consenting procedures, participants will complete a series of performance tests designed to
      determine maximal performance. Those tests will include a test of isometric strength and
      dynamic strength of the elbow flexors. Isometric strength will be tested with subjects elbow
      at a fixed angle and measurement of the force the subject exerts, while dynamic strength with
      be a test of maximal strength through a specified range of motion. Prior to baseline testing,
      participants will be asked to refrain from any physical activity outside of daily living for
      the preceding 48 hours as well as eliminate products that contain caffeine and/or alcohol.
      These tests will be repeated over the course of the study as outlined in Table 1 to examine
      if supplementation with probiotics attenuates the loss in strength following the muscle
      damaging exercise bout. An exercise bout known to induce significant muscle damage
      (eccentric) of the elbow flexors will be performed on Day 22 of supplementation. This will be
      an eccentric based protocol in which the muscle is stretched while generating force to
      overcome the stretch. To avoid any carryover effect, the initial arm will be selected at
      random while the contralateral arm will be used during the crossover experimental trial.

      Nutrition and Supplementation Following baseline performance measures, participants will be
      randomly assigned to ingest, in a double blind manner, either a probiotic supplement or
      placebo. Participants will begin supplementation 24 hours post baseline performance measures
      and will ingest the supplement (capsule form) once per day prior to consuming any food.
      Supplementation will continue for 25 days (21 days prior to post measures and 4 days of post
      testing). To ensure compliance, participants will report to the laboratory weekly and be
      provided individually wrapped supplement containers. Return of empty containers will be used
      to verify compliance. In addition, participants will complete a daily supplement adherence
      and adverse side effects questionnaire (Appendix) weekly upon reporting to the laboratory.

      Blood Sampling and Inflammatory Markers A baseline blood sample will be obtained prior to any
      performance testing and supplementation. Further, on the day of the muscle damaging exercise
      bout, participants will provide a blood sample for baseline determination of inflammatory
      blood markers and muscle damage. Blood samples will also be taken immediately post, 30, and
      60 minutes post damaging exercise bout. Participants will then return to the laboratory 24,
      48, and 72 hours following exercise bout to provide additional blood samples. Thirty six
      milliliters will be sampled at each time blood is drawn. If an emergency were to arise, the
      laboratory protocol for emergency management will be followed.

      Soreness and Swelling Assessment An algometer will assess deep muscle pain and trigger point
      tenderness of the biceps muscles resulting from muscle damage. The investigators will apply a
      pressure algometer at points on the muscle. The pressure threshold measurements will consist
      of the following steps. First, the following explanation will be given to each participant:
      'I am going to measure pressure threshold; that is, how much pressure will induce discomfort.
      I am going to increase pressure slowly with this device. Say ''Yes'' when you start to feel
      pain or discomfort. I will stop the pressure as soon as you say ''Yes'', so it will not hurt
      you. It is important that you understand that this is a test of sensitivity, not a test of
      endurance. Do you understand or have any questions?' After the explanation is given, the
      algometer will be placed exactly over the indelible mark and perpendicular to the muscle
      under observation. Pressure will increase continuously at 1 kg per second until the
      participant says 'Yes'. At this time, the pressure will stop, the meter removed from the
      skin, and the measurement recorded. The mean of 1 measurement taken at each of the 3 sites
      will be recorded as the pressure pain threshold. The subjects will be blinded to their
      pressure pain measurements. Additionally, the resting angle of the arm will be measured along
      with arm circumference to determine degree of swelling.
    

Intervention name(s): Lactic acid bacteria and bifidobacteria; Placebo
Intervention type(s): Dietary Supplement; Other
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)