The Effects of Probiotic Supplementation on Markers of Muscle Damage and Performance Following Exercise Induced Muscle Damage



Status:Recruiting
Healthy:No
Age Range:18 - 35
Updated:4/21/2016
Start Date:February 2015

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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.

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.

Inclusion Criteria:

- Participants must currently be participating in structured resistance training and
must have been doing so for the previous 1 year period.

Exclusion Criteria:

- Having consumed any nutritional supplements and/or ergogenic aids for the preceding 6
week period.

- Having not taken any anti-inflammatory medications for the previous month.
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Fort Worth, Texas 76129
Phone: 817-257-5623
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