The PURPOSE of this study is to investigate the combined influence of 2-weeks blueberry ingestion and banana ingestion (during exercise) on performance and in mitigating metabolic perturbation, immune dysfunction, and increase in inflammation following a 75-km cycling time trial. We hypothesize that the combination of 2-weeks ingestion of blueberries (versus placebo) and acute ingestion of bananas (versus water alone) during 75-km cycling will: 1. Enhance performance. 2. Attenuate the magnitude of metabolic perturbation due to exercise (using a targeted panel of metabolites) which may be associated with increased plasma levels of beneficial gut-derived phenolics. 3. Attenuate post-exercise inflammation (as measured with cytokines, muscle damage markers, regulatory lipid mediators, ex-vivo monocyte cell cultures, and targeted immune proteins including S100A8 and S100A12). 4. Counter post-exercise downturns in innate immune function (natural killer cell lytic activity), and viral defense (using an ex-vivo cell culture with Hela cells).
LAB VISIT #1: ORIENTATION AND BASELINE TESTING (about 1.5 hours): One to two weeks prior to the start of the study, study participants will report to the NCRC Human Performance Lab for orientation and baseline testing. Study participants will be screened to verify "low risk" status for cardiovascular disease, and provide voluntary consent. Demographic and training histories will be acquired with questionnaires. Study participants will be tested for VO2max (i.e., maximal oxygen consumption) using the Lodi cycle ergometer. Percent body fat will be measured using the BodPod. Study participants will sit inside the BodPod with a tight-fitting swim suit for about 10 minutes while body fat is calculated. LAB VISIT #2: START OF 2-WEEK SUPPLEMENTATION PERIOD (about 20 minutes) On the assigned date and time, study participants will return to the lab in an overnight fasted state (9 or more hours with no food or beverage including coffee and tea, other than water). A blood sample will be collected from an arm or hand vein by trained phlebotomists. Each blood sample will not exceed 35 ml (2.3 tablespoons), and will be analyzed for indicators of immune function, inflammation, muscle damage, stress hormones, and indicators of plant polyphenol metabolism. Study participants will be randomized to blueberry and placebo groups, and be given a 14-day supply of freeze-dried blueberry powder or placebo powder. The blueberry and placebo supplements will be ingested daily for 2-weeks prior to participation in the 75-km cycling time trial, the day of the exercise trial (after the blood draw, and supplied at the lab), and one day of recovery (after the blood draw, and supplied at the lab (thus 16 days total). The blueberry powder supplement (26 g per day or approximately one cup fresh blueberries equivalent) will consist of freeze-dried wild blueberries prepared by Future Ceuticals (Momence, IL). This product contains all of the polyphenols (in particular, anthocyanins), fiber, and natural sugars contained in fresh wild blueberries. The placebo powder will look identical but not contain freeze-dried blueberries. The placebo blueberry powder will consist of blueberry flavoring (2.8%), coloring (0.7% artificial purple, 0.3% artificial red), maltodextrin (21%), fructose (3.5%), citric acid (0.7%), and a silica flow agent (0.5%). Study participants will consume the blueberry and placebo powders by mixing them in fruit juices, yogurts, milk, or other products during the first meal of each day for two weeks. The blueberry and placebo powders should be stored in the freezer section of the refrigerator in the containers supplied to study participants. LAB VISIT #3: POST-SUPPLEMENTATION LAB VISIT WITH 75-km CYCLING (about 8-9 hours) * During the 3-day period prior to the 75-km cycling trial, study participants will taper exercise training and ingest a moderate-carbohydrate diet, with foods chosen from a food list moderating use of high fat foods, visible fats, and fruit/vegetable polyphenols. Study participants will record all food and beverage intake during the 3-day period. * After the 2-week supplementation period, study participants will return to the lab at 7:00 am in an overnight fasted and rested state (on the same day of the week and time as the pre-supplementation lab visit). * Study participants will turn in the 3-day food record. * Study participants will verify that they have ingested the assigned supplement each day. * A 35 ml blood sample will be collected. * Study participants will next ingest 26 g of freeze-dried blueberry powder or placebo powder in 1.5 cups of water (with Equal packets available to improve taste as desired). * A simple questionnaire will be used for study participants to indicate muscle soreness (DOMS). * Study participants will complete a symptom log, which will include questions on digestive and mental health (heartburn, bloating, diarrhea, nausea, energy levels, ability to focus, etc.). Study participants will indicate responses using a 12-point Likert scale, with 1 relating to "none at all", 6 "moderate", and 12 "very high". * Study participants will be randomized to cycle 75-km on water alone or with bananas and water (and this will be revealed after the blood draw). Twenty minutes after ingesting the supplement, study participants will start the 75-km cycling time trial. 75-km CYCLING TIME TRIAL 7:30 am: Start 75-km cycling time trial. Study participants are to complete the 75-km course as fast as possible. * Study participants will use their own bicycles on CompuTrainer Pro Model 8001 trainers (RacerMate, Seattle, WA). A mountainous 75-km course with moderate difficulty will be utilized using the CompuTrainer software system. * Heart rate and rating of perceived exertion (RPE) will be recorded every 30 minutes, and workload (watts) continuously monitored using the CompuTrainer MultiRider software system (version 3.0, RacerMate, Seattle, WA). * Oxygen consumption, carbon dioxide production, and ventilation will be measured using the Cosmed metabolic cart after 16 km and 55 km cycling (through a facemask similar to what occurred during baseline testing). Performance will be monitored throughout the 75-km cycling time trial using percentage of maximal watts to ensure that a full effort is being given. * Study participants will consume 3 ml/kg water every 15 min (e.g., about one cup for a 75 kg cyclist). * If randomized to ingest bananas with water: Study participants will ingest Cavendish bananas, with the volume adjusted to 0.2 g carbohydrate/kg body weight every 15 minutes (or 0.8 g/kg carbohydrate per hour) during the 75-km time trials. For a 75-kg cyclist, fruit intake will be approximately one-half banana every 15 minutes. Bananas will be provided by Dole Foods at the appropriate ripening stage (full yellow, stage six). No other beverage or food containing energy or nutrients will be allowed during the cycling time trials. \~10:00-11:30 am: Immediate-post-exercise, 1.5-h recovery blood samples; lunch * Blood samples will be taken from the arm vein immediately after completing the 75-km time trial, and then at 1.5-h post-exercise. * Immediately post-exercise, study participants will complete the symptom log. * Study participants will indicate muscle soreness using the DOMS questionnaire immediately post-exercise and 1.5-h post-exercise. * Study participants will ingest no food or beverage other than water (7 ml/kg or about two cups during the 1.5 h post-exercise period). * Right after the 1.5-h recovery blood sample has been collected, study participants will ingest a meal adjusted to 12 kcal/kg body weight. The meal will be prepared by Dole Foods and include grilled chicken, rice, corn, green beans, salt, and water. \~11:30 am to 3:00 pm: 3-h and 5-h recovery * Additional blood samples and DOMS responses will be collected 3-h and 5-h post-exercise. During this time, study participants will rest quietly in the lab. LAB VISITS #4 and #5: RECOVERY DAY BLOOD SAMPLES, 7:00 am: • Study participants will return to the lab the following two mornings in an overnight fasted state at about 7:00 am (\~21-h and 45-h after completing the 75-km time trial). Blood samples and responses to the DOMS questionnaire will be collected at both lab visits. Study participants will ingest the blueberry or placebo powder in the lab on the first recovery day following the blood sample collection.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
60
North Carolina Research Campus, Human Performance Lab
Kannapolis, North Carolina, United States
Inflammation
Cytokines
Time frame: Change from pre-supplementation to post-2-weeks supplementation, and to six post-exercise time points (0, 1.5, 3.0, 5.0, 21, 45 hours)
Metabolite shifts
Targeted panel of metabolites
Time frame: Change from pre-supplementation to post-2-weeks supplementation, and to six post-exercise time points (0, 1.5, 3.0, 5.0, 21, 45 hours)
Natural killer cell activity
Innate immune function
Time frame: Change from pre-supplementation to post-2-weeks supplementation, and to six post-exercise time points (0, 1.5, 3.0, 5.0, 21, 45 hours)
Exercise performance
75-km cycling time trial, with or without bananas
Time frame: After the 2-week period of blueberry or placebo intake
Targeted proteomics
Targeted panel of 24 immune proteins including S100A8 and S100A12
Time frame: Change from pre-supplementation to post-2-weeks supplementation, and to six post-exercise time points (0, 1.5, 3.0, 5.0, 21, 45 hours)
Muscle damage
Creatine kinase
Time frame: Change from pre-supplementation to post-2-weeks supplementation, and to six post-exercise time points (0, 1.5, 3.0, 5.0, 21, 45 hours)
Lipid mediators
Arachadonic acid oxidized derivatives from LC-MS-MS analysis
Time frame: Change from pre-supplementation to post-2-weeks supplementation, and to six post-exercise time points (0, 1.5, 3.0, 5.0, 21, 45 hours)
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