Banana Cultivars and Exercise Performance and Recovery
Condition: Inflammation
MeSH terms: Inflammation
Study type: Interventional

Summary: 
      In a previous study at the Appalachian State University (ASU) Human Performance Laboratory at
      the North Carolina Research Campus (NCRC), investigators showed that cyclists ingesting about
      one-half of a banana with water every 15 minutes cycled 75-km faster (5%) than with water
      alone. The polyphenols (i.e., chemicals in plants with health benefits) in the banana
      improved the capacity to counter oxidative stress, and the sugars lowered post-exercise
      inflammation. The cyclists reported some gastrointestinal discomfort, however, from the high
      volume of bananas consumed. Dole Foods, the sponsor of this study, has a banana collection
      that includes many different varieties, including the Mini banana that has a higher sugar
      (50%) and phenolic (63%) content than the typical banana (Cavendish) available in stores.
      Thus athletes should experience similar performance benefits from a smaller volume of Mini
      compared to Cavendish bananas, and reduced gastrointestinal symptoms. If study results are
      favorable, Dole Foods may market the Mini banana as the "sport" banana.

      The purpose of this study is to compare ingestion of Mini and Cavendish bananas with an
      equicaloric, sugar-only beverage or water on 75-km cycling performance and post-exercise
      oxidative capacity and stress, inflammation, immune function, muscle damage and soreness, and
      gastrointestinal symptoms.
    

Detailed description: 
      The research procedures will be conducted at the Human Performance Laboratory (Room 1201,
      Plants for Human Health Institute Building, 600 Laureate Way), operated by Appalachian State
      University at the North Carolina Research Campus (NCRC) in Kannapolis, NC. Participants will
      come here for orientation/baseline testing and then 4 exercise test sessions (with each
      including two additional lab visits to provide 1- and 2-day 7:00 am recovery blood samples)
      (thus 13 total lab visits). The total amount of time participants will be asked to volunteer
      for this study is about 35 hours at the Human Performance Laboratory (over a 7 to 8-week
      period).

      ORIENTATION AND BASELINE TESTING:

      One to two weeks prior to the first 75-km cycling time trial, participants will report to the
      NCRC Human Performance Lab for orientation/baseline testing. 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.

      Participants will be tested for VO2max (i.e., maximal oxygen consumption) using the Lodi
      cycle ergometer. The purpose of the VO2max test is to determine maximum exercise capacity.
      The time commitment is about 30 to 60 minutes, and participants will wear exercise clothes
      and shoes that allow for free movement during vigorous exercise. Participants will be rested,
      well nourished, and hydrated for the test and avoid alcohol, caffeine, and tobacco 3 hours
      before the test. Participants will avoid significant exertion or exercise the day of testing
      and report any medication that are being used to the testing staff before the test. The test
      will begin with an exercise warm-up period of a few minutes, and then participants will pedal
      at progressively harder workloads. The test will continue until participants become fatigued
      and decide to stop, or other symptoms prohibit further exercise. Both leg tiredness and
      breathlessness are common sensations of the fatigue that participants may experience. During
      the test, participants will wear a facemask that allows exhaled air to be analyzed, and a
      chest strap for heart rate monitoring. Participants will communicate with the lab personnel
      during the test by the use of a perceived exertion chart to indicate how the exercise feels.

      Percent body fat will be measured using the BodPod. Participants will sit inside the BodPod
      with a tight-fitting swim suit for about 10 minutes while body fat is calculated.

      75-km CYCLING TIME TRIALS:

      A. 3-day pre-75 km cycling preparation: During the 3-day period prior to each 75-km cycling
      trial, participants will taper exercise training (as if preparing for a race) and ingest a
      moderate-carbohydrate diet using a food list restricting high fat foods and visible fats.
      Participants will record all food and beverage intake during the 3-day period, with nutrient
      intake assessed using a computerized dietary analysis software system. Participants will
      bring the food log to each exercise lab session.

      B. Testing procedures: Participants will come to the lab four times at 7:00 am in an
      overnight fasted state (at least 9 h with no food or beverage other than water) and complete
      75-cycling time trials (at least two weeks apart) under four separate conditions (random
      order, crossover): Water only (WAT); Cavendish bananas and water (BAN); Mini bananas and
      water (SPORT-BAN); 6% carbohydrate beverage (SUGAR).

        1. 7:00 am: A blood sample will be collected through a needle inserted into an arm vein
           (about 35 ml or 2.5 tablespoons). An ultrasound scan of the thigh muscle will be
           conducted to measure pre-exercise muscle glycogen levels. The side of the thigh will be
           scanned through a smooth probe attached to the General Electric LOGIQ-e ultrasound
           machine (GE Healthcare, Milwaukee, WI). Participants will lie on their backs with the
           skin over the thigh exposed. Three baseline scans will be obtained (each taking 10
           seconds), just prior to the exercise test, and then this muscle will be scanned three
           times again following the exercise bout. A simple questionnaire will be used for to
           indicate muscle soreness (DOMS). 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.). Participants will indicate responses using a
           12-point Likert scale, with 1 relating to "none at all", 6 "moderate", and 12 "very
           high".

        2. 7:10 am: Ingest 5 ml/kg water alone (about 1.5 cups), or SUGAR beverage, or water (5
           ml/kg) and BAN or SPORT-BAN (volume adjusted to provide 0.4 g carbohydrate per kilogram
           of body weight) (about two cups SUGAR beverage, one Cavendish banana, or 1.5 Mini
           bananas).

        3. 7:30 am: Start 75-km cycling time trial. Participants are to complete the 75-km course
           as fast as possible.

             -  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.

             -  Participants will consume 3 ml/kg water every 15 min (e.g., about one cup for a 75
                kg cyclist).

             -  Participants will ingest 0.2 g carbohydrate/kg body weight every 15 minutes of BAN,
                SPORT-BAN, or SUGAR beverage during the 75-km time trials. For a 75-kg cyclist,
                intake will be approximately 0.5 Cavendish banana, just under one Mini Banana, or
                one cup SUGAR beverage every 15 minutes. Bananas will be provided by Dole Foods at
                the appropriate ripening stage (equal to stage six). The SUGAR beverage will be
                prepared by Dole Foods, and will contain 60 grams sugar per liter using the same
                sugar profile found in Cavendish bananas.

             -  No other beverage or food containing energy or nutrients will be allowed during the
                cycling time trials.

        4. ~10:00-11:30 am: Immediate-post-exercise, 0.75-h, 1.5-h recovery blood samples; lunch

             -  Blood samples will be taken from an arm vein immediately after completing the 75-km
                time trial, and then 0.75-h and 1.5-h post-exercise. Participants will be allowed
                to shower and change clothes in the facility.

             -  An ultrasound scan for muscle glycogen levels will be conducted immediately
                post-exercise.

             -  Immediately post-exercise, participants will complete the symptom log.

             -  Participants will indicate muscle soreness using the DOMS questionnaire immediately
                post-exercise and 1.5-h post-exercise.

             -  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, 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.

        5. ~11:30 am to 2:30 pm: 3-h and 4.5-h recovery

             -  Additional blood samples will collected 3-h and 4.5-h post-exercise. During this
                time, participants will rest quietly in the lab.

             -  The DOMS questionnaire will be administered 4.5-h post-exercise.

             -  Participants will ingest no food or beverage other than water (7 ml/kg per hour).

             -  At ~2:30 pm, participants will be allowed to leave the lab, and will be instructed
                to adhere to the food list requirements, and to keep exercise training intensity
                moderate with duration under 1.5 h per day.

        6. 7:00 am: 21-h and 45-h Recovery samples (following two mornings) • 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.

      Blood samples will be analyzed for markers of muscle damage, inflammation and oxidative
      stress indicators (using blood levels and gene expression), and immune function. Stored
      samples will be measured for post-exercise shifts in hundreds of biochemicals using a special
      method called metabolomics, pending additional sponsor funding.
    

Intervention name(s): Water; Mini banana; Cavendish banana; 6% sugar beverage
Intervention type(s): Other; Other; Other; Other
Intervention description(s): Water only without carbohydrate; Ingest mini banana containing higher phenolics and carbohydrate concentration; Ingest Cavendish banana (common banana); Ingest 6% sugar beverage containing same glucose and fructose profile as banana
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: oxidative stress; immune function; muscle damage; carbohydrate; polyphenols; cycling