This study will employ a randomized crossover design. Study participants will be block
randomized to three trials (high and low dose hemp fibers bars or placebo) using
double-blinded, placebo-controlled procedures. The supplement bars will be coded by the
sponsor, with the double-blind code held until after all study samples have been
analyzed. Subjects will come to the lab for orientation/baseline testing, pre-and
post-supplementation blood sample collections (2 weeks supplementation with high and low
dose hemp fiber bar supplements or placebo), and three 2.25 h cycling sessions (thus 9
total lab visits).
A. Orientation (Visit #1). Subjects will report to the lab in an overnight fasted state.
Subjects will voluntarily sign IRB-approved consent forms and complete questionnaires
(delayed onset of muscle soreness or DOMS, Profile of Mood States or POMS). Demographic,
health, and training histories will be acquired with questionnaires. A blood sample will
be collected. Subjects will ingest a standardized sugar solution containing lactulose 5
g, 13C mannitol 100 mg, mannitol 1.9 g, and rhamnose 1 g in a total of 450 ml water (SS,
calculated osmolality 69 mosmol/kg). An increase in the post-exercise lactulose/13C
mannitol ratio (L/M) will be used as an indicator of increased gut permeability. All
urine excreted from 0-5 h post SS ingestion will be collected in a urine collection
container. Subjects will be urged to drink water after the first hour of the test to
ensure adequate urine output. The Boost beverage will be consumed at 7 kcal/kg 1.5 h post
SS ingestion (to simulate what occurs post-exercise). The urine collection container will
be placed in the refrigerator until they are returned to the lab the next day. The total
urine volume will be measured with four 50 ml aliquots frozen in a minus 80°C freezer
until analysis.
B. Baseline Testing/Pre-Supplementation (Visit #2). Subject will return urine collection
container to the HPL the day after Visit #1. Body composition will be measured with the
seca BIA and Bod Pod body composition analyzer (Life Measurement, Concord, CA). Study
participants will be tested for maximal aerobic capacity (VO2max) during a graded,
cycling test with continuous metabolic monitoring with the Cosmed CPET metabolic device
(Cosmed, Rome, Italy). A 2-week supply of high dose or low dose hemp fiber bars or
placebo bars will be given to the participants. Subjects will consume 2 bars per day, one
with the first meal in the morning and the second bar with the last meal of the day.
C. 2.25 h Cycling Session (Lab Visit #3): During the 3-day period prior to the 2.25-h
cycling session, subjects will taper exercise training and ingest a moderate-carbohydrate
diet using a food list restricting high fat foods, visible fats, and caffeine. Subjects
will record all food and beverage intake in a 3-day food record with macro- and
micro-nutrient intake calculated using the ESHA Food Processor nutrient analysis software
program. Study participants will report to the Human Performance Lab in an overnight
fasted state and provide a blood sample, ingest the supplement (1 hemp fiber bar or
placebo bar), and then cycle 2.25 h at high intensity (70% VO2max) while ingesting water
alone (3 ml/kg every 15 minutes). Immediately following the cycling bout, subjects will
ingest the SS. Blood samples will be collected at 0 h, 1.5 h, and 3.0 h post-exercise.
All urine excreted from 0-5 h after SS ingestion will be collected in a urine collection
container.
Testing protocol during the lab sessions with the 2.25-h cycling session:
7:00 am: Provide blood sample, DOMS rating (1-10 scale), and POMS. Complete the
symptom survey. Turn in the 3-day food record.
7:10 am: Ingest 1 supplement bar with 1 cup water.
7:30 am: Start the 2.25 h cycling session. Subjects will cycle on trainers at 70%
VO2max (~race pace) for 2.25 hours. Oxygen consumption, carbon dioxide production,
respiratory exchange ratio, and ventilation will be measured using the Cosmed Quark
CPET metabolic cart every 30 minutes. Subjects will consume 3 ml/kg water every 15
min. No other beverage or food containing energy or nutrients will be allowed during
the 2.25-h exercise sessions.
~10:00 am to 1:00 pm: Ingest the 450 mL SS within the first minute of getting off
the bicycle. All urine excreted from 0-5 h after SS ingestion will be collected in a
urine collection container. Blood samples will be taken via venipuncture immediately
after completing the cycling session, and then 1.5-h and 3.0-h post-exercise.
Subjects will be allowed to shower and change clothes. The DOMS and POMS
questionnaires will be administered each time blood samples are collected. Subjects
will ingest no food or beverage other than water (7 ml/kg during the 1.5 h
post-exercise period; this will take into account the 450 ml sugar solution; no
water will be ingested during the first hour post-SS intake). After the 1.5 h
post-exercise blood draw, subjects will ingest a Boost beverage (7 kcal/kg body
weight). Another blood sample will be collected 3-h post-exercise. Afterwards,
subjects will be allowed to stay in the lab to complete the 5h urine collection
(preferred procedure) or leave the lab and return later in the day to turn in the 5h
urine container. Upon request, subjects can also leave the lab, finish the 5h urine
collection, put the container in the refrigerator, and then bring the urine
container to the lab the next morning.
D. Washout/Crossover/Repeat
Subjects will engage in a 2-week washout period without the supplements, crossover to the
next treatment arm, and then repeat all procedures except for the consent process,
completion of the medical health questionnaire, body composition testing, and VO2 max
testing (Lab visits #4,5,6). Subjects will maintain the study diet and normal exercise
training routines during the 2-week washout period.
E. SECOND Washout/Crossover/Repeat
Subjects will engage in a 2-week washout period without the supplements, crossover to the
next treatment arm, and then repeat all procedures except for the consent process,
completion of the medical health questionnaire, body composition testing, and VO2 max
testing (Lab visits #7,8,9).