the effects of tyrosol and creatine on endurance, strength, and fatigue resistance in healthy adults

Conditions: Tyrosol; Creatine; Endurance Performance; Cognition

Summary: the purpose of this clinical trial is to look at tyrosol's effects on endurance, strength, and fatigue resistance in humans. additionally, the combination of tyrosol and creatine monohydrate will also be looked at to determine if there is a cooperative effect from using both together. it will be conducted over a 4-week period to compare the effects of the following substances: 1) tyrosol, 2) a placebo (a look-alike substance that contains no drug), 3) creatine, and 4) a combination containing both creatine and tyrosol. endurance, strength, and fatigue resistance will be compared between groups through repeated testing (described below). participants who pass initial screening will be invited on-site for day one (visit 1) of testing where they will proceed with a series of tests which will include the following: (1) body composition; (2) cognitive testing; (3) full-body strength testing; (4) grip strength on both hands; (5) muscle power testing; (6 \& 7) resting blood lactic acid testing followed by 5rm (repetition maximum) bench press, leading to multiple sets of bench press (based on the previous weight) completed to failure, followed by another blood lactic acid reading; (8) a repeat of the muscle power testing; (9) a 1 mile time trial run completed as fast as possible. after the 4-week supplementation period (\~28-34 days), all original measures will be repeated as before in the same order (visit 2). approximately 24 hours later (visit 3) participants will then repeat all physical testing procedures except tests 1, 6, 7, and 8, to determine physical recovery. additionally, questionnaires for soreness and perceived recovery will also be completed at the beginning of visit 2 and 3, and again on its own as the only testing event at 48 hours post-visit 2 (visit 4).

this study will be a randomized, double-blind, placebo-controlled trial. it will be conducted over a 4-week intervention investigating the effects of tyrosol (500mg tyrosol); placebo control (3g resistant dextrin), and two additional groups including creatine alone (3g creatine monohydrate) and a combination group containing both creatine and tyrosol (3g creatine monohydrate + 500mg tyrosol/day). endurance, strength, and fatigue resistance will be examined through repeated strength and endurance testing as described below. on day one (visit 1) of testing, after a minimum 8-hour overnight fast, subjects will proceed with a series of tests in the following successive order: (1) dxa for body composition followed by consumption of a standardized food bar snack and at least a 15-minute break after the snack. after the 15-minute break, subjects will proceed with the following tests: (2) psychomotor vigilance test (pvt); (3) full-body strength measurement using a computerized mid-thigh pull; (4) strength via grip strength on both hands, tested in triplicate using a dynamometer; (5) 2 sets of 2 plyometric push-ups (with the average of each set used as the outcome metric) on a dual ground-reaction force plate, with a 30 seconds rest between sets; (6 \& 7) resting blood lactate will be measured in duplicate followed by determination of the subject's 5rm (repetition maximum) bench press, which will be used to calculate their 1rm. subjects will then perform one set of bench at 70% of the calculated 1rm to failure, followed by three sets to failure at 50 % of 1rm with a two-minute rest between all sets. after completion of the last set, another blood lactate reading will be taken (in duplicate) and recorded; (8) subjects will then perform the plyometric push-up protocol one more time to assess the immediate effects of fatigue; (9) subjects will then complete a 1 mile time trial run completed as fast as possible. rate of perceived exertion (rpe) will also be collected during the 1 mile run using borg rpe scale (borg, 1982).vo2 max will be estimated from the 1 mile run time, age, gender and bmi, using equations described by kayihan et al. (2014). finally, the subjects will repeat the pvt at the end of the session. after the 4 week supplementation period (approximately 28+6 days), all baseline measures will be repeated in the fasted state, in the same successive order (visit 2). approximately 24 hours later (visit 3) subjects will then repeat all physical testing procedures except tests 1, 6, 7, and 8 (which would exclude dxa, blood lactate, bench press 5rm and sets to failure, and the second plyometric push-up test) to assess physical recovery between groups. additionally, likert scales for soreness and perceived recovery will be completed as the first outcome measure just prior to the first pvt exam, at visit 2 and 3, and again on its own as the only testing event performed at 48 hours post-bout (visit 4). finally, on post-testing days (visit 2 and 3), a full dosage of the study treatment will be taken with water, as well as a standardized food bar snack; and will be administered on-site by staff. on visit 2, this supplement will be taken just after completion of the dxa (prior to likert and pvt); on visit 3, the treatment will be taken prior to the start of likert scales and pvt testing. the subjects will wait for at least 15 minutes after the snack and treatment to begin the remaining tests.

Eligibility criteria:
inclusion criteria: * healthy males or females aged 18-50 * currently active (engaged in moderate to vigorous activity at least 2-days per week as defined by the american college of sports medicine guidelines) * estimated vo2 max equal to or greater than the 50th percentile of the population norm for age (assessed via acsm guidelines, 2014). the vo2 max estimation at screening will be obtained by following a non-exercise regression model validated and described by bradshaw et al. (2005). * able to read and write in english * during the study, agree not to take any other supplements that may increase muscle strength or endurance (e.g. protein formulas, creatine, amino acids, tyrosol or stimulants other than caffeine). * females willing to share days menstrual cycle for testing purposes as shifts in hormone levels may, potentially, affect testing exclusion criteria: * known diagnosis of any cardiovascular, metabolic, endocrine, or renal disease * recent musculoskeletal injury (\<3-months) * recent orthopaedic surgery (\<12-months) * history or current malignancy * previous gastrointestinal surgery within the past 12 months * regular smoker * regular drinker (\>14 drinks per week) * current use (within the past 4 weeks) of creatine supplements * current use (within past 3 months) of tyrosol supplementation * current use of dietary supplements that may enhance mitochondrial function, muscle hypertrophy, or muscle strength (e.g. protein formulas, creatine, amino acids, tyrosol, etc.). * current use of prescription medications that may influence adaptation to exercise (hormone therapies, peptides, etc.) * female subjects who do not test negative on a urine pregnancy test or are lactating.

Keywords: tyrosol creatine muscle strength muscle endurance muscle recovery muscle performance reaction time