A Menthol-Enhanced "Cooling" Energy Gel Does Not Influence Laboratory Time Trial Performance in Trained Runners.

l-menthol (menthol) is an organic compound derived from peppermint which imparts a refreshing mint flavor and aroma to oral hygiene products, chewing gum, and topical analgesics. Menthol has been identified as a non-thermal sensory cooling strategy for athletes when ingested or mouth-rinsed during exercise in hot environments. Therefore, sports nutrition products delivering a controlled concentration of menthol could be beneficial for athletes exercising in the heat. We sought to test the performance and perceptual outcomes of a novel menthol energy gel during treadmill running in the heat (33 °C, 49% RH). Fourteen trained runners (mean ± SD; age: 31 ± 6 years, VO2max: 56.5 ± 10.1 mL·kg-1·min-1, BMI: 23.2 ± 2.4 kg/m2; six female) participated in a randomized, crossover, double-blind, and placebo-controlled study. A menthol-enhanced energy gel (0.5% concentration; MEN) or flavor-matched placebo (PLA) was ingested 5 min before and again at 20 and 40 min of a 40 min treadmill exercise preload at 60% VO2max, followed by a 20 min self-paced time trial. The total distance, vertical distance, perceptual measures (thermal comfort, thermal sensation, rating of perceived exertion, and affect), and cognitive performance via computerized neurocognitive assessment were measured. No difference between 20 min self-paced time trial total distance (MEN: 4.22 ± 0.54 km, PLA: 4.22 ± 0.55 km, p = 0.867), vertical distance (MEN: 49.2 ± 24.6 m, PLA: 44.4 ± 11.4 m, p = 0.516), or any perceptual measures was observed (all p > 0.05). Cognitive performance was not different between the trials (all p > 0.05). These results suggest that a menthol energy gel is not superior to a non-menthol gel in terms of performance or perception during treadmill running in the heat. More research is needed to confirm whether these findings translate to ecologically valid settings, including outdoor exercise in ambient heat and during competition.

Athlete perceptions of flavored, menthol-enhanced energy gels ingested prior to endurance exercise in the heat.

Background: L-menthol evokes a cooling sensation by activating cold sensing cation channels. Menthol-enhanced fluids can be ergogenic during exercise in the heat by improving thermal perception; hence, the addition of menthol to energy gels may benefit athletes. Previously, unflavored menthol gels were deemed acceptable at 0.1% concentration, but no research has been undertaken on menthol gels with additional flavoring. Therefore, we determined athlete perceptions of flavored energy gels with different menthol concentrations. Methods: With a randomized, crossover, double-blind, placebo-controlled design, 27 athletes (34.8 ± 6.7 y, 9 females) ingested an energy gel with either 0.1%, 0.3%, 0.5%, or 0.7% menthol concentration, or a non-menthol, flavor-matched placebo (CON), on separate occasions before outdoor exercise. Gels were rated for cooling sensation, irritation, flavor, and overall experience on 100-point sensory and hedonic labeled magnitude scales. The duration of any cooling sensation was also reported. Results: All menthol gels delivered a greater cooling sensation compared to CON (7.4 ± 8.1 AU) with a significantly greater response for 0.7% (59.9 ± 20.5 AU) and 0.5% (57.7 ± 21.8 AU), compared to all others. Irritation was higher for all menthol gels compared to CON (3.4 ± 7.2 AU) and for 0.7% compared to 0.1% (31.1 ± 31.0 vs. 16.3 ± 21.0 AU, p = 0.041), with none rated above a 'mild-moderate' intensity. The menthol gels delivered a significantly longer cooling sensation duration (12.3-19.6 min) versus CON (2.2 ± 4.8 min) with no difference between menthol gels. Conclusion: A flavored menthol energy gel at 0.1-0.7% concentration provides a cooling sensation for athletes when ingested before exercise. The 0.5% concentration is recommended to maximize the cooling sensation whilst minimizing irritation.

Development of a "Cooling" Menthol Energy Gel for Endurance Athletes: Effect of Menthol Concentration on Acceptability and Preferences.

Menthol is effective at stimulating thermosensitive neurons that evoke pleasant cooling sensations. Internal application of menthol can be ergogenic for athletes, and hence, addition of menthol to sports nutrition products may be beneficial for athletes. The aim of this study was to develop a menthol energy gel for consumption during exercise and to determine acceptability and preferences for gels with different menthol concentrations. With a randomized, crossover, and double-blind placebo-controlled design, 40 endurance athletes (20 females) ingested an energy gel with a menthol additive at a high (0.5%; HIGH) or low concentration (0.1%; LOW), or a mint-flavored placebo (CON), on separate occasions during outdoor endurance training sessions. The athletes rated the gels for cooling sensation, mint flavor intensity, sweetness, and overall experience and provided feedback. Results are reported as median (interquartile range). Both menthol gels successfully delivered a cooling sensation, with a significantly greater response for HIGH (5.0 [4.0-5.0]) compared with LOW (3.5 [3.0-4.0]; p = .022) and CON (1.0 [1.0-2.0]; p < .0005), and LOW compared with CON (p < .0005). Ratings of mint flavor intensity followed the same trend as cooling sensation, while ratings of overall experience were significantly worse for HIGH (2.0 [1.0-3.0]) compared with LOW (4.0 [2.0-4.0]; p = .001) and CON (4.0 [3.0-4.0]; p < .0005). An energy gel with the addition of menthol at 0.1-0.5% provides a cooling sensation for athletes with a dose-response when ingested during exercise. The 0.1% concentration is recommended to maximize the overall experience of the gel.

The attention-enhancing effects of spearmint extract supplementation in healthy men and women: a randomized, double-blind, placebo-controlled, parallel trial.

Previous studies have demonstrated that chronic supplementation with a proprietary spearmint extract (PSE) can improve cognitive performance in individuals 50-70 years of age with age-related memory issues. In the present study, our hypothesis was that chronic supplementation of PSE would improve cognitive performance in young, active individuals. Using a randomized, double-blind, placebo-controlled, parallel design, healthy, recreationally active men and women (N = 142) received 900 mg of PSE or placebo (PLA) daily for 90 days. Cognition was assessed via cognitive test battery (CNS Vital Signs) that resulted in 10 cognitive domains. Sleep, mood, and quality of life were assessed via validated questionnaires. Measurements were evaluated on days 0, 7, 30, and 90 of supplementation. Significant (P < .05) treatment effects were observed for sustained attention, wherein PSE improved sustained attention vs PLA at day 30 (PSE: 33.3 ±â€¯0.54 vs PLA: 31.2 ±â€¯0.98; P = .001) and day 90 (PSE: 34.0 ±â€¯0.44 vs PLA: 32.7 ±â€¯0.75; P = .007). Significant (P < .05) treatment × visit interactions were observed for complex attention, wherein PSE improved complex attention compared to PLA at day 7 (PSE: 8.0 ±â€¯2.22 vs PLA: 7.6 ±â€¯0.57; P = .016). Significant (P < .05) improvements were observed in 2 individual tests: the shifting attention test and the 4-part continuous performance test. No significant differences were observed in mood, sleep, or quality of life. The current study demonstrates that chronic supplementation with 900 mg of PSE improves cognitive performance in a young, active population, further supporting PSE as an efficacious nootropic.

Efficacy of a nootropic spearmint extract on reactive agility: a randomized, double-blind, placebo-controlled, parallel trial.

BACKGROUND: Proprietary spearmint extract (PSE) containing a minimum 14.5% rosmarinic acid and 24% total phenolic content, has evinced positive effects on cognition in individuals aged 50-70 with memory impairment after chronic supplementation. To address the growing interest in connecting mental and physical performance, the present study examined whether the nootropic effects of PSE translate into changes in reactive agility following daily supplementation with PSE. METHODS: Utilizing a randomized, double-blind, placebo-controlled, parallel design, healthy, recreationally-active men and women (n = 142) received 900 mg of PSE or placebo (PLA) daily for 90 days. Reactive agility, our primary outcome, was determined by measuring the number of hits and average reaction time (ART) on a Makoto Arena II, a 3600 audio-visual device that measures stationary, lateral, and multi-directional active choice reaction performance. Safety was evaluated using complete blood count, comprehensive metabolic panel, and blood lipids. Measurements were evaluated on days 7, 30, and 90 of supplementation. RESULTS: An overall treatment effect (p = 0.019) was evident for increased hits with PSE on the stationary test with footplates, with between group differences at Day 30 (PSE vs. PLA: 28.96 ± 2.08 vs. 28.09 ± 1.92 hits; p = 0.040) and Day 90 (PSE vs. PLA: 28.42 ± 2.54 vs. 27.02 ± 3.55 hits; p = 0.002). On the same task, ART improved (treatment effect, p = 0.036) with PSE at Day 7 (PSE vs. PLA: 0.5896 ± 0.060 vs. 0.6141 ± 0.073 s; p = 0.049) and Day 30 (PSE vs. PLA: 0.5811 ± 0.068 vs. 0.6033 ± 0.055 s; p = 0.049). PSE also significantly increased hits (treatment effect, p = 0.020) at Day 30 (PSE vs. PLA: 19.25 ± 1.84 vs. 18.45 ± 1.48 hits; p = 0.007) and Day 90 (PSE vs. PLA: 19.39 ± 1.90 vs. 18.66 ± 1.64 hits; p = 0.026) for the multi-directional test with footplates. Significant differences were not observed in the remaining Makoto tests. PSE was well tolerated as evidenced by no effects observed in the blood safety panels. CONCLUSIONS: The findings of the current study demonstrate that consumption of 900 mg of PSE improved specific measures of reactive agility in a young, active population. TRIAL REGISTRATION: clinicaltrials.gov, NCT02518165 . Registered August 7, 2015 - retrospectively registered.

Daytime and nighttime casein supplements similarly increase muscle size and strength in response to resistance training earlier in the day: a preliminary investigation.

BACKGROUND: Casein protein consumed before sleep has been suggested to offer an overnight supply of exogenous amino acids for anabolic processes. The purpose of this study was to compare supplemental casein consumed earlier in the day (DayTime, DT) versus shortly before bed (NightTime, NT) on body composition, strength, and muscle hypertrophy in response to supervised resistance training. METHODS: Thirteen males participated in a 10-week exercise and dietary intervention while receiving 35 g casein daily. Isocaloric diets provided 1.8 g protein/kg body weight. RESULTS: Both groups increased (p < 0.05) in lean soft tissue (DT Pre: 58.3 ± 10.3 kg; DT Post: 61.1 ± 11.1 kg; NT Pre: 58.3 ± 8.6 kg; NT Post: 60.3 ± 8.2 kg), cross-sectional area (CSA, DT Pre: 3.4 ± 1.5 cm2; DT Post: 4.1 ± 1.7 cm2; NT Pre: 3.3 ± 1.6 cm2; NT Post: 3.7 ± 1.6 cm2) and strength in the leg press (DT Pre: 341 ± 87.3 kg; DT Post: 421.1 ± 94.0 kg; NT Pre: 450.0 ± 180.3 kg; NT Post: 533.9 ± 155.4 kg) and bench press (DT Pre: 89.0 ± 27.0 kg; DT Post: 101.0 ± 24.0 kg; NT Pre 100.8 ± 32.4 kg; NT Post: 109.1 ± 30.4 kg) with no difference between groups in any variable (p > 0.05). CONCLUSIONS: Both NT and DT protein consumption as part of a 24-h nutrition approach are effective for increasing strength and hypertrophy. The results support the strategy of achieving specific daily protein levels versus specific timing of protein ingestion for increasing muscle mass and performance. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03352583 .

Ancient peat and apple extracts supplementation may improve strength and power adaptations in resistance trained men.

BACKGROUND: Increased cellular ATP levels have the potential to enhance athletic performance. A proprietary blend of ancient peat and apple extracts has been supposed to increase ATP production. Therefore, the purpose of this investigation was to determine the effects of this supplement on athletic performance when used during 12 weeks of supervised, periodized resistance training. METHODS: Twenty-five healthy, resistance-trained, male subjects completed this study. Subjects supplemented once daily with either 1 serving (150 mg) of a proprietary blend of ancient peat and apple extract (TRT) or an equal-volume, visually-identical placebo (PLA) daily. Supervised resistance training consisted of 8 weeks of daily undulating periodized training followed by a 2 week overreach and a 2 week taper phase. Strength was determined using 1-repetition-maximum (1RM) testing in the barbell back squat, bench press (BP), and deadlift exercises. Peak power and peak velocity were determined during BP at 30 % 1RM and vertical jump tests as well as a 30s Wingate test, which also provided relative power (watt:mass) RESULTS: A group x time interaction was present for squat 1RM, deadlift 1RM, and vertical jump peak power and peak velocity. Squat and deadlift 1RM increased in TRT versus PLA from pre to post. Vertical jump peak velocity increased in TRT versus PLA from pre to week 10 as did vertical jump peak power, which also increased from pre to post. Wingate peak power and watt:mass tended to favor TRT. CONCLUSIONS: Supplementing with ancient peat and apple extract while participating in periodized resistance training may enhance performance adaptations. TRIAL REGISTRATION: ClinicalTrials.gov registration ID: NCT02819219 , retrospectively registered on 6/29/2016.

Twelve weeks supplementation with an extended-release caffeine and ATP-enhancing supplement may improve body composition without affecting hematology in resistance-trained men.

BACKGROUND: Increased ATP levels may enhance training-induced muscle accretion and fat loss, and caffeine is a known ergogenic aid. A novel supplement containing ancient peat and apple extracts has reported enhanced mitochondrial ATP production and it has been coupled with an extended-release caffeine. Therefore, the purpose of this investigation was to determine the effects of this supplement on body composition when used in conjunction with 12 weeks of resistance training. METHODS: Twenty-one resistance-trained subjects (27.2 ± 5.6y; 173.5 ± 5.7 cm; 82.8 ± 12.0 kg) completed this study. Subjects supplemented daily with either 1 serving of the supplement (TRT), which consisted of 150 mg ancient peat and apple extracts, 180 mg blend of caffeine anhydrous and pterostilbene-bound caffeine, and 38 mg B vitamins, or an equal-volume, visually-identical placebo (PLA) 45 min prior to training or at the same time of day on rest days. Supervised resistance training consisted of 8 weeks of daily undulating periodized training followed by a 2-week overreach and a 2-week taper phase. Body composition was assessed using DEXA and ultrasound at weeks 0, 4, 8, 10, and 12. Vital signs and blood markers were assessed at weeks 0, 8, and 12. RESULTS: Significant group x time (p < 0.05) interactions were present for cross-sectional area of the rectus femoris, which increased in TRT (+1.07 cm(2)) versus PLA (-0.08 cm(2)), as well as muscle thickness (TRT: +0.49 cm; PLA: +0.04 cm). A significant group x time (p < 0.05) interaction existed for creatinine (TRT: +0.00 mg/dL; PLA: +0.15 mg/dL) and estimated glomerular filtration rate (TRT: -0.70 mL/min/1.73; PLA: -14.6 mL/min/1.73), which remained within clinical ranges, but no other significant observations were observed. CONCLUSIONS: Supplementation with a combination of extended-release caffeine and ancient peat and apple extracts may enhance resistance training-induced skeletal muscle hypertrophy without adversely affecting blood chemistry.

Supplementation with a proprietary blend of ancient peat and apple extract may improve body composition without affecting hematology in resistance-trained men.

Adenosine-5'-triphosphate (ATP) is primarily known as a cellular source of energy. Increased ATP levels may have the potential to enhance body composition. A novel, proprietary blend of ancient peat and apple extracts has been reported to increase ATP levels, potentially by enhancing mitochondrial ATP production. Therefore, the purpose of this investigation was to determine the supplement's effects on body composition when consumed during 12 weeks of resistance training. Twenty-five healthy, resistance-trained, male subjects (age, 27.7 ± 4.8 years; height, 176.0 ± 6.5 cm; body mass, 83.2 ± 12.1 kg) completed this study. Subjects supplemented once daily with either 1 serving (150 mg) of a proprietary blend of ancient peat and apple extracts (TRT) or placebo (PLA). Supervised resistance training consisted of 8 weeks of daily undulating periodized training followed by a 2-week overreach and a 2-week taper phase. Body composition was assessed using dual-energy X-ray absorptiometry and ultrasound at weeks 0, 4, 8, 10, and 12. Vital signs and blood markers were assessed at weeks 0, 8, and 12. Significant group × time (p < 0.05) interactions were present for ultrasound-determined cross-sectional area, which increased in TRT (+0.91 cm(2)) versus PLA (-0.08 cm(2)), as well as muscle thickness (TRT: +0.46; PLA: +0.04 cm). A significant group × time (p < 0.05) interaction existed for creatinine (TRT: +0.06; PLA: +0.15 mg/dL), triglycerides (TRT: +24.1; PLA: -20.2 mg/dL), and very-low-density lipoprotein (TRT: +4.9; PLA: -3.9 mg/dL), which remained within clinical ranges. Supplementation with a proprietary blend of ancient peat and apple extracts may enhance resistance training-induced skeletal muscle hypertrophy without affecting fat mass or blood chemistry in healthy males.

Consuming a multi-ingredient thermogenic supplement for 28 days is apparently safe in healthy adults.

BACKGROUND: Thermogenic (TRM) supplements are often used by people seeking to decrease body weight. Many TRM supplements are formulated with multiple ingredients purported to increase energy expenditure and maximize fat loss. However, in the past some TRM ingredients have been deemed unsafe and removed from the market. Therefore, it is important to verify the safety of multi-ingredient TRM supplements with chronic consumption. OBJECTIVE: To assess the safety of daily consumption of a multi-ingredient TRM supplement over a 28-day period in healthy adults. DESIGN: Twenty-three recreationally active adults (11M, 12F; 27.1±5.4 years, 171.6±9.6 cm, 76.8±16.1 kg, 26±5 BMI) were randomly assigned either to consume a multi-ingredient TRM supplement (SUP; n=9) or remain unsupplemented (CRL; n=14) for 28 days. Participants maintained their habitual dietary and exercise routines for the duration of the study. Fasting blood samples, resting blood pressure, and heart rate were taken before and after the supplementation period. Samples were analyzed for complete blood counts, comprehensive metabolic, and lipid panels. RESULTS: Significant (p<0.05) group by time interactions were present for diastolic BP, creatinine, estimated glomerular filtration rate (eGFR), chloride, CO2, globulin, albumin:globulin (A/G), and high-density lipoprotein (HDL). Dependent t-tests conducted on significant variables revealed significant (p<0.05) within-group differences in SUP for diastolic BP (+6.2±5.3 mmHG), creatinine (+0.09±0.05 mg/dL), eGFR (-11.2±5.8 mL/min/1.73), globulin (-0.29±0.24 g/dL), A/G (+0.27±0.23), and HDL (-5.0±5.5 mg/dL), and in CRL for CO2 (-1.9±1.5 mmol/L) between time points. Each variable remained within the accepted physiological range. CONCLUSION: Results of the present study support the clinical safety of a multi-ingredient TRM containing caffeine, green tea extract, and cayenne powder. Although there were statistically significant (p<0.05) intragroup differences in SUP from pre- to postsupplementation for diastolic BP, creatinine, eGFR, globulin, A/G, and HDL, all remained within accepted physiological ranges and were not clinically significant. In sum, it appears as though daily supplementation with a multi-ingredient TRM is safe for consumption by healthy adults for a 28-day period.

A multi-ingredient, pre-workout supplement is apparently safe in healthy males and females.

BACKGROUND: Pre-workout supplements (PWS) have become increasingly popular with recreational and competitive athletes. While many ingredients used in PWS have had their safety assessed, the interactions when combined are less understood. OBJECTIVE: The purpose of this study was to examine the safety of 1 and 2 servings of a PWS. DESIGN: Forty-four males and females (24.4±4.6 years; 174.7±9.3 cm; 78.9±18.6 kg) from two laboratories participated in this study. Subjects were randomly assigned to consume either one serving (G1; n=14) or two servings (G2; n=18) of PWS or serve as an unsupplemented control (CRL; n=12). Blood draws for safety panels were conducted by a trained phlebotomist before and after the supplementation period. RESULTS: Pooled data from both laboratories revealed significant group×time interactions (p<0.05) for mean corpuscular hemoglobin (MCH; CRL: 30.9±0.8-31.0±0.9 pg; G1: 30.7±1.1-30.2±0.7 pg; G2: 30.9±1.2-30.9±1.1 pg), MCH concentration (CRL: 34.0±0.9-34.4±0.7 g/dL; G1: 34.1±0.9-33.8±0.6 g/dL; G2: 34.0±1.0-33.8±0.8 g/dL), platelets (CRL: 261.9±45.7-255.2±41.2×10(3)/µL; G1: 223.8±47.7-238.7±49.6×10(3)/µL; G2: 239.1±28.3-230.8±34.5×10(3)/µL), serum glucose (CRL: 84.1±5.2-83.3±5.8 mg/dL; G1: 86.5±7.9-89.7±5.6 mg/dL; G2: 87.4±7.2-89.9±6.6 mg/dL), sodium (CRL: 137.0±2.7-136.4±2.4 mmol/L; 139.6±1.4-140.0±2.2 mmol/L; G2: 139.0±2.2-138.7±1.7 mmol/L), albumin (CRL: 4.4±0.15-4.4±0.22 g/dL; G1: 4.5±0.19-4.5±0.13 g/dL; G2: 4.6±0.28-4.3±0.13 g/dL), and albumin:globulin (CRL: 1.8±0.30-1.8±0.28; G1: 1.9±0.30-2.0±0.31; G2: 1.8±0.34-1.8±0.34). Each of these variables remained within the clinical reference ranges. CONCLUSIONS: The PWS appears to be safe for heart, liver, and kidney function in both one-serving and two-serving doses when consumed daily for 28 days. Despite the changes observed for select variables, no variable reached clinical significance.

Subcutaneous and segmental fat loss with and without supportive supplements in conjunction with a low-calorie high protein diet in healthy women.

BACKGROUND: Weight loss benefits of multi-ingredient supplements in conjunction with a low-calorie, high-protein diet in young women are unknown. Therefore, the purpose of this study was to investigate the effects of a three-week low-calorie diet with and without supplementation on body composition. METHODS: Thirty-seven recreationally-trained women (n = 37; age = 27.1 ± 4.2; height = 165.1 ± 6.4; weight = 68.5 ± 10.1; BMI = 25.1 ± 3.4) completed one of the following three-week interventions: no change in diet (CON); a high-protein, low-calorie diet supplemented with a thermogenic, conjugated linoleic acid (CLA), a protein gel, and a multi-vitamin (SUP); or the high-protein diet with isocaloric placebo supplements (PLA). Before and after the three-week intervention, body weight, %Fat via dual X-ray absorptiometry (DXA), segmental fat mass via DXA, %Fat via skinfolds, and skinfold thicknesses at seven sites were measured. RESULTS: SUP and PLA significantly decreased body weight (SUP: PRE, 70.47 ± 8.01 kg to POST, 67.51 ± 8.10 kg; PLA: PRE, 67.88 ± 12.28 kg vs. POST, 66.38 ± 11.94 kg; p ≤ 0.05) with a greater (p ≤ 0.05) decrease in SUP than PLA or CON. SUP and PLA significantly decreased %Fat according to DXA (SUP: PRE, 34.98 ± 7.05% to POST, 32.99 ± 6.89%; PLA: PRE, 34.22 ± 6.36% vs. POST, 32.69 ± 5.84%; p ≤ 0.05), whereas only SUP significantly decreased %Fat according to skinfolds (SUP: PRE, 27.40 ± 4.09% to POST, 24.08 ± 4.31%; p ≤ 0.05). SUP significantly (p ≤ 0.05) decreased thicknesses at five skinfolds (chest, waist, hip, subscapular, and tricep) compared to PLA, but not at two skinfolds (axilla and thigh). CONCLUSIONS: The addition of a thermogenic, CLA, protein, and a multi-vitamin to a three-week low-calorie diet improved weight loss, total fat loss and subcutaneous fat loss, compared to diet alone.

Safety of a dose-escalated pre-workout supplement in recreationally active females.

BACKGROUND: Pre-workout supplements (PWS) have increased in popularity among athletic populations for their purported ergogenic benefits. Most PWS contain a "proprietary blend" of several ingredients, such as caffeine, beta-alanine, and nitrate in undisclosed dosages. Currently, little research exists on the safety and potential side effects of chronic consumption of PWS, and even less so involving female populations. Therefore, the purpose of the present study was to examine the safety of consuming a dose-escalated PWS over a 28-day period among active adult females. METHODS: 34 recreationally active, adult females (27.1 ± 5.4 years, 165.2 ± 5.7 cm, 68.2 ± 16.0 kg) participated in this study. Participants were randomly assigned to consume either 1 (G1) or 2 (G2) servings of a PWS daily or remain unsupplemented (CRL) for a period of 28 days. All were instructed to maintain their habitual dietary and exercise routines for the duration of the study. Fasting blood samples, as well as resting blood pressure and heart rate, were taken prior to and following the supplementation period. Samples were analyzed for hematological and clinical chemistry panels, including lipids. RESULTS: Significant (p < 0.05) group by time interactions were present for absolute monocytes (CRL -0.10 ± 0.10; G1 + 0.03 ± 0.13; G2 + 0.01 ± 0.12×10E3/uL), MCH (CRL -0.13 ± 0.46; G1 + 0.36 ± 0.52; G2 -0.19 ± 0.39 pg), creatinine (CRL 0.00 ± 0.05; G1 -0.06 ± 0.13; G2 -0.14 ± 0.08 mg/dL), eGFR (CRL -0.69 ± 5.97; G1 + 6.10 ± 15.89; G2 + 14.63 ± 7.11 mL/min/1.73), and total cholesterol (CRL -2.44 ± 13.63; G1 + 14.40 ± 27.32; G2 -10.38 ± 15.39 mg/dL). Each of these variables remained within the accepted physiological range. No other variables had significant interactions. CONCLUSION: The present study confirms the hypothesis that a PWS containing caffeine, beta-alanine, and nitrate will not cause abnormal changes in hematological markers or resting vital signs among adult females. Although there were statistically significant (p < 0.05) group by time interactions for absolute monocytes, MCH, creatinine, eGFR, and total cholesterol, all of the results remained well within accepted physiological ranges and were not clinically significant. In sum, it appears as though daily supplementation with up to 2 servings of the PWS under investigation, over an interval of 28 days, did not adversely affect markers of clinical safety among active adult females.

28 days of creatine nitrate supplementation is apparently safe in healthy individuals.

BACKGROUND: Creatine monohydrate has become a very popular nutritional supplement for its ergogenic effects. The safety of creatine monohydrate has previously been confirmed. However with each novel form of creatine that emerges, its safety must be verified. Therefore, the purpose of this study was to examine the safety of a novel form of creatine, creatine nitrate (CN), over a 28 day period. METHODS: 58 young males and females (Pooled: 24.3 ± 3.9 years, 144.9 ± 8.0 cm, 74.2 ± 13.0 kg) participated in this study across two laboratories. Subjects were equally and randomly assigned to consume either 1 g (n = 18) or 2 g (n = 20) of CN or remained unsupplemented (n = 20). Blood draws for full safety panels were conducted by a trained phlebotomist prior to and at the conclusion of the supplementation period. RESULTS: Pooled data from both laboratories revealed significant group x time interactions for absolute lymphocytes and absolute monocytes (p < 0.05). Analysis of the 1 g treatment revealed lab x time differences for red blood cell distribution width, platelets, absolute monocytes, creatinine, blood urea nitrogen (BUN):creatinine, sodium, protein, and alanine aminotransferase (ALT) (p < 0.05). Analysis of the 2 g treatment revealed lab x time differences for BUN:creatinine and ALT (p < 0.05). BUN and BUN:creatinine increased beyond the clinical reference range for the 2 g treatment of Lab 2, but BUN did not reach statistical significance. CONCLUSION: Overall, CN appears to be safe in both 1 g and 2 g servings daily for up to a 28 day period. While those with previously elevated BUN levels may see additional increases resulting in post-supplementation values slightly beyond normal physiological range, these results have minor clinical significance and are not cause for concern. Otherwise, all hematological safety markers remained within normal range, suggesting that CN supplementation has no adverse effects in daily doses up to 2 g over 28 days and may be an alternative to creatine monohydrate supplementation.