Acute Effects of Naturally Occurring Guayusa Tea and Nordic Lion's Mane Extracts on Cognitive Performance.

The aim of this study was to assess the effects of guayusa extract and Nordic Lion's Mane (LM) on cognition. Using a randomized, double-blind, placebo-controlled, crossover design, we examined the effects of a single dose of 650 mg guayusa extract (AMT: AmaTea® Max) vs. 1 g Nordic-grown Lion's Mane (LM) vs. placebo (PL). Participants attended three testing visits consisting of neuropsychological tests (Go/No-go, N-Back, and Serial 7 s tasks) assessing performance, subjective assessments of cognitive perception, and vital signs. Each assessment was measured at baseline (pre-ingestion) and 1 and 2 h post ingestion. AMT significantly (p ≤ 0.05) improved the number of attempts during Serial 7s, total score, number of correct responses, total number of responses, and reaction time during N-Back and improved Go stimulus reaction time, but it reduced the percentage of correct responses in the No-go stimulus response during Go/No-go. LM significantly (p ≤ 0.05) improved the number of attempts during Serial 7s and reaction time during N-Back and improved Go stimulus reaction time in Go/No-go. AMT improved mental clarity, focus, concentration, mood, and productivity at 1 and 2 h (p < 0.05); the ability to tolerate stress at 1 h; and had greater ratings than LM and PL for mental clarity, focus, concentration, and productivity. PL improved focus and concentration at 1 h from baseline (p ≤ 0.05). AMT and LM improved subjective ratings of "happiness compared to peers" and "getting the most out of everything" (p < 0.05); however, this occurred earlier in LM (i.e., 1 h post ingestion). AMT uniquely elevated blood pressure from baseline. AMT significantly improved cognitive performance and self-perceived cognitive indices of affect over a 2 h period and perceptions of happiness 2 h post ingestion. In comparison, LM helped improve working memory, complex attention, and reaction time 2 h post ingestion and perceptions of happiness over a 2 h period.

International society of sports nutrition position stand: coffee and sports performance.

Based on review and critical analysis of the literature regarding the contents and physiological effects of coffee related to physical and cognitive performance conducted by experts in the field and selected members of the International Society of Sports Nutrition (ISSN), the following conclusions represent the official Position of the Society:(1) Coffee is a complex matrix of hundreds of compounds. These are consumed with broad variability based upon serving size, bean type (e.g. common Arabica vs. Robusta), and brew method (water temperature, roasting method, grind size, time, and equipment).(2) Coffee's constituents, including but not limited to caffeine, have neuromuscular, antioxidant, endocrine, cognitive, and metabolic (e.g. glucose disposal and vasodilation) effects that impact exercise performance and recovery.(3) Coffee's physiologic effects are influenced by dose, timing, habituation to a small degree (to coffee or caffeine), nutrigenetics, and potentially by gut microbiota differences, sex, and training status.(4) Coffee and/or its components improve performance across a temporal range of activities from reaction time, through brief power exercises, and into the aerobic time frame in most but not all studies. These broad and varied effects have been demonstrated in men (mostly) and in women, with effects that can differ from caffeine ingestion, per se. More research is needed.(5) Optimal dosing and timing are approximately two to four cups (approximately 473-946 ml or 16-32 oz.) of typical hot-brewed or reconstituted instant coffee (depending on individual sensitivity and body size), providing a caffeine equivalent of 3-6 mg/kg (among other components such as chlorogenic acids at approximately 100-400 mg per cup) 60 min prior to exercise.(6) Coffee has a history of controversy regarding side effects but is generally considered safe and beneficial for healthy, exercising individuals in the dose range above.(7) Coffee can serve as a vehicle for other dietary supplements, and it can interact with nutrients in other foods.(8) A dearth of literature exists examining coffee-specific ergogenic and recovery effects, as well as variability in the operational definition of "coffee," making conclusions more challenging than when examining caffeine in its many other forms of delivery (capsules, energy drinks, "pre-workout" powders, gum, etc.).

Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show?

Supplementing with creatine is very popular amongst athletes and exercising individuals for improving muscle mass, performance and recovery. Accumulating evidence also suggests that creatine supplementation produces a variety of beneficial effects in older and patient populations. Furthermore, evidence-based research shows that creatine supplementation is relatively well tolerated, especially at recommended dosages (i.e. 3-5 g/day or 0.1 g/kg of body mass/day). Although there are over 500 peer-refereed publications involving creatine supplementation, it is somewhat surprising that questions regarding the efficacy and safety of creatine still remain. These include, but are not limited to: 1. Does creatine lead to water retention? 2. Is creatine an anabolic steroid? 3. Does creatine cause kidney damage/renal dysfunction? 4. Does creatine cause hair loss / baldness? 5. Does creatine lead to dehydration and muscle cramping? 6. Is creatine harmful for children and adolescents? 7. Does creatine increase fat mass? 8. Is a creatine 'loading-phase' required? 9. Is creatine beneficial for older adults? 10. Is creatine only useful for resistance / power type activities? 11. Is creatine only effective for males? 12. Are other forms of creatine similar or superior to monohydrate and is creatine stable in solutions/beverages? To answer these questions, an internationally renowned team of research experts was formed to perform an evidence-based scientific evaluation of the literature regarding creatine supplementation.

Effects of Hemp Extract on Markers of Wellness, Stress Resilience, Recovery and Clinical Biomarkers of Safety in Overweight, But Otherwise Healthy Subjects.

We determined the effects of a commercially available, GRAS (Generally Recognized As Safe) by independent conclusion, CBD-containing hemp oil extract on stress resilience, perceived recovery, mood, affect, body composition, and clinical safety markers in healthy human subjects.Methods: Using a randomized, placebo-controlled, double-blind design, 65 overweight, but otherwise healthy men and women (35.2 ± 11.4 years, 28.5 ± 3.3 kg/m2) ingested either Hemp Oil Extract [Hemp, 60 mg/d PlusCBDTM Extra Strength Hemp Extract Oil (15 mg hemp-derived CBD)] or a placebo (PLA) every day for six weeks while continuing to follow their normal diet and physical activity patterns. Outcome variables included changes in stress resilience, a 14-item panel of various psychometric parameters, heart-rate variability, plasma chromogranin A, body composition, and general markers of health. Data were analyzed using mixed factorial ANOVA, t-tests with 95% confidence intervals, and effect sizes (ES).Results: HDL cholesterol significantly improved in the Hemp group (p = 0.004; ES = 0.75). No other statistically significant group x time interaction effects were observed. Statistical tendencies for between-group differences were found for 'I Get Pleasure From Life' (p = 0.06, ES = 0.48) and 'Ability to Cope with Stress' (p = 0.07, ES = 0.46). Sleep quality (Hemp, p = 0.005, ES = 0.54) and sleep quantity (Hemp, p = 0.01, ES = 0.58) exhibited significant within-group changes. All values for hepato-renal function, cardiovascular health, fasting blood lipids, and whole blood cell counts remained within normal clinical limits with no between-group differences over time being identified.Conclusions: Hemp supplementation improved HDL cholesterol, tended to support psychometric measures of perceived sleep, stress response, and perceived life pleasure and was well tolerated with no clinically relevant safety concerns. Registered at clinicaltrials.gov: NCT04294706.

Effects of an Aqueous Extract of Withania somnifera on Strength Training Adaptations and Recovery: The STAR Trial.

Withania somnifera (Ashwagandha) is an Ayurvedic herb categorized as having "rasayana" (rejuvenator), longevity, and revitalizing properties. Sensoril® is a standardized aqueous extract of the roots and leaves of Withania somnifera. Purpose: To examine the impact of Sensoril® supplementation on strength training adaptations. Methods: Recreationally active men (26.5 ± 6.4 years, 181 ± 6.8 cm, 86.9 ± 12.5 kg, 24.5 ± 6.6% fat) were randomized in a double-blind fashion to placebo (PLA, n = 19) or 500 mg/d Sensoril® (S500, n = 19). Body composition (DEXA), muscular strength, power, and endurance, 7.5 km cycling time trial, and clinical blood chemistries were measured at baseline and after 12 weeks of supplementation and training. Subjects were required to maintain their normal dietary habits and to follow a specific, progressive overload resistance-training program (4-day/week, upper body/lower body split). 2 × 2 mixed factorial ANOVA was used for analysis and statistical significance was set a priori at p ≤ 0.05. Results: Gains in 1-RM squat (S500: +19.1 ± 13.0 kg vs. PLA +10.0 ± 6.2 kg, p = 0.009) and bench press (S500: +12.8 ± 8.2 kg vs. PLA: +8.0 ± 6.0 kg, p = 0.048) were significantly greater in S500. Changes in DEXA-derived android/gynoid ratio (S500: +0.0 ± 0.14 vs. PLA: +0.09 ± 0.1, p = 0.03) also favored S500. No other between-group differences were found for body composition, visual analog scales for recovery and affect, or systemic hemodynamics, however, only the S500 group experienced statistically significant improvements in average squat power, peak bench press power, 7.5 km time trial performance, and perceived recovery scores. Clinical chemistry analysis indicated a slight polycythemia effect in PLA, with no other statistical or clinically relevant changes being noted. Conclusions: A 500 mg dose of an aqueous extract of Ashwagandha improves upper and lower-body strength, supports a favorable distribution of body mass, and was well tolerated clinically in recreationally active men over a 12-week resistance training and supplementation period.

The Combined Effects of Exercise, Diet, and a Multi-Ingredient Dietary Supplement on Body Composition and Adipokine Changes in Overweight Adults.

BACKGROUND: Very few weight and fat loss supplements undergo finished-product research to examine efficacy. The purpose of this study was to determine the effects of an 8-week diet and exercise program on body composition, hip and waist girth, and adipokines and evaluate whether a dietary supplement containing raspberry ketone, capsaicin, caffeine, garlic, and Citrus aurantium enhanced outcomes. METHODS: Overweight men and women completed this randomized, placebo-controlled, double-blind study. Participants consumed 4 capsules/d of supplement (EXP; n = 18) or placebo (PLA; n = 18). Participants underwent 8 weeks of daily supplementation, calorie restriction (500 kcal < RMR [resting metabolic rate] × 1.2), and supervised progressive exercise training 3 times a week. Body composition, girth, and adipokines were assessed at baseline and postintervention (T1 and T2). RESULTS: Significant decreases in weight (-2.6 ± 0.57 kg, p < 0.001), fat mass (-1.8 ± 0.20 kg; p < 0.001), and percentage body fat (-3.7% ± 0.29%, p < 0.001) and a significant increase in lean body mass (LBM; 1.5 ± 0.26 kg; p < 0.001) were seen from T1 to T2 in both groups. For men, only those in the EXP group increased LBM from T1 to T2 (1.3 ± 0.38 kg; p < 0.05). Hip girth was also reduced, with the women in the EXP group (-10.7 ± 2.15 cm, p < 0.001) having a greater reduction. There was a time by group interaction, with significant decreases in leptin (p < 0.001) and significant increases in adiponectin (p < 0.05) in the EXP group. CONCLUSIONS: Significant improvements in adipokines and leptin support the utility of exercise, diet, and fat loss for impacting inflammatory biomarkers. The improvement in adiponectin with EXP may suggest a unique health mechanism.

International society of sports nutrition position stand: nutrient timing.

The International Society of Sports Nutrition (ISSN) provides an objective and critical review regarding the timing of macronutrients in reference to healthy, exercising adults and in particular highly trained individuals on exercise performance and body composition. The following points summarize the position of the ISSN:Nutrient timing incorporates the use of methodical planning and eating of whole foods, fortified foods and dietary supplements. The timing of energy intake and the ratio of certain ingested macronutrients may enhance recovery and tissue repair, augment muscle protein synthesis (MPS), and improve mood states following high-volume or intense exercise.Endogenous glycogen stores are maximized by following a high-carbohydrate diet (8-12 g of carbohydrate/kg/day [g/kg/day]); moreover, these stores are depleted most by high volume exercise.If rapid restoration of glycogen is required (< 4 h of recovery time) then the following strategies should be considered:aggressive carbohydrate refeeding (1.2 g/kg/h) with a preference towards carbohydrate sources that have a high (> 70) glycemic indexthe addition of caffeine (3-8 mg/kg)combining carbohydrates (0.8 g/kg/h) with protein (0.2-0.4 g/kg/h) Extended (> 60 min) bouts of high intensity (> 70% VO2max) exercise challenge fuel supply and fluid regulation, thus carbohydrate should be consumed at a rate of ~30-60 g of carbohydrate/h in a 6-8% carbohydrate-electrolyte solution (6-12 fluid ounces) every 10-15 min throughout the entire exercise bout, particularly in those exercise bouts that span beyond 70 min. When carbohydrate delivery is inadequate, adding protein may help increase performance, ameliorate muscle damage, promote euglycemia and facilitate glycogen re-synthesis.Carbohydrate ingestion throughout resistance exercise (e.g., 3-6 sets of 8-12 repetition maximum [RM] using multiple exercises targeting all major muscle groups) has been shown to promote euglycemia and higher glycogen stores. Consuming carbohydrate solely or in combination with protein during resistance exercise increases muscle glycogen stores, ameliorates muscle damage, and facilitates greater acute and chronic training adaptations.Meeting the total daily intake of protein, preferably with evenly spaced protein feedings (approximately every 3 h during the day), should be viewed as a primary area of emphasis for exercising individuals.Ingestion of essential amino acids (EAA; approximately 10 g)either in free form or as part of a protein bolus of approximately 20-40 g has been shown to maximally stimulate muscle protein synthesis (MPS).Pre- and/or post-exercise nutritional interventions (carbohydrate + protein or protein alone) may operate as an effective strategy to support increases in strength and improvements in body composition. However, the size and timing of a pre-exercise meal may impact the extent to which post-exercise protein feeding is required.Post-exercise ingestion (immediately to 2-h post) of high-quality protein sources stimulates robust increases in MPS.In non-exercising scenarios, changing the frequency of meals has shown limited impact on weight loss and body composition, with stronger evidence to indicate meal frequency can favorably improve appetite and satiety. More research is needed to determine the influence of combining an exercise program with altered meal frequencies on weight loss and body composition with preliminary research indicating a potential benefit.Ingesting a 20-40 g protein dose (0.25-0.40 g/kg body mass/dose) of a high-quality source every three to 4 h appears to most favorably affect MPS rates when compared to other dietary patterns and is associated with improved body composition and performance outcomes.Consuming casein protein (~ 30-40 g) prior to sleep can acutely increase MPS and metabolic rate throughout the night without influencing lipolysis.

International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine.

Creatine is one of the most popular nutritional ergogenic aids for athletes. Studies have consistently shown that creatine supplementation increases intramuscular creatine concentrations which may help explain the observed improvements in high intensity exercise performance leading to greater training adaptations. In addition to athletic and exercise improvement, research has shown that creatine supplementation may enhance post-exercise recovery, injury prevention, thermoregulation, rehabilitation, and concussion and/or spinal cord neuroprotection. Additionally, a number of clinical applications of creatine supplementation have been studied involving neurodegenerative diseases (e.g., muscular dystrophy, Parkinson's, Huntington's disease), diabetes, osteoarthritis, fibromyalgia, aging, brain and heart ischemia, adolescent depression, and pregnancy. These studies provide a large body of evidence that creatine can not only improve exercise performance, but can play a role in preventing and/or reducing the severity of injury, enhancing rehabilitation from injuries, and helping athletes tolerate heavy training loads. Additionally, researchers have identified a number of potentially beneficial clinical uses of creatine supplementation. These studies show that short and long-term supplementation (up to 30 g/day for 5 years) is safe and well-tolerated in healthy individuals and in a number of patient populations ranging from infants to the elderly. Moreover, significant health benefits may be provided by ensuring habitual low dietary creatine ingestion (e.g., 3 g/day) throughout the lifespan. The purpose of this review is to provide an update to the current literature regarding the role and safety of creatine supplementation in exercise, sport, and medicine and to update the position stand of International Society of Sports Nutrition (ISSN).

A Two-Part Approach to Examine the Effects of Theacrine (TeaCrine®) Supplementation on Oxygen Consumption, Hemodynamic Responses, and Subjective Measures of Cognitive and Psychometric Parameters.

Theacrine (1,3,7,9-tetramethyluric acid) is a naturally occurring purine alkaloid, present in Camellia assamica variety kucha tea. Using a two-part approach in humans, the impact of theacrine (TeaCrine®, TC) was used to examine subjective dose-response, daily changes in cognitive and psychometric parameters, and changes in gas exchange and vital signs. All indicators were chosen to better ascertain the previously reported animal and human outcomes involving theacrine administration. Part 1 was a randomized, open-label, dose-response investigation in nine healthy participants whereby three participants ingested 400 mg TC per day and six participants ingested 200 mg/day. Participants recorded subjective changes in cognitive, psychometric, and exercise attributes using 150-mm anchored visual analog scale (VAS) before, and 1, 4, and 6 hours after ingestion every day for 7 consecutive days. Part 2 was a randomized, double-blind, placebo-controlled, crossover investigation in 15 healthy subjects in which all participants ingested a single 200 mg dose of TC or Placebo (PLA). Anchored VAS questionnaires were used to detect subjective changes in various aspects of physical and mental energy along with changes in gas exchange and hemodynamic parameters before, and 1, 2, and 3 hours after acute ingestion. Energy, focus, and concentration increased from baseline values in both doses with no dose-response effect. VAS responses in the 200 mg for willingness to exercise, anxiety, motivation to train and libido increased across the measurement period while no such change was seen with the 400 mg dose. After consuming a single 200 mg dose, significant group × time interaction effects were seen for energy, fatigue, and concentration. No changes in resting heart rate, gas exchange, systemic hemodynamics or side effect profiles were noted.

Effect of a Multi-Nutrient Over-the-Counter Supplement on Changes in Metabolic Rate and Markers of Lipolysis.

Using a prospective, randomized, double-blind, crossover study design, fifteen healthy male (n = 8) and female (n = 7) participants (mean ± standard deviation (SD): 28.3 ± 6.1 yr, 176.3 ± 11.4 cm, 89.8 ± 21.7 kg, 28.5 ± 4.8 kg/m2) completed this study. Two testing sessions occurred after an overnight fast and refraining from physical exercise. Prior to and 60, 120, and 180 minutes after single dose ingestion of placebo (PLA) or a Thermogenic Supplement (TS), visual analog scales (VAS), resting metabolic rate (VO2), and venous blood were collected. Resting heart rate and blood pressures were collected before, and 30, 60, 90, 120, 150 and 180 minutes after PLA or TS ingestion. Significant group × time interactions were found for VO2 with TS experiencing significant (p < 0.05) increases 60 and 120 minutes after ingestion. Respiratory quotient values tended to be lower 180 minutes (p = 0.07) after TS ingestion. TS group reported increased energy 60 minutes (p < 0.05) after ingestion. No interactions were reported for resting heart rate or blood pressure. Significant within-group reductions in systolic blood pressure were noted for PLA, while resting heart rates were significantly lower in TS 30 and 60 minutes after ingestion. An interaction for epinephrine (p = 0.02) was found, while no changes were reported for norepinephrine and dopamine. Dependent t-tests using area under the curve calculations revealed higher AUC values for epinephrine in TS compared to PLA (p = 0.001). In conclusion, ingestion of a single dose of TS increased oxygen consumption, epinephrine and energy levels, while substrate oxidation tended to change in comparison to a placebo. No adverse responses were reported.

International society of sports nutrition position stand: Beta-Alanine.

The International Society of Sports Nutrition (ISSN) provides an objective and critical review of the mechanisms and use of beta-alanine supplementation. Based on the current available literature, the conclusions of the ISSN are as follows: 1) Four weeks of beta-alanine supplementation (4-6 g daily) significantly augments muscle carnosine concentrations, thereby acting as an intracellular pH buffer; 2) Beta-alanine supplementation currently appears to be safe in healthy populations at recommended doses; 3) The only reported side effect is paraesthesia (tingling), but studies indicate this can be attenuated by using divided lower doses (1.6 g) or using a sustained-release formula; 4) Daily supplementation with 4 to 6 g of beta-alanine for at least 2 to 4 weeks has been shown to improve exercise performance, with more pronounced effects in open end-point tasks/time trials lasting 1 to 4 min in duration; 5) Beta-alanine attenuates neuromuscular fatigue, particularly in older subjects, and preliminary evidence indicates that beta-alanine may improve tactical performance; 6) Combining beta-alanine with other single or multi-ingredient supplements may be advantageous when supplementation of beta-alanine is high enough (4-6 g daily) and long enough (minimum 4 weeks); 7) More research is needed to determine the effects of beta-alanine on strength, endurance performance beyond 25 min in duration, and other health-related benefits associated with carnosine.

Effects of a dietary supplement on golf drive distance and functional indices of golf performance.

BACKGROUND: Limited research exists examining the impact of nutrition on golfing performance. This study's purpose was to determine the impact of daily supplementation with an over-the-counter dietary supplement on golf performance. METHODS: Healthy men (30.3 ± 6.9 y, 183.1 ± 5.6 cm, 86.7 ± 11.9 kg), with a 5-15 handicap were assigned in a double-blind, placebo-controlled manner to ingest for 30 days either a placebo (PLA, n = 13) or a dietary supplement containing creatine monohydrate, coffea arabica fruit extract, calcium fructoborate and vitamin D (Strong Drive™, SD, n = 14). Subjects ingested two daily doses for the first two weeks and one daily dose for the remaining two weeks. Participants followed their normal dietary habits and did not change their physical activity patterns. Two identical testing sessions in a pre/post fashion were completed consisting of a fasting blood sample, anthropometric measurements, 1-RM bench press, upper body power and golf swing performance using their driver and 7-iron. Data were analyzed using two-way mixed factorial ANOVAs and ANCOVA when baseline differences were present. Statistical significance was established a priori at p ≤ 0.05. RESULTS: ANCOVA revealed significantly greater (post-test) best drive distance (p = 0.04) for SD (+5.0% [+13.6 yards], ES = 0.75) as well as a tendency (p = 0.07) for average drive distance to increase (+8.4% [+19.6 yards], ES = 0.65), while no such changes were found with PLA (-0.5% [-1.2 yards], ES = 0.04 and +1.3% [+2.8 yards], ES = 0.08, respectively). Both groups experienced significant increases in body mass and 1-RM bench press (p < 0.001). No other significant group × time interactions were found. For the SD group only, within-group analysis confirmed significant improvements in set 1 average (+8.9%, p = 0.001) and peak velocity (+6.8%, p < =0.01). No changes were noted for reported adverse events, pain inventories, quality of life or any measured blood parameter. CONCLUSIONS: SD supplementation for 30 days significantly improved best drive distance more than placebo. Supplementation was well tolerated and did not result in any clinically significant changes in markers of health or adverse events/side effect profiles.

International Society of Sports Nutrition Position Stand: beta-hydroxy-beta-methylbutyrate (HMB).

Position Statement: The International Society of Sports Nutrition (ISSN) bases the following position stand on a critical analysis of the literature on the use of beta-hydroxy-beta-methylbutyrate (HMB) as a nutritional supplement. The ISSN has concluded the following. 1. HMB can be used to enhance recovery by attenuating exercise induced skeletal muscle damage in trained and untrained populations. 2. If consuming HMB, an athlete will benefit from consuming the supplement in close proximity to their workout. 3. HMB appears to be most effective when consumed for 2 weeks prior to an exercise bout. 4. Thirty-eight mg·kg·BM-1 daily of HMB has been demonstrated to enhance skeletal muscle hypertrophy, strength, and power in untrained and trained populations when the appropriate exercise prescription is utilized. 5. Currently, two forms of HMB have been used: Calcium HMB (HMB-Ca) and a free acid form of HMB (HMB-FA). HMB-FA may increase plasma absorption and retention of HMB to a greater extent than HMB-CA. However, research with HMB-FA is in its infancy, and there is not enough research to support whether one form is superior. 6. HMB has been demonstrated to increase LBM and functionality in elderly, sedentary populations. 7. HMB ingestion in conjunction with a structured exercise program may result in greater declines in fat mass (FM). 8. HMB's mechanisms of action include an inhibition and increase of proteolysis and protein synthesis, respectively. 9. Chronic consumption of HMB is safe in both young and old populations.

Antioxidant effects of a cinnamon extract in people with impaired fasting glucose that are overweight or obese.

OBJECTIVE: To determine the effects of a dried aqueous extract of cinnamon on antioxidant status of people with impaired fasting glucose that are overweight or obese. METHODS: Twenty-two subjects, with impaired fasting blood glucose with BMI ranging from 25 to 45, were enrolled in a double-blind placebo-controlled trial. Subjects were given capsules containing either a placebo or 250 mg of an aqueous extract of cinnamon (Cinnulin PF) two times per day for 12 weeks. Plasma malondialdehyde (MDA) concentrations were assessed using high performance liquid chromatography and plasma antioxidant status was evaluated using ferric reducing antioxidant power (FRAP) assay. Erythrocyte Cu-Zn superoxide (Cu-Zn SOD) activity was measured after hemoglobin precipitation by monitoring the auto-oxidation of pyrogallol and erythrocyte glutathione peroxidase (GPx) activity by established methods. RESULTS: FRAP and plasma thiol (SH) groups increased, while plasma MDA levels decreased in subjects receiving the cinnamon extract. Effects were larger after 12 than 6 weeks. There was also a positive correlation (r = 0.74; p = 0.014) between MDA and plasma glucose. CONCLUSION: This study supports the hypothesis that the inclusion of water soluble cinnamon compounds in the diet could reduce risk factors associated with diabetes and cardiovascular disease.

Water-soluble vitamins: research update.

For more than 50 years, the Food and Nutrition Board of the National Academy of Sciences has been reviewing nutrition research and defining nutrient requirements for healthy people, referred to as the recommended dietary allowances (RDA). As new nutrition research is published, the importance of vitamins as vital nutrients is underscored, and new physiologic roles and applications to human health are examined and considered with regard to updating the RDA. Each year a substantial amount of research is published on vitamins. This article examines and summarizes noteworthy research published on individual water-soluble vitamins (excluding vitamin C) in the past 12 months, provides relevant background information on these vitamins, and offers critical reviews as appropriate.

Effects of ribose supplementation on repeated sprint performance in men.

This study used a randomized, placebo-controlled, crossover design to evaluate the effects of oral ribose supplementation on short-term anaerobic performance. After familiarization, subjects performed 2 bouts of repeated cycle sprint exercise (six 10-second sprints with 60-second rest periods between sprints) in a single day. After the second exercise, bout subjects ingested 32 g of ribose or cellulose (4 x 8-g doses) during the next 36 hours. After supplementation, subjects returned to the laboratory to perform a single bout of cycle sprinting (as described above). After a 5-day washout period, subjects repeated the protocol, receiving the opposite supplement treatment. Ribose supplementation lead to statistically significant increases in mean power and peak power in sprint 2 (10.9 and 6.6%, respectively) and higher (although not significant) absolute values in sprints 1, 3, and 4. In conclusion, ribose supplementation did not show reproducible increases in performance across all 6 sprints. Therefore, within the framework of this investigation, it appears that ribose supplementation does not have a consistent or substantial effect on anaerobic cycle sprinting.

Effects of prohormone supplementation in humans: a review.

Despite a relative dearth of information on their effects, supplementation with prohormones has become a popular practice. Unlike synthetic anabolic-androgenic steroids, many of these over-the-counter androgens are produced endogenously by adrenal, gonadal and peripheral steroidogenic pathways as part of the normal sexual and reproductive hormonal milieu. It has been contended that peripheral enzymatic conversion of these prohormones to testosterone or nortestosterone (via ingestion of androstenedione/androstenediol or 19-nor-androstenedione/androstenediol, respectively) might lead to anabolic and/or ergogenic effects. Existing data suggest that acute oral ingestion of >or=200 mg androstenedione or androstenediol modestly and transiently increases serum testosterone concentrations in men; however, this is accompanied by greater increases in circulating estrogen(s). At doses < 300 mg/d, oral supplementation for as long as 12-weeks with androstenedione or androstenediol has no effect on body composition or physical performance and decreases high-density lipoprotein cholesterol. Similarly, oral supplementation with norandrostenedione and norandrostenediol for up to eight weeks has no effect on body composition or physical performance. In light of these data, new products have been developed that use alternative modes of prohormone administration (sublingual/transbuccal and cyclodextrin-complexation). Future studies should critically examine the effects of these approaches. However, within the framework of the research reviewed, over-the-counter oral prohormone supplementation is ineffective at increasing muscle mass or athletic performance. As a result of the potential health concerns that have been raised, the risk to benefit ratio of using these substances orally seems unfavorable.

Effect of creatine loading on anaerobic performance and skeletal muscle volume in NCAA Division I athletes.

OBJECTIVE: We measured the effect of 3 d of creatine (Cr) supplementation on repeated sprint performance and thigh muscle volume in elite power athletes. METHODS: Ten male (mean +/- standard deviation of body mass and percentage of fat (81.1 +/- 10.5 kg and 9.8 +/- 3.5) and ten female (58.4 +/- 5.3 kg and 15.0 +/- 3.4) athletes were matched for sex and 10-s cycle sprint scores, paired by rank, and randomly assigned to the Cr or placebo (P) group. Subjects completed six maximal 10-s cycle sprints interspersed with 60 s of recovery before and after 3 d of Cr (0.35 g/kg of fat-free mass) or P (maltodextrin) ingestion. Before and after supplementation, 10 contiguous transaxial images of both thighs were obtained with magnetic resonance imaging. RESULTS: Cr supplementation resulted in statistically significant increases in body mass (0.9 +/- 0.1 kg, P < 0.03), total work during the first sprint (P < 0.04), and peak power during sprints 2 to 6 (P < 0.10). As expected, total work and peak power values for males were greater than those for their female counterparts during the initial sprint (P < 0.02); however, the reverse was true during the last three sprints (P < 0.01). Imaging data showed a 6.6% increase in thigh volume in five of six Cr subjects (P = 0.05). CONCLUSION: These data indicate that 3 d of Cr supplementation can increase thigh muscle volume and may enhance cycle sprint performance in elite power athletes; moreover, this effect is greater in females as sprints are repeated.