Eight Weeks of a High Dose of Curcumin Supplementation May Attenuate Performance Decrements Following Muscle-Damaging Exercise

Background: It is known that unaccustomed exercise—especially when it has an eccentric component—causes muscle damage and subsequent performance decrements. Attenuating muscle damage may improve performance and recovery, allowing for improved training quality and adaptations. Therefore, the current study sought to examine the effect of two doses of curcumin supplementation on performance decrements following downhill running. Methods: Sixty-three physically active men and women (21 ± 2 y; 70.0 ± 13.7 kg; 169.3 ± 15.2 cm; 25.6 ± 14.3 body mass index (BMI), 32 women, 31 men) were randomly assigned to ingest 250 mg of CurcuWIN® (50 mg of curcuminoids), 1000 mg of CurcuWIN® (200 mg of curcuminoids), or a corn starch placebo (PLA) for eight weeks in a double-blind, randomized, placebo-controlled parallel design. At the end of the supplementation period, subjects completed a downhill running protocol intended to induce muscle damage. Muscle function using isokinetic dynamometry and perceived soreness was assessed prior to and at 1 h, 24 h, 48 h, and 72 h post-downhill run. Results: Isokinetic peak extension torque did not change in the 200-mg dose, while significant reductions occurred in the PLA and 50-mg groups through the first 24 h of recovery. Isokinetic peak flexion torque and power both decreased in the 50-mg group, while no change was observed in the PLA or 200-mg groups. All the groups experienced no changes in isokinetic extension power and isometric average peak torque. Soreness was significantly increased in all the groups compared to the baseline. Non-significant improvements in total soreness were observed for the 200-mg group, but these changes failed to reach statistical significance. Conclusion: When compared to changes observed against PLA, a 200-mg dose of curcumin attenuated reductions in some but not all observed changes in performance and soreness after completion of a downhill running bout. Additionally, a 50-mg dose appears to offer no advantage to changes observed in the PLA and 200-mg groups

A Pilot Study to Examine the Impact of Beta-Alanine Supplementation on Anaerobic Exercise Performance in Collegiate Rugby Athletes

Beta-alanine (BA) is a precursor to carnosine which functions as a buffer assisting in the maintenance of intracellular pH during high-intensity efforts. Rugby is a sport characterized by multiple intermittent periods of maximal or near maximal efforts with short periods of rest/active recovery. The purpose of this pilot study was to evaluate the impact of six weeks of beta-alanine supplementation on anaerobic performance measures in collegiate rugby players. Twenty-one male, collegiate rugby players were recruited, while fifteen completed post-testing (Mean ± SD; Age: 21.0 ± 1.8 years, Height: 179 ± 6.3 cm, Body Mass: 91.8 ± 13.3 kg, % Body Fat: 21.3 ± 4.4). Supplementation was randomized in a double-blind, placebo-controlled manner between 6.4 g/d of beta-alanine and 6.4 g/d of maltodextrin placebo. Body composition, upper and lower-body maximal strength and muscular endurance, intermittent sprint performance, and post-exercise lactate, heart rate, and rating of perceived exertion were assessed before and after supplementation. Data were analyzed using a 2 × 2 (group × time) mixed factorial analysis of variance (ANOVA) with repeated measures on time. No significant interaction effects were noted for body mass, fat mass, fat-free mass, and percent bodyfat (p \u3e 0.05). No performance effects resulting from beta-alanine supplementation were detected. Results from this initial pilot investigation suggest that BA exerts little to no impact on body composition parameters, muscular strength, muscular endurance, or intermittent sprinting performance. With the limited research exploring the impact of BA in this sporting context, these initial findings offer little support for BA use, but more research is needed to fully understand the potential impact of BA on various aspects of resistance exercise performance

Eight Weeks of a High Dose of Curcumin Supplementation May Attenuate Performance Decrements Following Muscle-Damaging Exercise

Background: It is known that unaccustomed exercise—especially when it has an eccentric component—causes muscle damage and subsequent performance decrements. Attenuating muscle damage may improve performance and recovery, allowing for improved training quality and adaptations. Therefore, the current study sought to examine the effect of two doses of curcumin supplementation on performance decrements following downhill running. Methods: Sixty-three physically active men and women (21 ± 2 y; 70.0 ± 13.7 kg; 169.3 ± 15.2 cm; 25.6 ± 14.3 body mass index (BMI), 32 women, 31 men) were randomly assigned to ingest 250 mg of CurcuWIN® (50 mg of curcuminoids), 1000 mg of CurcuWIN® (200 mg of curcuminoids), or a corn starch placebo (PLA) for eight weeks in a double-blind, randomized, placebo-controlled parallel design. At the end of the supplementation period, subjects completed a downhill running protocol intended to induce muscle damage. Muscle function using isokinetic dynamometry and perceived soreness was assessed prior to and at 1 h, 24 h, 48 h, and 72 h post-downhill run. Results: Isokinetic peak extension torque did not change in the 200-mg dose, while significant reductions occurred in the PLA and 50-mg groups through the first 24 h of recovery. Isokinetic peak flexion torque and power both decreased in the 50-mg group, while no change was observed in the PLA or 200-mg groups. All the groups experienced no changes in isokinetic extension power and isometric average peak torque. Soreness was significantly increased in all the groups compared to the baseline. Non-significant improvements in total soreness were observed for the 200-mg group, but these changes failed to reach statistical significance. Conclusion: When compared to changes observed against PLA, a 200-mg dose of curcumin attenuated reductions in some but not all observed changes in performance and soreness after completion of a downhill running bout. Additionally, a 50-mg dose appears to offer no advantage to changes observed in the PLA and 200-mg groups

Acute effects of ingesting a commercial thermogenic drink on changes in energy expenditure and markers of lipolysis

Background: To determine the acute effects of ingesting a thermogenic drink (Celsius, Delray Beach, FL) (TD) on changes in metabolism and lipolysis. Methods: Healthy college-aged male (23.2 ± 4.0 y, 177.2 ± 6.1 cm, 81.7 ± 11.3 kg, 22.8 ± 7.3 % fat; n = 30) and female (23.4 ± 3.1 y, 165.6 ± 8.7 cm, 62.1 ± 9.9 kg, 28.3 ± 7.4 % fat; n = 30) participants were matched according to height and weight to consume 336 ml of the TD or a noncaloric, non-caffeinated placebo (PLA). After a 12 h fast, participants reported for pre-consumption measures of height, weight, heart rate, blood pressure, resting energy expenditure (REE), respiratory exchange ratio (RER), glycerol and free-fatty acid (FFA) concentrations. REE and RER were determined at 60, 120, and 180 min post-consumption. Serum glycerol and FFA concentrations were determined at 30, 60, 120 and 180 min post-consumption. Results: When compared to PLA, TD significantly increased REE at 60, 120 and 180 min (p < 0.05). FFA concentrations were significantly greater in TD compared to PLA at 30, 60, 120 and 180 min post-consumption (p < 0.05). No between-group differences were found in RER. Conclusion: Acute TD ingestion significantly increased REE, FFA and glycerol appearance. If sustained, these changes may help to promote weight loss and improve body composition; however, these findings are currently unknown as are the general safety and efficacy of prolonged consumption

Effects of creatine monohydrate timing on resistance training adaptations and body composition after 8 weeks in male and female collegiate athletes

Background: Limited research is available on the potential impact of creatine monohydrate administration before or after workouts among athletes. This study aimed to investigate the effects of pre- vs. post-exercise creatine monohydrate supplementation on resistance training adaptations and body composition. Methods: In a randomized, double-blind, placebo-controlled, parallel design, 34 healthy resistance-trained male and female athletes were randomly assigned and matched according to fat free mass to consume a placebo, or 5-g dose of creatine monohydrate within 1 h before training, or within 1 h after training for 8 weeks, while completing a weekly resistance training program. Participants co-ingested 25-gram doses of both whey protein isolate and maltodextrin along with each assigned supplement dose. Body composition, muscular strength, and endurance, along with isometric mid-thigh pull were assessed before and after the 8-week supplementation period. A 3 × 2 mixed factorial (group x time) ANOVA with repeated measures on time were used to evaluate differences. Results: All groups experienced similar and statistically significant increases in fat free mass (+1.34 ± 3.48 kg, p = 0.04), upper (+2.21 ± 5.69 kg, p = 0.04) and lower body strength (+7.32 ± 10.01 kg, p \u3c 0.001), and decreases in body mass (−1.09 ± 2.71 kg, p = 0.03), fat mass (−2.64 ± 4.16 kg, p = 0.001), and percent body fat (−2.85 ± 4.39 kg, p \u3c 0.001). Conclusions: The timing of creatine monohydrate did not exert any additional influence over the measured outcomes

Contributing Factors to Low Energy Availability in Female Athletes: A Narrative Review of Energy Availability, Training Demands, Nutrition Barriers, Body Image, and Disordered Eating

Relative Energy Deficiency in sport is experiencing remarkable popularity of late, particularly among female athletes. This condition is underpinned by low energy availability, which is a byproduct of high energy expenditure, inadequate energy intake, or a combination of the two. Several contributing factors exist that may predispose an athlete to low energy availability, and therefore a holistic and comprehensive assessment may be required to identify the root causes. The focus of the current narrative review is to discuss the primary contributing factors as well as known risk factors for low energy availability among female athletes to help practitioners increase awareness on the topic and identify future areas of focus

Timing of ergogenic aids and micronutrients on muscle and exercise performance

The timing of macronutrient ingestion in relation to exercise is a purported strategy to augment muscle accretion, muscle and athletic performance, and recovery. To date, the majority of macronutrient nutrient timing research has focused on carbohydrate and protein intake. However, emerging research suggests that the strategic ingestion of various ergogenic aids and micronutrients may also have beneficial effects. Therefore, the purpose of this narrative review is to critically evaluate and summarize the available literature examining the timing of ergogenic aids (caffeine, creatine, nitrates, sodium bicarbonate, beta-alanine) and micronutrients (iron, calcium) on muscle adaptations and exercise performance. In summary, preliminary data is available to indicate the timing of caffeine, nitrates, and creatine monohydrate may impact outcomes such as exercise performance, strength gains and other exercise training adaptations. Furthermore, data is available to suggest that timing the administration of beta-alanine and sodium bicarbonate may help to minimize known untoward adverse events while maintaining potential ergogenic outcomes. Finally, limited data indicates that timed ingestion of calcium and iron may help with the uptake and metabolism of these nutrients. While encouraging, much more research is needed to better understand how timed administration of these nutrients and others may impact performance, health, or other exercise training outcomes

Absorption kinetics of berberine and dihydroberberine and their impact on glycemia: A randomized, controlled, crossover pilot trial

Berberine is a natural alkaloid used to improve glycemia but displays poor bioavailability and increased rates of gastrointestinal distress at higher doses. Recently, dihydroberberine has been developed to combat these challenges. This study was designed to determine the rate and extent to which berberine appeared in human plasma after oral ingestion of a 500 mg dose of berberine (B500) or 100 mg and 200 mg doses of dihydroberberine (D100 and D200). In a randomized, double-blind, crossover fashion, five males (26 ± 2.6 years; 184.2 ± 11.6 cm; 91.8 ± 10.1 kg; 17.1 ± 3.5% fat) completed a four-dose supplementation protocol of placebo (PLA), B500, D100, and D200. The day prior to their scheduled visit, participants ingested three separate doses with breakfast, lunch, and dinner. Participants fasted overnight (8–10 h) and consumed their fourth dose with a standardized test meal (30 g glucose solution, 3 slices white bread) after arrival. Venous blood samples were collected 0, 20, 40, 60, 90, and 120 minutes (min) after ingestion and analyzed for BBR, glucose, and insulin. Peak concentration (CMax) and area under the curve (AUC) were calculated for all variables. Baseline berberine levels were different between groups (p = 0.006), with pairwise comparisons indicating that baseline levels of PLA and B500 were different than D100. Berberine CMax tended to be different (p = 0.06) between all conditions. Specifically, the observed CMax for D100 (3.76 ± 1.4 ng/mL) was different than PLA (0.22 ± 0.18 ng/mL, p = 0.005) and B500 (0.4 ± 0.17 ng/mL, p = 0.005). CMax for D200 (12.0 ± 10.1 ng/mL) tended (p = 0.06) to be different than B500. No difference in CMax was found between D100 and D200 (p = 0.11). Significant differences in berberine AUC were found between D100 (284.4 ± 115.9 ng/mL × 120 min) and PLA (20.2 ± 16.2 ng/mL × 120 min, p = 0.007) and between D100 and B500 (42.3 ± 17.6 ng/mL × 120 min, p = 0.04). Significant differences in D100 BBR AUC (284.4 ± 115.9 ng/mL×120 min) were found between PLA (20.2 ± 16.2 ng/mL × 120 min, p = 0.042) and B500 (42.3 ± 17.6 ng/mL × 120 min, p = 0.045). Berberine AUC values between D100 and D200 tended (p = 0.073) to be different. No significant differences in the levels of glucose (p = 0.97) and insulin (p = 0.24) were observed across the study protocol. These results provide preliminary evidence that four doses of a 100 mg dose of dihydroberberine and 200 mg dose of dihydroberberine produce significantly greater concentrations of plasma berberine across of two-hour measurement window when compared to a 500 mg dose of berberine or a placebo. The lack of observed changes in glucose and insulin were likely due to the short duration of supplementation and insulin responsive nature of study participants. Follow-up efficacy studies on glucose and insulin changes should be completed to assess the impact of berberine and dihydroberberine supplementation in overweight, glucose intolerant populations

Nutrient Status and perceptions of energy and macronutrient intake in a Group of Collegiate Female Lacrosse Athletes

Background The purpose of this study was to compare nutritional intakes against recommended values as well as between the perceived intake and needs of female lacrosse players. Methods Twenty female NCAA Division II lacrosse players (20.0 ± 1.7 yrs., 169.7 ± 6.4 cm; 69.9 ± 10.7 kg; 27.5 ± 3.3% fat) completed a four-day monitoring period during in-season. Athletes were outfitted with an activity monitor over four consecutive days and completed four-day food records to assess total daily energy expenditure (TDEE) and dietary intake. Body composition was assessed and used to calculate recommended dietary intakes. Actual intake was self-reported using a commercially available food tracking program (MyFitnessPal©, USA). Daily average values were calculated for total and relative energy, protein, carbohydrate, and fat intake. These values were then compared to published nutritional recommendations established by the International Society of Sports Nutrition. Appropriate pairwise comparisons were made depending on the normality of the distribution. Results Athletes ate significantly less than recommended values for energy, carbohydrates and protein. (p \u3c 0.001). Significant discrepancies (p \u3c 0.001) were also observed between perceptions of intake versus actual intake. Conclusions Athletes significantly underestimated perceived intake of dietary fat and carbohydrate when compared to perceived needs. Massive standard deviations and ranges were observed, suggesting that some athletes lack a basic understanding of their daily needs. Results from this data suggest that collegiate athletes lack appropriate understanding of basic nutrition needs and could benefit from basic nutrition education as it pertains to their health and performance

Efficacy and safety of a popular thermogenic drink after 28 days of ingestion

Background: We have recently demonstrated that consuming a thermogenic drink (TD) acutely increases energy expenditure and serum markers of lipolysis in healthy, college-aged individuals. The purpose of this study was to determine if consuming TD over 28 days affects its acute thermogenic and lipolytic effects as well as body composition and clinical chemistry safety markers. Methods: Sixty healthy, males (mean ± SE; 23 ± 1 years, 177 ± 2 cm, 81.7 ± 2.1 kg, 22.8 ± 1.4% body fat; n = 30) and females (23 ± 1 years, 166 ± 2 cm, 62.1 ± 1.8 kg, 28.3 ± 1.4% body fat; n = 30) reported to the laboratory on day 0 (T1) for determination of body composition, resting energy expenditure (REE) as well as glycerol and free fatty acid (FFA) levels before and after ingesting either 336 ml of TD or a non-caloric, non-caffeinated placebo (PLA) drink. Following day 0, participants supplemented daily with 336 ml•day-1 of either TD or PLA and repeated identical testing procedures on day 28 (T2). Day 28 area under the curve (AUC) values were calculated for REE, FFA, and glycerol. Day 28 acute data and prolonged AUC comparisons between groups were analyzed using ANOVAs with repeated measures. Results: Percent body fat (p = 0.02) and fat mass (p = 0.01) decreased in the TD group compared to the PLA group after 28 days. Day 28 FFA AUC values (p = 0.048) were greater in the TD group compared to the PLA group. There was no significant difference in day 28 REE AUC values (p = 0.30) or glycerol AUC values (p = 0.21), although a significant increase in REE values in the PLA group may have confounded these findings. There were no differences between groups concerning blood and clinical safety markers. Conclusion: Within-group elevations in FFA and REE values in the TD group were still evident following a 28-day supplementation period which may contribute to the observed decrements in %BF. Further, prolonged TD supplementation did not alter the assessed clinical safety markers. Future studies should examine the synergistic and independent effects of the active ingredients in addition to effects of longer ingestion periods of TD ingestion with or without exercise at promoting and sustaining changes in body composition