Search

Objective To examine differences in the frequency and severity of federally reported adverse events between caffeine-containing and non–caffeine-containing products while also identifying the category of caffeine-containing products associated with the highest frequency and severity of adverse events. Patients and Methods All adverse event reports that met specified eligibility criteria and were submitted to the Center for Food Safety and Applied Nutrition Adverse Event Reporting System between January 1, 2014, and June 29, 2018, were extracted. In this retrospective observational study, the most severe adverse event experienced, an ordinal variable, was categorized into death, life-threatening, hospitalization/disability, and emergency department visit. A nonproportional odds model was used to compare the odds of caffeine-containing products being associated with more severe adverse events relative to a noncaffeine group. The analysis is of data only from those reporting adverse events and may or may not be representative of the entire population exposed to these products, which is not known from the examined data. Results Energy and preworkout products saw a significant increase in the odds of the adverse event experienced being death rather than the other less severe outcomes relative to the noncaffeinated group. Those products, along with weight loss products, had greater odds of the adverse event being death or life-threatening vs the less severe outcomes relative to the noncaffeinated group. Conclusion Caffeine-containing products have a greater association with severe adverse events compared with non–caffeine-containing products. Exposure to preworkout and weight loss products had greater odds of being associated with a more serious adverse event relative to noncaffeinated products. Health care practitioners should use these outcomes to better inform and educate patients about the many factors related to caffeine intake and adverse outcomes.

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.

Jagim, AR, Camic, CL, Askow, A, Luedke, J, Erickson, J, Kerksick, CM, Jones, MT, and Oliver, JM. Sex differences in resting metabolic rate among athletes. J Strength Cond Res 33(11): 3008-3014, 2019-The purpose of this study was to compare differences in resting metabolic rate (RMR) between sexes in Division III National Collegiate Athletic Association (NCAA) collegiate athletes and to identify predictors of RMR. Sixty-eight male (M) (age: 20.1 ± 1.5 years; height: 181.8 ± 5.9 cm; body mass (BM): 93.7 ± 16.3 kg; and body fat%: 16.3 ± 8.6%) and 48 female (F) athletes (age: 19.4 ± 1.3 years; height: 166.5 ± 6.0 cm; BM: 63.4 ± 12.7 kg; and body fat%: 21.5 ± 6.3%) participated in a single day of testing, which included determination of RMR using indirect calorimetry and air displacement plethysmography to measure fat mass and fat-free mass (FFM). An independent-samples t-test was used to compare differences in body composition and RMR between sexes, and regression analysis was used to identify predictors of RMR. Men had a significantly higher absolute RMR (M: 2,481 ± 209 vs. F: 1,553 ± 193 kcals·d; p < 0.001), but when adjusted for BM (M: 25.6 ± 8.3 vs. F: 25.9 ± 2.5 kcals·kg BM per day; p = 0.82) and FFM (M: 31.1 ± 10.6 vs. F: 33.6 ± 3.8 kcals·kg FFM per day; p = 0.12), these differences became nonsignificant. Regression analysis indicated that BM in both men (β = 0.73) and women (β = 0.88) was the strongest predictor of RMR. The results of the current study indicate minimal differences in RMR between sexes among athletic populations when adjusted for BM and FFM. In the current group of athletes, BM seems to account for the largest variability in RMR.

Currier, BS, Harty, PS, Zabriskie, HA, Stecker, RA, Moon, JM, Jagim, AR, and Kerksick, CM. Fat-free mass index in a diverse sample of male collegiate athletes. J Strength Cond Res 33(6): 1474-1479, 2019-Fat-free mass index (FFMI) is a body composition metric that has been used to assess relative muscularity in athletes. Fat-free mass index is calculated by dividing FFM by height squared, although further height corrections through linear regression may be needed in taller individuals. This study reported height-adjusted FFMI (FFMIAdj) data in 209 male collegiate athletes from 10 sports (baseball, cross country, football, golf, ice hockey, weightlifting, rugby, swimming, track and field, and water polo) and the FFMIAdj natural upper limit for sports with sufficient sample size. The body composition of all subjects (mean ± SD; age: 20.7 ± 1.9 years, height: 182.9 ± 6.7 cm, body mass: 90.8 ± 16.8 kg, and percent body fat: 15.6 ± 5.3) was measured using dual-energy x-ray absorptiometry. Linear regression was used to adjust for height, and the FFMIAdj natural upper limit was determined by calculating the 97.5th percentile of all values. One-way analyses of variance with Games-Howell post hoc comparisons were used to determine between-sport differences. A paired-samples t-test revealed a significant difference (p < 0.001) between unadjusted and adjusted mean FFMI values. The overall mean FFMIAdj was 22.8 ± 2.8 kg·m. Significant between-sport differences (p < 0.001) in FFMIAdj were identified. Average FFMIAdj was highest in football athletes (24.28 ± 2.39 kg·m) and lowest in water polo athletes (20.68 ± 3.56 kg·m). The FFMIAdj upper limit was calculated for all athletes (28.32 kg·m), rugby (29.1 kg·m), and baseball (25.5 kg·m). This study reported FFMIAdj values in a diverse cohort of male collegiate athletes, providing data for the first time in several sports. These values can be used to guide nutritional and exercise interventions, predict athletic performance, and provide coaches with standardized information regarding the potential for further FFM accretion in male athletes.

Exercise-induced muscle damage (EIMD) is typically caused by unaccustomed exercise and results in pain, soreness, inflammation, and reduced muscle function. These negative outcomes may cause discomfort and impair subsequent athletic performance or training quality, particularly in individuals who have limited time to recover between training sessions or competitions. In recent years, a multitude of techniques including massage, cryotherapy, and stretching have been employed to combat the signs and symptoms of EIMD, with mixed results. Likewise, many varied nutritional and supplementation interventions intended to treat EIMD-related outcomes have gained prominence in the literature. To date, several review articles have been published that explore the many recovery strategies purported to minimize indirect markers of muscle damage. However, these articles are very limited from a nutritional standpoint. Thus, the purpose of this review is to briefly and comprehensively summarize many of these strategies that have been shown to positively influence the recovery process after damaging exercise. These strategies have been organized into the following sections based on nutrient source: fruits and fruit-derived supplements, vegetables and plant-derived supplements, herbs and herbal supplements, amino acid and protein supplements, vitamin supplements, and other supplements.

Adequate dietary protein is important for many aspects of health with current evidence suggesting that exercising individuals need greater amounts of protein. When assessing protein quality, animal sources of protein routinely rank amongst the highest in quality, largely due to the higher levels of essential amino acids they possess in addition to exhibiting more favorable levels of digestibility and absorption patterns of the amino acids. In recent years, the inclusion of plant protein sources in the diet has grown and evidence continues to accumulate on the comparison of various plant protein sources and animal protein sources in their ability to stimulate muscle protein synthesis (MPS), heighten exercise training adaptations, and facilitate recovery from exercise. Without question, the most robust changes in MPS come from efficacious doses of a whey protein isolate, but several studies have highlighted the successful ability of different plant sources to significantly elevate resting rates of MPS. In terms of facilitating prolonged adaptations to exercise training, multiple studies have indicated that a dose of plant protein that offers enough essential amino acids, especially leucine, consumed over 8–12 weeks can stimulate similar adaptations as seen with animal protein sources. More research is needed to see if longer supplementation periods maintain equivalence between the protein sources. Several practices exist whereby the anabolic potential of a plant protein source can be improved and generally, more research is needed to best understand which practice (if any) offers notable advantages. In conclusion, as one considers the favorable health implications of increasing plant intake as well as environmental sustainability, the interest in consuming more plant proteins will continue to be present. The evidence base for plant proteins in exercising individuals has seen impressive growth with many of these findings now indicating that consumption of a plant protein source in an efficacious dose (typically larger than an animal protein) can instigate similar and favorable changes in amino acid update, MPS rates, and exercise training adaptations such as strength and body composition as well as recovery.

Creatine is one of the most studied and popular ergogenic aids for athletes and recreational weightlifters seeking to improve sport and exercise performance, augment exercise training adaptations, and mitigate recovery time. Studies consistently reveal that creatine supplementation exerts positive ergogenic effects on single and multiple bouts of short-duration, high-intensity exercise activities, in addition to potentiating exercise training adaptations. In this respect, supplementation consistently demonstrates the ability to enlarge the pool of intracellular creatine, leading to an amplification of the cell’s ability to resynthesize adenosine triphosphate. This intracellular expansion is associated with several performance outcomes, including increases in maximal strength (low-speed strength), maximal work output, power production (high-speed strength), sprint performance, and fat-free mass. Additionally, creatine supplementation may speed up recovery time between bouts of intense exercise by mitigating muscle damage and promoting the faster recovery of lost force-production potential. Conversely, contradictory findings exist in the literature regarding the potential ergogenic benefits of creatine during intermittent and continuous endurance-type exercise, as well as in those athletic tasks where an increase in body mass may hinder enhanced performance. The purpose of this review was to summarize the existing literature surrounding the efficacy of creatine supplementation on exercise and sports performance, along with recovery factors in healthy populations.

Glucosamine (GLU) is a natural compound found in cartilage, and supplementation with glucosamine has been shown to improve joint heath and has been linked to reduced mortality rates. GLU is poorly absorbed and may exhibit functional properties in the gut. The purpose of this study was to examine the impact of glucosamine on gastrointestinal function as well as changes in fecal microbiota and metabolome. Healthy males (n = 6) and females (n = 5) (33.4 ± 7.7 years, 174.1 ± 12.0 cm, 76.5 ± 12.9 kg, 25.2 ± 3.1 kg/m2, n = 11) completed two supplementation protocols that each spanned three weeks separated by a washout period that lasted two weeks. In a randomized, double-blind, placebo-controlled, crossover fashion, participants ingested a daily dose of GLU hydrochloride (3000 mg GlucosaGreen®, TSI Group Ltd., Missoula, MT, USA) or maltodextrin placebo. Study participants completed bowel habit and gastrointestinal symptoms questionnaires in addition to providing a stool sample that was analyzed for fecal microbiota and metabolome at baseline and after the completion of each supplementation period. GLU significantly reduced stomach bloating and showed a trend towards reducing constipation and hard stools. Phylogenetic diversity (Faith’s PD) and proportions of Pseudomonadaceae, Peptococcaceae, and Bacillaceae were significantly reduced following GLU consumption. GLU supplementation significantly reduced individual, total branched-chain, and total amino acid excretion, with no glucosamine being detected in any of the fecal samples. GLU had no effect on fecal short-chain fatty acids levels. GLU supplementation provided functional gut health benefits and induced fecal microbiota and metabolome changes.

Sport nutrition knowledge has been shown to influence dietary habits of athletes. The purpose of the current study was to examine relationships between sport nutrition knowledge and body composition and examine potential predictors of body weight goals in collegiate athletes. Participants included National Collegiate Athletic Association Division III women (n = 42, height: 169.9 ± 6.9 cm, body mass: 67.1 ± 8.6 kg, fat-free mass: 51.3 ± 6.6 kg, body fat per cent: 24.2 ± 5.3%) and men (n = 25, height: 180.8 ± 7.2 cm, body mass: 89.2 ± 20.5 kg, fat-free mass: 75.9 ± 12.2 kg, body fat per cent: 13.5 ± 8.9%) athletes. Body composition was assessed via air displacement plethysmography. Athletes completed a validated questionnaire designed to assess sport nutrition knowledge and were asked questions about their perceived dietary energy and macronutrient requirements, as well as their body weight goal (i.e., lose, maintain, gain weight). Athletes answered 47.98 ± 11.29% of questions correctly on the nutrition questionnaire with no differences observed between sexes (men: 49.52 ± 11.76% vs. women: 47.03 ± 11.04%, p = 0.40). An inverse relationship between sport nutrition knowledge scores and body fat percentage (BF%) (r = –0.330, p = 0.008), and fat mass (r = –.268, p = 0.032) was observed for all athletes. Fat mass (β = 0.224), BF% (β = 0.217), and body mass index (BMI) (β = 0.421) were all significant (p &lt, 0.05) predictors of body weight goal in women. All athletes significantly (p &lt, 0.001) underestimated daily energy (–1,360 ± 610.2 kcal/day), carbohydrate (–301.6 ± 149.2 grams/day [g/day]), and fat (–41.4 ± 34.5 g/day) requirements. Division III collegiate athletes have a low level of sport nutrition knowledge, which was associated with a higher BF%. Women athletes with a higher body weight, BF% and BMI were more likely to select weight loss as a body weight goal. Athletes also significantly underestimated their energy and carbohydrate requirements based upon the demands of their sport, independent of sex.

The purpose of this study was to assess autonomic and hemodynamic recovery in women who performed moderate-intensity exercise in heat. Seven women (31.7 ± 7.6 years, 67.5 ± 4.4 kg, 25.7 ± 5.6% Fat, 43.9 ± 5.1 mL/kg/min) completed two identical bouts of graded treadmill walking (~60% VO(2)peak). One bout was hot (37.5 ± 1.4°C, 46.5 ± 4.6% relative humidity (RH)), and the other was moderate (20.7 ± 1.1°C, 29.9 ± 4.1% RH). For 24 h before and one h after each bout, participants had heart rate variability monitored. After each exercise bout HR and BP were measured during 30 min of supine recovery and 10 min of orthostatic challenge. HF power and RMSSD were lower and LF power and LF:HF ratio greater following exercise in the heat and remained different from the moderate condition for 30 min (p

Creatine is a popular ergogenic aid among athletic populations with consistent evidence indicating that creatine supplementation also continues to be commonly used among adolescent populations. In addition, the evidence base supporting the therapeutic benefits of creatine supplementation for a plethora of clinical applications in both adults and children continues to grow. Among pediatric populations, a strong rationale exists for creatine to afford therapeutic benefits pertaining to multiple neuromuscular and metabolic disorders, with preliminary evidence for other subsets of clinical populations as well. Despite the strong evidence supporting the efficacy and safety of creatine supplementation among adult populations, less is known as to whether similar physiological benefits extend to children and adolescent populations, and in particular those adolescent populations who are regularly participating in high-intensity exercise training. While limited in scope, studies involving creatine supplementation and exercise performance in adolescent athletes generally report improvements in a number of ergogenic outcomes with limited evidence of ergolytic properties and consistent reports indicating no adverse events associated with supplementation. The purpose of this article is to summarize the rationale, prevalence of use, performance benefits, clinical applications, and safety of creatine use in children and adolescents.

Little is known about the optimal time to consume caffeine prior to exercise to maximize the ergogenic benefits of the substance.Purpose: To determine the optimal pre-exercise time interval to consume caffeine to improve lower-body muscular performance. A secondary aim was to identify the presence of any sex differences in responses to timed caffeine administration.Methods: Healthy, resistance-trained males (n = 18; Mean±SD; Age: 25.1 ± 5.7 years; Height: 178.4 ± 7.1 cm; Body mass: 91.3 ± 13.5 kg; Percent body fat: 20.7 ± 5.2; Average caffeine consumption: 146.6 ± 100.3 mg/day) and females (n = 11; Mean ± SD; Age: 20.1 ± 1.6 years; Height: 165.0 ± 8.8 cm; Body mass: 65.8 ± 10.0 kg; Percent bodyfat: 25.8 ± 4.2; Average caffeine consumption: 111.8 ± 91.7 mg/day) participated in this investigation. In a randomized, double-blind, placebo-controlled, crossover fashion, participants consumed 6 mg·kg−1 caffeine or placebo solution at three time points: 2 h prior (2H), 1 h prior (1H), or 30 min prior (30M) to exercise testing. During three visits, caffeine was randomly administered at one time point, and placebo was administered at the other two time points. During one visit, placebo was administered at all three time points. Next, participants performed isometric mid-thigh pulls (IMTP), countermovement vertical jumps (CMVJ), and isometric/isokinetic knee extensor testing (ISO/ISOK).Results: Caffeine administered at 1H significantly improved absolute CMVJ and ISO performance relative to placebo. Mean CMVJ jump height was significantly higher during 1H compared to 30M. However, only caffeine administered at 30M significantly improved absolute measures of isokinetic performance. Analysis of the pooled caffeine conditions revealed that muscular performance was more consistently augmented by caffeine in males compared to females.Conclusions: Pre-exercise caffeine timing significantly modulated participant responses to the substance, with 1H exerting the most consistent ergogenic benefits relative to other time points, particularly compared to 2H. Male participants were found to respond more consistently to caffeine compared to female participants. These results suggest that active individuals can maximize the ergogenic effects of caffeine by consuming the substance ~1 h prior to the point when peak muscular performance is desired.

This case study examined changes in body composition, resting metabolic rate (RMR), aerobic capacity, and daily physical activity in a patient who had ulcerative colitis and underwent ileal pouch-anal anastomosis (IPAA) surgery. Body composition, RMR, and peak oxygen consumption (VO2peak) were assessed prior to surgery and four, eight, and 16 weeks after IPAA surgery. Daily physical activity data were extracted from a wrist-worn activity tracker preoperatively and 16 months postoperatively. At baseline, total body mass was 95.3 kg; body fat, 11.6%; lean body mass, 81.1 kg; RMR, 2416 kcal/d; and VO2peak, 42.7 mL/kg/min. All values decreased from baseline at four weeks postoperatively, body mass was 85.2 kg (−10.5%); body fat, 10.9% (−6.0%); lean body mass, 73.1 kg (−9.9%); RMR 2210 kcal/d (−8.5%) and VO2peak, 25.5 mL/kg/min (−40.3%). At 16 weeks postoperatively, most parameters were near their baseline levels (within 1–7%), exceptions were VO2peak, which was 20.4% below baseline, and RMR, which increased to nearly 20% above baseline. After the patient had IPAA surgery, his total and lean body masses, RMR, and aerobic capacity were markedly decreased. Daily physical activity decreased postoperatively and likely contributed to the decreased aerobic capacity, which may take longer to recover compared to body composition and RMR parameters.

Fish oils (FOs) are rich in omega-3 long-chain polyunsaturated fatty acids, which have been purported to enhance recovery of muscular performance and reduce soreness post-exercise. However, the most effective FO dose for optimizing recovery remains unclear. The purpose of this investigation was to examine the effect of FO supplementation dosing on the recovery of measures of muscular performance, perceived soreness, and markers of muscle damage following a rigorous bout of eccentric exercise. Thirty-two college-aged resistance-trained males (~23.6 years, 71.6 kg, 172.1 cm) were supplemented with 2, 4, 6 g/day (G) FO or placebo (PL) for ~7.5 weeks. Following 7 weeks of supplementation, pre-exercise (PRE) performance assessments of vertical jump (VJ), knee extensor strength, 40-yard sprint, T-test agility, and perceived soreness were completed prior to a bout of muscle-damaging exercise and were repeated immediately post (IP), 1-, 2-, 4-, 24-, 48-, and 72-h (H) post-exercise. Repeated measures analysis of variance indicated a treatment &times, time interaction (p &lt, 0.001) for VJ and perceived soreness, but no group differences were observed at any time point. VJ returned to PRE (54.8 &plusmn, 7.9 cm) by 1H (51.8 &plusmn, 6.5 cm, p = 0.112) for 6G, while no other groups returned to baseline until 48H. Lower soreness scores were observed in 6G compared to PL at 2H (mean difference [MD] = 2.74, p = 0.046), at 24H (MD: 3.45, p &lt, 0.001), at 48H (MD = 4.45, p &lt, 0.001), and at 72H (MD = 3.00, p = 0.003). Supplementation with 6G of FO optimized the recovery of jump performance and muscle soreness following a damaging bout of exercise.

Large (48-g), isonitrogenous doses of rice and whey protein have previously been shown to stimulate similar adaptations to resistance training, but the impact of consuming smaller doses has yet to be compared. We evaluated the ability of 24-g doses of rice or whey protein concentrate to augment adaptations following 8 weeks of resistance training. Healthy resistance-trained males (n = 24, 32.8 ± 6.7 years, 179.3 ± 8.5 cm, 87.4 ± 8.5 kg, 27.2 ± 1.9 kg/m2, 27.8 ± 6.0% fat) were randomly assigned and matched according to fat-free mass to consume 24-g doses of rice (n = 12, Growing Naturals, LLC) or whey (n = 12, NutraBio Labs, Inc.) protein concentrate for 8 weeks while completing a standardized resistance training program. Body composition (DXA), muscular strength (one-repetition maximum [1RM]) and endurance (repetitions to fatigue [RTF] at 80% 1RM) using bench press (BP) and leg press (LP) exercises along with anaerobic capacity (Wingate) were assessed before and after the intervention. Subjects were asked to maintain regular dietary habits and record dietary intake every 2 weeks. Outcomes were assessed using 2 × 2 mixed (group x time) factorial ANOVA with repeated measures on time and independent samples t-tests using the change scores from baseline. A p-value of 0.05 and 95% confidence intervals on the changes between groups were used to determine outcomes. No baseline differences (p > 0.05) were found for key body composition and performance outcomes. No changes (p > 0.05) in dietary status occurred within or between groups (34 ± 4 kcal/kg/day, 3.7 ± 0.77 g/kg/day, 1.31 ± 0.28 g/kg/day, 1.87 ± 0.23 g/kg/day) throughout the study for daily relative energy (34 ± 4 kcals/kg/day), carbohydrate (3.7 ± 0.77 g/kg/day), fat (1.31 ± 0.28 g/kg/day), and protein (1.87 ± 0.23 g/kg/day) intake. Significant main effects for time were revealed for body mass (p = 0.02), total body water (p = 0.01), lean mass (p = 0.008), fat-free mass (p = 0.007), BP 1RM (p = 0.02), BP volume (p = 0.04), and LP 1RM (p = 0.01). Changes between groups were similar for body mass (− 0.88, 2.03 kg, p = 0.42), fat-free mass (− 0.68, 1.99 kg, p = 0.32), lean mass (− 0.73, 1.91 kg, p = 0.37), fat mass (− 0.48, 1.02 kg, p = 0.46), and % fat (− 0.63, 0.71%, p = 0.90). No significant between group differences were seen for BP 1RM (− 13.8, 7.1 kg, p = 0.51), LP 1RM (− 38.8, 49.6 kg, p = 0.80), BP RTF (− 2.02, 0.35 reps, p = 0.16), LP RTF (− 1.7, 3.3 reps, p = 0.50), and Wingate peak power (− 72.5, 53.4 watts, p = 0.76) following the eight-week supplementation period. Eight weeks of daily isonitrogenous 24-g doses of rice or whey protein in combination with an eight-week resistance training program led to similar changes in body composition and performance outcomes. Retroactively registered on as NCT04411173 .

Dolan, P, Witherbee, KE, Peterson, KM, and Kerksick, CM. Effect of carbohydrate, caffeine, and carbohydrate + caffeine mouth rinsing on intermittent running performance in collegiate male lacrosse athletes. J Strength Cond Res 31(9): 2473-2479, 2017-Recently, an interest has developed in the potential to rinse the oral cavity with key nutrients to impact various types of exercise and presumably sporting performance. Although multiple studies examining carbohydrate mouth rinsing have been completed, conflicting evidence surrounding caffeine mouth rinsing persists, and no research has explored its ability to impact high-intensity, intermittent running performance. This study investigated the independent and synergistic ability of carbohydrate and caffeine mouth rinsing to improve intermittent running performance. The Yo-Yo Intermittent Recovery Test-Level 1 (Yo-Yo Level 1) was completed in 10 collegiate (National Collegiate Athletic Association [NCAA] Division II) male lacrosse players after a 10-second mouth rinse with a solution of either carbohydrate (CHO), caffeine (CAF), carbohydrate + caffeine (CHO + CAF), placebo (H2O), or a no rinse control (CON). No significant improvements in Yo-Yo IRT-1 performance were found (p > 0.05). Perceptual indications of effort (i.e., rating of their perceived exertion [RPE]) were significantly lower (p ≤ 0.05) in CHO and CHO + CAF when compared with CON after speed level 11. Interestingly, RPE levels were nonsignificantly lower in all but one level of the Yo-Yo Level 1 for CHO in comparison with other groups. Carbohydrate and caffeine mouth rinsing seems to exert no impact on running performance before maximal intermittent running in a group of male collegiate lacrosse players.

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 &plusmn, SD, Age: 21.0 &plusmn, 1.8 years, Height: 179 &plusmn, 6.3 cm, Body Mass: 91.8 &plusmn, 13.3 kg, % Body Fat: 21.3 &plusmn, 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 &times, 2 (group &times, 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 &gt, 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.

Harty, PS, Zabriskie, HA, Stecker, RA, Currier, BS, Moon, JM, Richmond, SR, Jagim, AR, and Kerksick, CM. Position-specific body composition values in female collegiate rugby union athletes. J Strength Cond Res XX(X): 000-000, 2019-Rugby union is a full-contact, intermittent team sport. Anthropometric characteristics of rugby union athletes have been shown to influence suitability for a given position and affect performance. However, little anthropometric data exist in female rugby union athletes. Thus, the purpose of this study was to report position-specific anthropometric, body composition, and bone density values in female collegiate rugby union athletes and to identify between-position differences in these variables. This investigation was a cross-sectional study involving 101 female collegiate rugby union athletes, categorized as forwards and backs as well as by position (props, hookers, locks, flankers, number 8 forwards, halfback, fly-half, centers, wings, and fullbacks). Anthropometric characteristics of all athletes were measured, and body composition was assessed via dual-energy x-ray absorptiometry. Outcome variables included age, height, body mass, BMI, body fat percentage, fat mass (FM), FM index, fat-free mass (FFM), FFM index, lean soft tissue, bone mineral content, bone mineral area, and bone mineral density. Anthropometric and body composition differences between forwards and backs were identified via independent t-tests and Mann-Whitney U tests, depending on normality of the variable. Between-position differences were assessed using one-way analysis of variances (ANOVAs) with Tukey post-hoc comparisons or Welch's ANOVA with Dunnett's T3 post-hoc test. Significant differences (p < 0.014) were identified between forwards and backs for every anthropometric variable, with forwards displaying greater height (167.7 ± 7.2 cm), body mass (81.5 ± 15.1 kg), and body fat percentage (28.2 ± 6.1%) relative to backs (164.5 ± 5.1 cm; 64.5 ± 7.7 kg; 21.9 ± 3.7%). Likewise, significant differences were identified for every anthropometric variable between several positions (p < 0.01). Significant (p < 0.05) interposition differences were identified within the subgroup of forwards, but not within the subgroup of backs. The present investigation is the first to report position-specific anthropometric and body composition data in female collegiate rugby union athletes. The results of this study can be used by rugby union coaches for recruiting and personnel decisions, to determine a player's suitability for a given position, and to further inform training and nutritional interventions in this population.

Little data is available regarding the energy and nutritional status of female collegiate team sport athletes. Twenty female NCAA Division II lacrosse athletes (mean &plusmn, SD: 20.4 &plusmn, 1.8 years, 68.8 &plusmn, 8.9 kg, 168.4 &plusmn, 6.6 cm, 27.9 &plusmn, 3% body fat) recorded dietary intake and wore a physical activity monitor over four consecutive days at five different time points (20 days total) during one academic year. Body composition, bone health, and resting metabolic rate were assessed in conjunction with wearing the monitor during off-season, pre-season, and season-play. Body fat percentage decreased slightly during the course of this study (p = 0.037). Total daily energy expenditure (TDEE) (p &lt, 0.001) and activity energy expenditure (AEE) (p = 0.001) energy were found to change significantly over the course of the year, with pre-season training resulting in the highest energy expenditures (TDEE: 2789 &plusmn, 391 kcal/day, AEE: 1001 &plusmn, 267 kcal/day). Caloric (2124 &plusmn, 448 kcal/day), carbohydrate (3.6 &plusmn, 1.1 g/kg), and protein (1.2 &plusmn, 0.3 g/kg) intake did not change over the course of the year (p &gt, 0.05). Athletes self-reported a moderate negative energy balance (366&ndash, 719 kcal/day) and low energy availability (22.9&ndash, 30.4 kcal/kg FFM) at each measurement period throughout the study. Reported caloric and macronutrient intake was low given the recorded energy expenditure and macronutrient intake recommendations for athletes. Athletic support staff should provide athletes with appropriate fueling strategies, particularly during pre-season training, to adequately meet energy demands.

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.

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

Owing to the increased physical demand that results from high volumes of intense exercise training, the daily requirements for energy and carbohydrates and protein are greater in athletes than in sedentary individuals. To date, much research has been published that outlines nutrient intake recommendations for different types athletes, which highlights key differences that occur with gender as well as the modality, intensity, and duration of exercise. Understanding that optimal nutrient composition is important for athletes and coaches because of the impact diet can play on nutrient utilization during exercise as well as in the recovery of exercise. Effective manipulation of these requirements can facilitate and optimize training adaptations while also preventing untoward physiological changes from consuming either too much or too little of the macronutrients. This chapter will present key scientific evidence to outline the optimal nutrient composition for carbohydrates, protein, and fat intake for endurance as well as strength and power athletes.

Milk and dairy products are known to contain various bioactives with potential anti-inflammatory and immune modulating effects. Previous research has indicated that milk produced from hyperimmunized cows provided meaningful health benefits to individuals suffering from varying degrees of osteoarthritis and rheumatoid arthritis. PURPOSE: To examine the impact of MicroLactin&reg, a proprietary milk protein concentrate, on joint discomfort and physical function, exercise performance, quality of life and various measures of affect. METHODS: Non-osteoarthritic men (42.5 &plusmn, 8.9 years, 176.7 &plusmn, 6.7 cm, 89.9 &plusmn, 11.5 kg, 28.8 &plusmn, 3.5 kg/m2, n = 30) and women (46.4 &plusmn, 9.6 years, 163.1 &plusmn, 8.2 cm, 72.2 &plusmn, 13.1 kg, 27.2 &plusmn, 5.3 kg/m2, n = 28) with mild to moderate knee pain during physical activity were randomized in a double-blind, placebo-controlled fashion to consume daily either a placebo (PLA) or MicroLactin&reg, (ML) for a period of 8 weeks. Participants completed a functional capacity test pre and post-supplementation and completed visual analog scales (VAS), a 6-min walking test, WOMAC and profile of mood states (POMS) to assess changes in joint health, discomfort, physical function, exercise performance and affect. Mixed factorial ANOVA was used for all statistical analysis and significance was set a priori at p &le, 0.05. RESULTS: Distance covered in the 6-min walking significantly improved 9% in ML versus 2% in PLA (mean difference: 110 &plusmn, 43 m, p = 0.012) in addition to 11 WOMAC components and 5 VAS reflective of ML improving joint health, discomfort and joint stability (all p &lt, 0.05 vs. PLA). Additionally, ML also improved overall perceptions of neck and back health compared to PLA. Serum and whole blood indicators of clinical safety remained within normal ranges throughout the study. CONCLUSIONS: In comparison to placebo, daily doses of MicroLactin&reg, yielded improvements in several components of the WOMAC, multiple visual analog scales indicative of joint health and stability, discomfort and pain, as well as significant improvements in distance covered during a 6-min walking test. Supplementation was well tolerated with no significant changes in whole-blood or serum markers of clinical safety.

Energy needs of female team-sport athletes are poorly understood with no evidence highlighting differences present between scheduled activities. The purpose of this study was to examine the difference in energy expenditure between NCAA Division II female basketball (BBALL) and lacrosse (LAX) athletes during different scheduled team activities. Female BBALL (n = 13, 19.8 ± 1.3 yrs, 173.9 ± 13.6 cm, 74.6 ± 9.1kg, 27.1 ± 3.2%fat) and LAX (n = 20, 20.4 ± 1.8yrs, 168.4 ± 6.6cm, 68.8 ± 8.9kg, 27.9 ± 3.1%fat) athletes were outfitted with heart rate and activity monitors during four consecutive days on five different occasions (20 days total) across an entire academic year to assess differences in total daily activity energy expenditure (TDEE), activity energy expenditure (AEE), and physical activity level (PAL). Data were categorized by type of scheduled daily activities: Practice, Game, Conditioning, or Off. Independent of day type, TDEE, AEE, and PAL levels were greater (p &lt, 0.05) in BBALL athletes. For each sport, TDEE, AEE, and PAL were significantly different (p &lt, 0.05) between classified activity days. BBALL and LAX athletes experienced higher values on game days for TDEE, AEE, and PAL, with the lowest values experienced on off days. In conclusion, calculated levels of TDEE, AEE, and PAL in female collegiate BBALL and LAX athletes were determined to be different, irrespective of the scheduled activity.

Adenosine triphosphate (ATP) is the primary compound that provides energy to drive many processes in living cells, including muscle contraction, neurotransmission, and cardiac function. Initial research used enteric-coated ATP that displayed no apparent efficacy. However, ATP disodium supplementation has demonstrated improved bioavailability and acute and chronic benefits to cardiovascular health, muscular performance, body composition, and recovery while attenuating muscle breakdown and fatigue. In this review, we provide a critical assessment of oral ATP’s bioavailability and its various health and ergogenic benefits.

Substantial research has been completed examining the impact of carbohydrate (CHO) intake on endurance exercise, whereas its role in resistance-based exercise performance, adaptation and cell signalling has yet to be fully characterised. This empirical shortcoming has precluded the ability to establish specific CHO recommendations for resistance exercise. This results in recommendations largely stemming from findings based on endurance exercise and/or anecdotal evidence despite the distinct energetic demands and molecular responses mediating adaptation from endurance- and resistance-based exercise. Moreover, the topic of CHO and exercise has become one of polarising nature with divergent views – some substantiated, others lacking evidence. Current literature suggests a moderately high daily CHO intake (3–7 g/kg per d) for resistance training, which is thought to prevent glycogen depletion and facilitate performance and adaptation. However, contemporary investigation, along with an emerging understanding of the molecular underpinnings of resistance exercise adaptation, may suggest that such an intake may not be necessary. In addition to the low likelihood of true glycogen depletion occurring in response to resistance exercise, a diet restrictive in CHO may not be detrimental to acute resistance exercise performance or the cellular signalling activity responsible for adaptation, even when muscle glycogen stores are reduced. Current evidence suggests that signalling of the mammalian target of rapamycin complex 1, the key regulatory kinase for gene translation (protein synthesis), is unaffected by CHO restriction or low muscular glycogen concentrations. Such findings may call into question the current view and subsequent recommendations of CHO intake with regard to resistance-based exercise.

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 w...

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.

Aerobic exercise and thermal stress instigate robust challenges to the immune system. Various attempts to modify or supplement the diet have been proposed to bolster the immune system responses. The purpose of this study was to identify the impact of yeast beta-glucan (Saccharomyces cerevisiae) supplementation on exercise-induced muscle damage and inflammation. Healthy, active men (29.6 &plusmn, 6.7 years, 178.1 &plusmn, 7.2 cm, 83.2 &plusmn, 11.2 kg, 49.6 &plusmn, 5.1 mL/kg/min, n = 16) and women (30.1 &plusmn, 8.9 years, 165.6 &plusmn, 4.1 cm, 66.7 &plusmn, 10.0 kg, 38.7 &plusmn, 5.8 mL/kg/min, n = 15) were randomly assigned in a double-blind and cross-over fashion to supplement for 13 days with either 250 mg/day of yeast beta-glucan (YBG) or a maltodextrin placebo (PLA). Participants arrived fasted and completed a bout of treadmill exercise at 55% peak aerobic capacity (VO2Peak) in a hot (37.2 &plusmn, 1.8 &deg, C) and humid (45.2 &plusmn, 8.8%) environment. Prior to and 0, 2, and 72 h after completing exercise, changes in white blood cell counts, pro- and anti-inflammatory cytokines, markers of muscle damage, markers of muscle function, soreness, and profile of mood states (POMS) were assessed. In response to exercise and heat, both groups experienced significant increases in white blood cell counts, plasma creatine kinase and myoglobin, and soreness along with reductions in peak torque and total work with no between-group differences. Concentrations of serum pro-inflammatory cytokines in YBG were lower than PLA for macrophage inflammatory protein 1&beta, (MIP-1&beta, ) (p = 0.044) and tended to be lower for interleukin 8 (IL-8) (p = 0.079), monocyte chemoattractment protein 1 (MCP-1) (p = 0.095), and tumor necrosis factor &alpha, (TNF-&alpha, ) (p = 0.085). Paired samples t-tests using delta values between baseline and 72 h post-exercise revealed significant differences between groups for IL-8 (p = 0.044, 95% Confidence Interval (CI): (0.013, 0.938, d = &minus, 0.34), MCP-1 (p = 0.038, 95% CI: 0.087, 2.942, d = &minus, 0.33), and MIP-1&beta, (p = 0.010, 95% CI: 0.13, 0.85, d = &minus, 0.33). POMS outcomes changed across time with anger scores in PLA exhibiting a sharper decline than YBG (p = 0.04). Vigor scores (p = 0.04) in YBG remained stable while scores in PLA were significantly reduced 72 h after exercise. In conclusion, a 13-day prophylactic period of supplementation with 250 mg of yeast-derived beta-glucans invoked favorable changes in cytokine markers of inflammation after completing a prolonged bout of heated treadmill exercise.

Creatine has been extensively researched and is well-supported as one of the most effective dietary supplements available. There is overwhelming support within the literature regarding the ability of creatine to augment performance following short term (5–7 days) and long-duration supplementation periods. There is also strong support for creatine regarding its safety profile and minimal risk for adverse events or any negative influence on markers of clinical health and safety. Recent research has also highlighted the ability of creatine to confer several health-related benefits in select clinical populations in addition to offering cognitive benefits. Creatine is also a popular supplement of choice for adolescent athletes; however, research in this area is extremely limited, particularly when examining the safety and efficacy of creatine supplementation in this population. Therefore, the purpose of this review was to highlight the limited number of studies available in adolescent populations and systematically discuss the topic of safety of creatine supplementation in a younger population.

This study investigated the effect of branched-chain amino acid (BCAA) supplementation on recovery from eccentric exercise. Twenty males ingested either a BCAA supplement or placebo (PLCB) prior to and following eccentric exercise. Creatine kinase (CK), vertical jump (VJ), maximal voluntary isometric contraction (MVIC), jump squat (JS) and perceived soreness were assessed. No significant (p &gt, 0.05) group by time interaction effects were observed for CK, soreness, MVIC, VJ, or JS. CK concentrations were elevated above baseline (p &lt, 0.001) in both groups at 4, 24, 48 and 72 hr, while CK was lower (p = 0.02) in the BCAA group at 48 hr compared to PLCB. Soreness increased significantly from baseline (p &lt, 0.01) in both groups at all time-points, however, BCAA supplemented individuals reported less soreness (p &lt, 0.01) at the 48 and 72 hr time-points. MVIC force output returned to baseline levels (p &gt, 0.05) at 24, 48 and 72 hr for BCAA individuals. No significant difference between groups (p &gt, 0.05) was detected for VJ or JS. BCAA supplementation may mitigate muscle soreness following muscle-damaging exercise. However, when consumed with a diet consisting of ~1.2 g/kg/day protein, the attenuation of muscular performance decrements or corresponding plasma CK levels are likely negligible.

Zanders, BR, Currier, BS, Harty, PS, Zabriskie, HA, Smith, CR, Stecker, RA, Richmond, SR, Jagim, AR, and Kerksick, CM. Changes in energy expenditure, dietary intake, and energy availability across an entire collegiate women's basketball season. J Strength Cond Res 35(3): 804-810, 2021-The purpose of this study was to identify changes in energy expenditure and dietary intake across an entire women's basketball season. On 5 different occasions across the competitive season, female collegiate basketball players (19.8 ± 1.3 years, 173.9 ± 13.6 cm, 74.6 ± 9.1 kg, 27.1 ± 3.2% fat, 53.9 ± 6.4 ml·kg-1·min-1, n = 13) were outfitted with heart rate and activity monitors over 4 consecutive days and completed 4-day food and fluid records to assess changes in energy expenditure and dietary status. Dual-energy x-ray absorptiometry was used to assess baseline body composition and resting energy expenditure (REE) was measured before and after the season. Data were analyzed using 1-factor repeated-measures analysis of variance. Total daily energy expenditure (TDEE, p = 0.059) and physical activity levels (TDEE/REE, p = 0.060) both tended to decrease throughout the season. Energy balance was negative at all time points throughout the season. Absolute and normalized daily protein intake at the end of the season was significantly (p0.05) lower than at the beginning of the season. Carbohydrate (3.7 ± 0.4 g·kg-1·d-1) and protein (1.17 ± 0.16 g·kg-1·d-1) intakes were lower than commonly recommended values based on previously published guidelines. These findings suggest that greater education and interventions for collegiate athletes and coaches regarding dietary intake and energy expenditure are warranted.

BACKGROUND: Augmenting fat oxidation is a primary goal of fitness enthusiasts and individuals desiring to improve their body composition. Performing aerobic exercise while fasted continues to be a popular strategy to achieve this outcome, yet little research has examined how nutritional manipulations influence energy expenditure and/or fat oxidation during and after exercise. Initial research has indicated that pre-exercise protein feeding may facilitate fat oxidation while minimizing protein degradation during exercise, but more research is needed to determine if the source of protein further influences such outcomes. METHODS: Eleven healthy, college-aged males (23.5 ± 2.1 years, 86.0 ± 15.6 kg, 184 ± 10.3 cm, 19.7 ± 4.4%fat) completed four testing sessions in a randomized, counter-balanced, crossover fashion after observing an 8–10 h fast. During each visit, baseline substrate oxidation and resting energy expenditure (REE) were assessed via indirect calorimetry. Participants ingested isovolumetric, solutions containing 25 g of whey protein isolate (WPI), 25 g of casein protein (CAS), 25 g of maltodextrin (MAL), or non-caloric control (CON). After 30 min, participants performed 30 min of treadmill exercise at 55–60% heart rate reserve. Substrate oxidation and energy expenditure were re-assessed during exercise and 15 min after exercise. RESULTS: Delta scores comparing the change in REE were normalized to body mass and a significant group x time interaction (p = 0.002) was found. Post-hoc comparisons indicated the within-group changes in REE following consumption of WPI (3.41 ± 1.63 kcal/kg) and CAS (3.39 ± 0.82 kcal/kg) were significantly greater (p

This study investigated the effect of creatine (CR) supplementation during cast-immobilization to preserve skeletal muscle total work, power and intramuscular phosphocreatine (PCr) kinetics during dynamic exercise.Twenty-five active individuals (24 ± 4 years,) performed wrist flexion exercise within a 1.9 Tesla superconducting magnet before and after 1 week of cast-immobilization. An incremental protocol to fatigue and two constant load (CL1 and CL2) exercise bouts were performed. While casted, participants consumed either 20 g day(-1) of CR or a placebo (PLA). (31)P magnetic resonance spectroscopy was used to quantify in vivo intramuscular PCr levels.No significant group × time interaction effects were found for work or power throughout all exercise bouts. Total work was significantly reduced over time in both groups (p = 0.049) during the incremental exercise bout. Work production in CL1 tended (p = 0.073) to attenuate in the CR group, compared to PLA. No changes were observed in CL2. Baseline PCr significantly decreased with casting in PLA (PRE: 26.6 ± 6.3 vs. POST: 22.5 ± 5.6 mM kg(-1) wet muscle, p = 0.003). No change (p = 0.31) was observed in the CR group. Changes in work production were significantly correlated with changes in resting PCr in CR (r = -0.63, p = 0.021) but not PLA (r = -0.36, p = 0.26) group.Results suggest decreases in short-term endurance may be due to alternations of PCr status and/or metabolism. More research is needed to fully determine the efficacy of CR supplementation during short-term immobilization.

PROTEIN, A KEY MACRONUTRIENT, IS NEEDED BY THE BODY TO REPAIR AND BUILD NEW CELLULAR STRUCTURES. EXERCISING INDIVIDUALS PARTICIPATING IN BOTH AEROBIC AND ANAEROBIC ACTIVITIES REQUIRE GREATER AMOUNTS OF PROTEIN (1.2–1.6 G·KG−1·D−1) IN THEIR DIET. PROTEIN QUALITY IS EVALUATED PRIMARILY BY ESSE

Objective The aim of this study was to investigate the effects of ingesting caffeine and green coffee bean extract on blood glucose and insulin concentrations during a post-exercise oral glucose tolerance test. Methods Ten male cyclists (age: 26 ± 5 y; height: 179.9 ± 5.4 cm; weight: 77.6 ± 13.3 kg; body mass index: 24 ± 4.3 kg/m 2 ; VO 2 peak: 55.9 ± 8.4 mL·kg·min −1 ) participated in this study. In a randomized order, each participant completed three 30-min bouts of cycling at 60% of peak power output. Immediately after exercise, each participant consumed 75 g of dextrose with either 5 mg/kg body weight of caffeine, 10 mg/kg of green coffee bean extract (5 mg/kg chlorogenic acid), or placebo. Venous blood samples were collected immediately before and after exercise during completion of the oral glucose tolerance test. Results No significant time × treatment effects for blood glucose and insulin were found. Two-h glucose and insulin area under the curve values, respectively, for the caffeine (658 ± 74 mmol/L and 30,005 ± 13,304 pmol/L), green coffee bean extract (637 ± 100 mmol/L and 31,965 ± 23,586 pmol/L), and placebo (661 ± 77 mmol/L and 27,020 ± 12,339 pmol/L) trials were not significantly different ( P > 0.05). Conclusion Caffeine and green coffee bean extract did not significantly alter postexercise blood glucose and insulin concentrations when compared with a placebo. More human research is needed to determine the impact of these combined nutritional treatments and exercise on changes in blood glucose and insulin.

ECCENTRIC TRAINING AND ECCENTRIC MUSCULAR CONTRACTIONS FOCUS ON ACTIVE LENGTHENING WHILE LOADED. WHEN COMPARED WITH CONCENTRIC MOVEMENTS, ECCENTRIC ACTIONS YIELD GREATER FORCE LEVELS WITH CONCOMITANT LOWER NEUROMUSCULAR ACTIVATION LEVELS. ECCENTRIC TRAINING IS MAINLY INCORPORATED INDIRECTLY

The factors that best account for differences in strength across all types of exercise, body types, and training histories are not well understood. The purpose of this study was to assess the effects of strength level and body composition on upper- and lower-body work capacity in adult men. From a cohort of 295 adult men (25.6 ± 7.5 years, 178 ± 8 cm, 85.2 ± 15 kg), low-strength (LS, n = 72) and high-strength (HS, n = 66) samples were selected based on 1 repetition maximum (1RM) bench press (BP) and leg strength (LP) values. Work capacity for each exercise was determined from the product of repetition weight (80% 1RM) and maximum repetitions-to-fatigue (RTF). Body composition was measured using dual-energy x-ray absorptiometry. The HS group was significantly greater than the LS group in total body mass and fat-free mass but not in age, height, fat mass, or %fat. Low-strength and HS groups were not significantly different (p > 0.05) in RTF for either BP (8.7 ± 3.1 vs. 8.3 ± 1.9 reps, respectively) or LP (15.6 ± 7.6 vs. 17.0 ± 6.3 reps, respectively), making the ratio of RTF for BP vs. LP nonsignificant (LS = 2.0 ± 1.0; HS = 2.2 ± 0.9). The HS group produced significantly greater (p < 0.001) absolute and relative work capacities for both BP and LP compared with the LS group. Repetitions-to-fatigue had a greater influence on BP (r2 = 0.74) and LP (r2 = 0.85) work capacities in the LS group than did RepWt (r2 = 0.07 and 0.28, respectively). In the HS group, RTF (r2 = 0.79) had a greater influence than RepWt (r2 = 0.10) on BP work capacity, whereas the 2 components were more similar for LP work capacity (r2 = 0.64 and 0.47, respectively). When evaluated at the same %1RM, muscular endurance is similar across divergent strength levels meaning that work capacity (load × reps) will be greater for HS individuals. Controlling for the influence of body composition variables (e.g., fat or fat-free mass) does not eliminate the difference in work capacity between strength groups suggesting that other factors are accounting for strength expression. Prescribing repetitions against a fixed relative load is largely dependent on exercise type and must be considered by strength and conditioning professionals.

Background: It is known that unaccustomed exercise&mdash, especially when it has an eccentric component&mdash, 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 &plusmn, 2 y, 70.0 &plusmn, 13.7 kg, 169.3 &plusmn, 15.2 cm, 25.6 &plusmn, 14.3 body mass index (BMI), 32 women, 31 men) were randomly assigned to ingest 250 mg of CurcuWIN&reg, (50 mg of curcuminoids), 1000 mg of CurcuWIN&reg, (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.

The purpose of this study was to investigate how age and 1 week of conventional resistance exercise affects commonly used housekeeping gene (HKG) messenger RNAs (mRNAs) in skeletal muscle. Ten college-aged (18�25 years) and 10 older (60�76 years) men completed 3 lower-body resistance exercise bouts on Monday, Wednesday, and Friday, and muscle samples were obtained before bout 1 (T1), 48 hours after the first (T2) and second bouts (T3), and 24 hours after the third bout (T4). Raw Ct values indicated that [beta]-actin and cyclophilin were more highly expressed in older vs. younger males (p < 0.01) at T1. When normalizing each HKG mRNA to the other 4 HKG mRNAs, CYC increased at T3 and glyceraldehyde-3-phosphate dehydrogenase decreased at T2 (p < 0.05) in younger men. This is one of the few studies to suggest that explicit HKG mRNAs should be used depending upon age group and resistance exercise intervention.

P1 Impact of antioxidant-enriched nutrient bar supplementation on the serum antioxidant markers and physical fitness components of track and field athletes