The Effects of Leucine-Enriched Branched-Chain Amino Acid Supplementation on Recovery After High-Intensity Resistance Exercise.

CONTEXT: Of the 3 branched-chain amino acids (BCAA), leucine has arguably received the most attribution for the role of BCAA supplementation in alleviating symptoms of exercise-induced muscle damage and facilitation of acute performance recovery. PURPOSE: To examine whether enrichment of a standard BCAA supplement with additional leucine or a standalone leucine (LEU) supplement differentially affects exercise-induced muscle damage and performance recovery compared with a standard BCAA supplement. METHODS: A total of 22 recreationally active male and female subjects were recruited and assigned to consume a BCAA, leucine-enriched BCAA (LBCAA), or LEU supplement for 11 d. On the eighth day, subjects performed eccentric-based resistance exercise (ECRE). Lower-body mean average and peak power, plasma creatine kinase, soreness, and pain threshold were measured before and 24, 48, and 72 h after ECRE. RESULTS: LEU showed decreased mean average power (P = .02) and mean peak power (P = .01) from baseline to 48 h post-ECRE, whereas LBCAA and BCAA only trended toward a reduction at 24 hours post-ECRE. At 48 h post-ECRE, BCAA showed greater recovery of mean peak power than LEU (P = .04). At 24 h post-ECRE, LEU demonstrated a greater increase in plasma creatine kinase from baseline than BCAA (P = .04). Area under the curve for creatine kinase was greater in LEU than BCAA (P = .02), whereas BCAA and LBCAA did not differ. Only LEU demonstrated increased soreness during rest and under muscular tension at 24 and 48 h post-ECRE (P < .05). CONCLUSIONS: LBCAA failed to afford any advantages over a standard BCAA supplement for postexercise muscle recovery, whereas a LEU supplement was comparatively ineffective.

Metabolic impact of protein feeding prior to moderate-intensity treadmill exercise in a fasted state: a pilot study.

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 < 0.05) than following consumption of MAL (1.57 ± 0.99 kcal/kg) and tended to be greater than the non-caloric control group (2.00 ± 1.91 kcal/kg, p = 0.055 vs. WPI and p = 0.061 vs. CAS). Respiratory exchange ratio following consumption of WPI and CAS significantly decreased during the post exercise period while no change was observed for the other groups. Fat oxidation during exercise was calculated and increased in all groups throughout exercise. CAS was found to oxidize significantly more fat (p < 0.05) than WPI during minutes 10-15 (CAS: 2.28 ± 0.38 g; WPI: 1.7 ± 0.60 g) and 25-30 (CAS: 3.03 ± 0.55 g; WPI: 2.24 ± 0.50 g) of the exercise bout. CONCLUSIONS: Protein consumption before fasted moderate-intensity treadmill exercise significantly increased post-exercise energy expenditure compared to maltodextrin ingestion and tended to be greater than control. Post-exercise fat oxidation was improved following protein ingestion. Throughout exercise, fasting (control) did not yield more fat oxidation versus carbohydrate or protein, while casein protein allowed for more fat oxidation than whey. These results indicate rates of energy expenditure and fat oxidation can be modulated after CAS protein consumption prior to moderate-intensity cardiovascular exercise and that fasting did not lead to more fat oxidation during or after exercise.

ISSN exercise & sports nutrition review update: research & recommendations.

BACKGROUND: Sports nutrition is a constantly evolving field with hundreds of research papers published annually. In the year 2017 alone, 2082 articles were published under the key words 'sport nutrition'. Consequently, staying current with the relevant literature is often difficult. METHODS: This paper is an ongoing update of the sports nutrition review article originally published as the lead paper to launch the Journal of the International Society of Sports Nutrition in 2004 and updated in 2010. It presents a well-referenced overview of the current state of the science related to optimization of training and performance enhancement through exercise training and nutrition. Notably, due to the accelerated pace and size at which the literature base in this research area grows, the topics discussed will focus on muscle hypertrophy and performance enhancement. As such, this paper provides an overview of: 1.) How ergogenic aids and dietary supplements are defined in terms of governmental regulation and oversight; 2.) How dietary supplements are legally regulated in the United States; 3.) How to evaluate the scientific merit of nutritional supplements; 4.) General nutritional strategies to optimize performance and enhance recovery; and, 5.) An overview of our current understanding of nutritional approaches to augment skeletal muscle hypertrophy and the potential ergogenic value of various dietary and supplemental approaches. CONCLUSIONS: This updated review is to provide ISSN members and individuals interested in sports nutrition with information that can be implemented in educational, research or practical settings and serve as a foundational basis for determining the efficacy and safety of many common sport nutrition products and their ingredients.

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

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

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).

International society of sports nutrition position stand: diets and body composition.

Position Statement: The International Society of Sports Nutrition (ISSN) bases the following position stand on a critical analysis of the literature regarding the effects of diet types (macronutrient composition; eating styles) and their influence on body composition. The ISSN has concluded the following. 1) There is a multitude of diet types and eating styles, whereby numerous subtypes fall under each major dietary archetype. 2) All body composition assessment methods have strengths and limitations. 3) Diets primarily focused on fat loss are driven by a sustained caloric deficit. The higher the baseline body fat level, the more aggressively the caloric deficit may be imposed. Slower rates of weight loss can better preserve lean mass (LM) in leaner subjects. 4) Diets focused primarily on accruing LM are driven by a sustained caloric surplus to facilitate anabolic processes and support increasing resistance-training demands. The composition and magnitude of the surplus, as well as training status of the subjects can influence the nature of the gains. 5) A wide range of dietary approaches (low-fat to low-carbohydrate/ketogenic, and all points between) can be similarly effective for improving body composition. 6) Increasing dietary protein to levels significantly beyond current recommendations for athletic populations may result in improved body composition. Higher protein intakes (2.3-3.1 g/kg FFM) may be required to maximize muscle retention in lean, resistance-trained subjects under hypocaloric conditions. Emerging research on very high protein intakes (>3 g/kg) has demonstrated that the known thermic, satiating, and LM-preserving effects of dietary protein might be amplified in resistance-training subjects. 7) The collective body of intermittent caloric restriction research demonstrates no significant advantage over daily caloric restriction for improving body composition. 8) The long-term success of a diet depends upon compliance and suppression or circumvention of mitigating factors such as adaptive thermogenesis. 9) There is a paucity of research on women and older populations, as well as a wide range of untapped permutations of feeding frequency and macronutrient distribution at various energetic balances combined with training. Behavioral and lifestyle modification strategies are still poorly researched areas of weight management.

Effects of 8 weeks of Xpand® 2X pre workout supplementation on skeletal muscle hypertrophy, lean body mass, and strength in resistance trained males.

BACKGROUND: Xpand® 2X is a proprietary blend comprised of branched chain amino acids, creatine monohydrate, beta-alanine (CarnoSyn®), quercetin, coenzymated B-vitamins, alanyl-glutamine (Sustamine®), and natural nitrate sources from pomegranate and beet root extracts purported to enhance the neuromuscular adaptations of resistance training. However to date, no long-term studies have been conducted with this supplement. The purpose of this study was to investigate the effects of a multi-ingredient performance supplement (MIPS) on skeletal muscle hypertrophy, lean body mass and lower body strength in resistance-trained males. METHODS: Twenty resistance-trained males (21.3 ± 1.9 years) were randomly assigned to consume a MIPS or a placebo of equal weight and volume (food-grade orange flavors and sweeteners) in a double-blind manner, 30 minutes prior to exercise. All subjects participated in an 8-week, 3-day per week, periodized, resistance-training program that was split-focused on multi-joint movements such as leg press, bench press, and bent-over rows. Ultrasonography measured muscle thickness of the quadriceps, dual-energy X-ray absorptiometry (DEXA) determined lean body mass, and strength of the bench press and leg press were determined at weeks 0, 4, and 8 of the study. Data were analyzed with a 2 × 3 repeated measures ANOVA with LSD post hoc tests utilized to locate differences. RESULTS: There was a significant group-by-time interaction in which the MIPS supplementation resulted in a significant (p < 0.01) increase in strength of the bench press (18.4% vs. 9.6%) compared with placebo after 4 and 8 weeks of training. There were no significant group by time interactions between MIPS supplementation nor the placebo in leg press strength (p = .08). MIPS supplementation also resulted in a significant increase in lean body mass (7.8% vs. 3.6%) and quadriceps muscle thickness (11.8% vs. 4.5%) compared with placebo (group*time, p <0.01). CONCLUSIONS: These results suggest that this MIPS can positively augment adaptations in strength, and skeletal muscle hypertrophy in resistance-trained men.

Relationships between the Nevada brief cognitive assessment instrument and the St. Louis University mental status examination in the assessment of disability applicants.

Mental status examinations of individuals applying for disability are most often authorized as "2-hour" evaluations and are to include a complete clinical and employment history, assessment of neurocognitive functions, an estimate of general level of intelligence, psychological and social adjustment, functional abilities, and a complete multipage report of the results. In the interest of meeting these demands we have been using the Nevada brief cognitive assessment instrument (NBCAI) to rapidly estimate verbal intelligence, and we have adopted the Saint Louis University Mental Status Examination (SLUMS) to investigate neurocognitive functions. Areas of correspondence and differences between these screens are presented along with an explanation of why execution of both screens could be useful in addressing psychological questions concerning disability. The two instruments failed to correlate significantly in a group of patients undergoing pre-surgical evaluation likely because this sample was more highly educated and more homogeneous than the sample of disability referrals. For example, although the ages of the samples were close (disability sample mean and standard deviation age: 43.88 and 11.35 years; pre-surgical sample mean and standard deviation age: 46.14 and 2.84 years), they differed considerably in level of education (disability sample mean and standard deviation: 11.03 and 2.15; pre-surgical mean and standard deviation: 15.22 and 2.84). The pre-surgical group had mean performances close to the ceiling levels of both instruments.

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

Position Statement: The position of The Society regarding caffeine supplementation and sport performance is summarized by the following seven points: 1.) Caffeine is effective for enhancing sport performance in trained athletes when consumed in low-to-moderate dosages (~3-6 mg/kg) and overall does not result in further enhancement in performance when consumed in higher dosages (>/= 9 mg/kg). 2.) Caffeine exerts a greater ergogenic effect when consumed in an anhydrous state as compared to coffee. 3.) It has been shown that caffeine can enhance vigilance during bouts of extended exhaustive exercise, as well as periods of sustained sleep deprivation. 4.) Caffeine is ergogenic for sustained maximal endurance exercise, and has been shown to be highly effective for time-trial performance. 5.) Caffeine supplementation is beneficial for high-intensity exercise, including team sports such as soccer and rugby, both of which are categorized by intermittent activity within a period of prolonged duration. 6.) The literature is equivocal when considering the effects of caffeine supplementation on strength-power performance, and additional research in this area is warranted. 7.) The scientific literature does not support caffeine-induced diuresis during exercise, or any harmful change in fluid balance that would negatively affect performance.

Urine specific gravity in exercisers prior to physical training.

Urine specific gravity (USG) is used as an index of hydration status. Many studies have used USG to estimate pre-exercise hydration in athletes. However, very little is known about the pre-exercise hydration status of recreational exercisers. The purpose of the present study was to measure the pre-exercise USG in a large sample of recreational exercisers who attended 2 different fitness centers in the United States. In addition, we wanted to determine if factors such as time of day, geographic location, and gender influenced USG. We tested 166 subjects in Chicago and 163 subjects in Los Angeles. Subjects completed a survey on their typical training regimen and fluid-replacement habits, and thereafter voided and delivered a urine sample to the investigators prior to beginning exercise. Samples were measured on site for USG using a hand-held refractometer. The mean (SD) USG was 1.018 (+/- 0.007) for all subjects. Males had a higher average USG (1.020 +/- 0.007) when compared with females (1.017 +/- 0.008; p = 0.001). Despite differences in climate, no difference in mean USG occurred based on location or time of day. Based on standards used for athletes (USG > or = 1.020), 46% of the exercisers were likely to be dehydrated.

Conjugated linoleic Acid supplementation does not reduce visceral adipose tissue in middle-aged men engaged in a resistance-training program.

Conjugated linoleic acid (CLA) supplementation has shown convincing effects at reducing body fat in animals; yet human study results have been somewhat inconclusive. The purpose of this study is to determine whether four weeks of CLA supplementation, the approximate length of a commercial package, can result in a positive change in visceral adipose tissue in resistance-trained middle-aged men. Thirty overweight and moderately obese, but otherwise healthy male subjects (aged 35 to 55 years) currently involved in resistance training, were randomly assigned into CLA and placebo groups in a double-blind, placebo controlled approach. The study lasted for 12 weeks and consisted of three four-week periods. During the first four weeks (run-in period) each subject received placebo (4 g safflower oil). Throughout the next four weeks (supplementation period), the placebo group continued receiving placebo, while the CLA group received 3.2 g/d of CLA. During the final four weeks (run-out period) all subjects received the placebo. Computed tomography (CT) scans were used to measure visceral adipose tissue (VAT) at weeks 4, 8 and 12. No significant reduction in VAT cross-sectional area was determined in the CLA group during the study. On the contrary, a significant reduction in cross-sectional area of VAT of 23.12 cm2 during the supplementation period was measured in the placebo group, which was abated during the run-out period. Our results suggest that CLA supplementation of 3.2 g/d for four weeks does not promote decreases in VAT in middle-aged men currently participating in a resistance-training program.

Meat diets and fragile bones: inferences about osteoporosis.

Because women supplemented with copper have improved bone density and femurs of rats deficient in copper have decreased mechanical strength, the hypothesis that mice fed meat would have fragile bones was tested. Mice fed sirloin are hypercholesterolemic in comparison to mice fed meat and beef liver because of a relative deficiency of copper compared to zinc. Male, albino, Swiss mice were fed trimmed sirloin or sirloin supplemented with beef liver (3/1 by weight). After 62 days, when hypercholesterolemia was detected, mice were killed and femurs were removed, cleaned and dried. Breaking strength was measured carefully at room temperature. The meat diet produced femurs 23% weaker (8.8 +/- 0.70 N/mg.100 vs 11.4 +/- 0.92, mean +/- SE, p < 0.04) in comparison to meat plus liver. Calcium, copper and phosphorus concentrations were unaffected but zinc was mildly elevated in the weak bones (426 +/- 17.5 pg/g vs 355 +/- 9.23, p < 0.002). These elements generally are unaltered in osteoporotic bones. Because copper deficiency produces osteoporosis in animals and people and because the Western diet often is low in copper, further tests of the hypothesis that diets low in copper contribute to osteoporosis are warranted.