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Approximately 123 documents matched your search.
  1. How to really eat like a hunter-gatherer: Why the Paleo diet is half-baked

    The article is summed up concisely: “the Paleo diet is founded more on privilege than on logic”. Many of the “rules” for the diet are based not on nutrition science but arbitrary history. It is likely that consuming a “healthy diet”, i.e. one that includes...

  2. International Society of Sports Nutrition position stand: beta-hydroxy-beta-methylbutyrate (HMB)

    HMB is a safe and effective supplement for increasing muscle size and strength and quickening recovery from intense exercise.  Daily consumption of 3 g of HMB daily in 1 g doses starting about one hour before exercise is the optimal dosing regimen at this time.

  3. Types of Protein

    Protein is composed of amino acids, and different amino acids can have drastically different properties. For example, leucine is an essential amino acid in the class of branched chain amino acids (BCAAs); it initiates a strong anabolic response. On the other hand, glycine is an amino acid that can...

  4. Protein timing and its effects on muscular hypertrophy and strength in individuals engaged in weight-training

    Learn about how protein timing affects muscular hypertrophy and strength gains for individuals engaged in resistance weight training.

  5. Protein blend ingestion following resistance exercise promotes human muscle protein synthesis

         Whey protein is often promoted for its “superior” ability to stimulate protein muscle synthesis after exercise.  However, this study shows that a protein blend with 25% soy, 25% whey, and 50% casein stimulates protein muscle synthesis to a similar...

  6. 3/4/2011 /Whey and casein labeled with L-[1-13C]leucine and muscle protein synthesis effect of resistance exercise and protein ingestion

    The combination of repeated training sessions and at least 20 g of post-workout protein has been shown to stimulate muscle protein synthesis (MPS). Protein from cow’s milk is composed mostly of whey and casein; whey is known to be absorbed and utilized more rapidly while casein is known...

  7. Nutritional regulation of muscle protein synthesis with resistance exercise: strategies to enhance anabolism

    The combination of resistance training and protein (amino acids) leads to growth of muscle volume and strength, especially when protein/amino acids are consumed immediately after exercise.

  8. Ingesting a pre-workout supplement containing caffeine, B-vitamins, amino acids, creatine, and beta-alanine before exercise delays fatigue while improving reaction time and muscular endurance

    Several ergogenic aids (compounds that enhance sports performance) have been identified as effective for most athletes. Among these ingredients are caffeine, creatine, branched chain amino acids (BCAAs), B-vitamins, and beta-alanine.

  9. 3/4/2011 /Excess leucine intake enhances muscle anabolic signaling but not net protein anabolism in young men and women

    Although all essential amino acids (EAAs) stimulate muscle protein synthesis in animal and human models, leucine has unique properties in animal models that have raised interest in leucine as a maintenance therapy for human muscle mass. Specifically, leucine stimulates the cell hypertrophy...

  10. 3/4/2011 / Effect of glycogen availability on human skeletal muscle protein turnover during exercise and recovery

     Exercise with low glycogen would increase the net negative protein balance at the whole body and skeletal muscle levels compared with the high glycogen condition and this would be primarily due to an increase in protein breakdown with an additional reduction in protein synthesis.

  11. The effect of HMB supplementation on body composition, fitness, hormonal and inflammatory mediators in elite adolescent volleyball players: a prospective randomized, double-blind, placebo-controlled study

    Athletes often begin utilizing nutritional supplements during adolescence, despite an absence of scientific evidence for efficacy and safety of many supplements in this population. Because of the rapid growth that occurs during adolescence, a solid understanding of the effects of supplements such...

  12. 3/4/2011 /Short-term recovery from prolonged exercise: exploring the potential for protein ingestion to accentuate the benefits of carbohydrate supplements

     The authors have written a comprehensive review article (19 pages) summarizing the currently available studies examining muscle glycogen resynthesis in response to ingesting varying amounts of carbohydrate during a short-term (ie, > 2 to 6 hours) recovery in humans. The main purpose of...

  13. β-Hydroxy-β-methylbutyrate free acid reduces markers of exercise-induced muscle damage and improves recovery in resistance-trained men

    Read research on (HMB), which is a supplement that has been associated with increases in muscle size, strength, along with a quickened recovery.

  14. A cluster of exertional rhabdomyolysis affecting a Division I football team

    Exertional Rhabdomyolysis Research Study: Learn about Exertional Rhabdomyolysis, how it has affected high level athletes, & how to prevent the condition.

  15. Protein supplementation augments the adaptive response of skeletal muscle to resistance-type exercise training: a meta-analysis.

    Based on results from 22 different studies, protein supplementation aided in the gain of fat free mass in participants engaged in a resistance exercise program.  Protein supplementation also augmented gains in muscle mass and muscle strength.  These effects were true for adults of all...

  16. Effects of 7 days of arginine-alpha-ketoglutarate supplementation on blood flow, plasma L-arginine, nitric oxide metabolites, and asymmetric dimethyl arginine after resistance exercise

    Despite the significant increase in plasma arginine levels, there was not a difference in the supplemented athletes versus placebo before or after the resistance exercise in regard to blood flow or other hemodynamics. Based on other literature, it is thought that a larger dose of arginine (perhaps...

  17. 5/3/2012 / Stimulation of muscle protein synthesis by whey and caseinate ingestion after resistance exercise in elderly individuals

    Consumption of whey or casein led to similar rates of muscle synthesis regardless of whether the protein was ingested before or after the workout. A key factor to note is that protein synthesis rates were only measured at 30 and 390 min postexercise and there were no measures of overall protein...

  18. Enhanced amino acid sensitivity of myofibrillar protein synthesis persists for up to 24 h after resistance exercise in young men

    Rates of protein synthesis are highest immediately after muscle-fatiguing resistance exercise with high volumes of contractile activity in conjunction with consumption of quality protein. It has been observed that protein synthesis rates remain above baseline for longer periods of time- up to...

  19. 3/4/2011 / Antioxidant activity and hepatoprotective effects of whey protein and Spirulina in rats

    Recent interest in the use of antioxidant nutritional supplements has been sparked by epidemiologic evidence suggesting that dietary antioxidants in food constituents may protect against or prevent heart disease, cancer, and the aging process. Whey protein concentrates (WPCs) derived from milk may...

  20. A low carbohydrate-protein supplement improves endurance performance in female athletes

    It has been shown that a beverage with protein (PRO) and low carbohydrate (CHO; 3% CHO + 0.75% CHO or 4.5% CHO + 1.2% PRO) is just as effective at prolonging endurance as a 6% CHO beverage. It has also been shown that a blend of carbohydrates (i.e. glucose, maltodextrin, and fructose) can be...

  21. Activation of mTOR signaling in young and old human skeletal muscle in response to combined resistance exercise and whey protein ingestion

    Nutrition, training status, and age can affect the muscle’s response to acute exercise. However, it appears that a 12 wk, routine, resistance exercise program can be equally effective in older or younger men. As long as they are consuming adequate protein and other nutrient requirements, the...

  22. HMB supplementation: clinical and athletic performance-related effects and mechanisms of action (A Review)

    β-Hydroxy-β-methylbutyrate (HMB) has become popular due to its ability to reduce the rate of muscle damage and breakdown as well as increase the rate of protein synthesis. HMB is a metabolite of the amino acid leucine and is thought to contribute to the performance-related benefits of...

  23. 3/4/2011 /Low-carbohydrate diet does not affect intramyocellular lipid concentration or insulin sensitivity in lean, physically fit men when protein intake is elevated

     There are well established pathologic associations between excess adiposity and insulin resistance. However, insulin resistance has also been shown to be a short-term, rapidly adaptive, physiologic response in lean, physically fit humans. Although the mechanisms for insulin resistance in...

  24. VO2max and ventilatory threshold of trained cyclists are not affected by 28-day L-arginine supplementation

    L-arginine supplements are marketed with claims that they can increase strength and endurance. It has been speculated that L-arginine works by virtue of its metabolic byproduct nitric oxide (NO). Indeed, chronic arginine supplementation has been shown to improve oxygen consumption (VO2) for...

  25. Effect of various ratios of carbohydrate-protein supplementation on resistance exercise-induced muscle damage

    The authors did not provide the standard deviations/errors for their data, so it is impossible to know the inter-individual variability among their participants or gauge the practical relevance in the differences.

  26. 3/4/2011 /Effects of whey protein isolate on body composition lipids insulin and glucose in overweight and obese individuals

    The health benefits associated with increased dairy intake may be attributable to the whey component of dairy proteins. This study evaluated the effects of whey protein supplementation on body composition, lipids, insulin, and glucose compared with casein and glucose (control) supplementation in...

  27. 3/4/2011 / Effects of L-carnitine on oxidative stress responses in patients with renal disease

    Hemodialysis of patients with end-stage renal disease (ESRD) may deplete L-carnitine, an antioxidant that also functions in fat metabolism, potentially contributing to increased morbidity, mortality, and reduced quality of life. Although regular exercise is beneficial in patients with ESRD,...

  28. 3/4/2011 / Cocoa-based protein and carbohydrate drink decreases perceived soreness after exhaustive aerobic exercise: a pragmatic preliminary analysis

    A cocoa-based protein and carbohydrate prototype drink would decrease skeletal muscle cell and inflammatory biomarkers and perceived soreness compared with water. It was also hypothesized that consuming the test drink before exercise would further reduce oxidative stress biomarkers and perceived...

  29. The effect of acute taurine ingestion on 3-km running performance in trained middle-distance runners

    Ingestion of a 1,000 mg (1 g) dose of taurine two hours before running increased performance on a 3-km time trial in competitive athletes. Taurine supplementation did not affect respiratory parameters, heart rate, or blood lactate concentrations, therefore the mechanism by which taurine provides...

  30. Impact of protein coingestion on muscle protein synthesis during continuous endurance type exercise

    This study showed that the addition of protein to carbohydrate (isocaloric treatments) did not further increase mixed muscle FSR during exercise. However, it did appear, from Figure 5 in the paper, that there may have been a trend toward a greater increase in mixed muscle FSR, albeit not...

  31. 3/4/2011 /Effect of milk protein addition to a carbohydrate-electrolyte rehydration solution ingested after exercise in the heat

     During exercise, sweat losses exceeding fluid intake result in a hypohydrated state. Restoration of fluid balance after exercise requires ingestion of fluid volumes greater than the volume of sweat lost. However, to maintain fluid balance the composition of the ingested solution must allow...

  32. Leucine-enriched essential amino acid supplementation during moderate steady state exercise enhances postexercise muscle protein synthesis

    These results show that leucine added to an optimal EAA supplement can enhance MPS during recovery from endurance exercise. Enhanced MPS after L-EAA supplement may be, in part, because of altered whole-body protein turnover and plasma amino acid availability to muscles. However, muscle...

  33. Protein ingestion before sleep improves postexercise overnight recovery

    Protein ingestion before sleep was effectively absorbed and metabolized and led to significantly greater net protein synthesis compared to a calorie-free control. These data suggest that consumption of protein before bedtime will lead to a greater rate of recovery and a greater amount of protein...

  34. β-alanine supplementation improves YoYo intermittent recovery test performance

    Twelve weeks of supplementation with 3.2 g β-alanine per day improved the performance of amateur soccer players on a soccer match-simulated exercise task.

  35. The effects of soy and whey supplementation on acute hormonal responses to resistance exercise in men

    Read a study that researches the differences between soy and whey protein, and the different hormonal effects between the two proteins.

  36. Acute glycemic and blood lipid response to the ingestion of a candy bar-like protein supplement compared with its candy bar counterpart

    As it was designed, the carb-control protein bar did not spike blood glucose concentrations after consumption. However, both bars led to a robust insulin response which likely was responsible for the extremely low blood glucose concentration observed 45 min after consumption. Blood glucose...

  37. Effect of a pre-workout energy supplement on acute multi-joint resistance exercise

    The participants were able to perform more repetitions in 4 sets with the supplement (26.3 ± 9.2) than with the placebo (23.5 ± 9.4 repetitions; p = 0.022). The supplement improved the performance for 6 of the 8 participants.

  38. 3/4/2011 / Protein-enriched meal replacements do not adversely affect liver, kidney or bone density: an outpatient randomized controlled trial

     Protein-enriched meal replacements (MR) have become increasingly popular among overweight subjects who wish to reduce their body weight. Although MRs are considered a safe and effective method for weight loss and weight management, there is growing concern that the long-term use of a high...

  39. Free acid gel form of β-hydroxy-β-methylbutyrate (HMB) improves HMB clearance from plasma in human subjects compared with the calcium HMB salt

    β-Hydroxy-β--methylbutyrate (HMB) is a natural metabolite of the amino acid leucine. It is thought to be involved in regulating protein metabolism and is used as a supplement to increase the synthesis of muscle protein. HMB can be found as a free acid or as a salt. Most HMB supplements...

  40. 3/4/2011 /Effects of pre-exercise feeding on markers of satellite cell activation

     Satellite cells are normally quiescent, myogenic stem cells located between the basement and plasma membrane. The proliferation and differentiation of satellite cells, as well as their fusion with existing myofibers, are key events leading to the process of muscular hypertrophy. Acute...

  41. Effect of 15 days of betaine ingestion on concentric and eccentric force outputs during isokinetic exercise

    Interpretation of findings/Key practice applications: In this study, betaine supplementation did not affect isokinetic force output or the quality of the workout and, therefore, does not support the ergogenic benefits reported by previous studies. The type of testing in this...

  42. Leucine-protein supplemented recovery feeding enhances subsequent cycling performance in well-trained men

    Dietary protein is in higher demand after intensive exercise for use in energy utilization, muscle repair, and adaptation of body structure to that exercise. The amino acid leucine, specifically, has been identified as a key signaling molecule in protein synthesis.

  43. 3/4/2011 / Acute supplementation with keto analogues and amino acids in rats during resistance exercise

    Ammonia (NH3) and ammonium (NH4+) are produced during exercise as a result of the breakdown of amino acids for energy or the deamination of AMP. Ammonia compounds are toxic and excreted as ammonium in the urine. However, during exercise, production exceeds the rate...

  44. 3/4/2011 / Muscle full effect after oral protein: time-dependent concordance and discordance between human muscle protein synthesis and mTORC1 signaling

    Human muscle protein synthesis (MPS) increases following ingestion or infusion of amino acids (AAs) followed by a plateau at ~120 minutes and return to postabsorptive rates. This return to postabsorptive rates occurs despite continued availability of AAs, in what is called the “muscle...

  45. 3/4/2011 / Short-term recovery from prolonged exercise: exploring the potential for protein ingestion to accentuate the benefits of carbohydrate supplements

    The authors have written a comprehensive review article (19 pages) summarizing the currently available studies examining muscle glycogen resynthesis in response to ingesting varying amounts of carbohydrate during a short-term (ie, > 2 to 6 hours) recovery in humans. The main purpose of the...

  46. 3/4/2011 / Whey protein isolate attenuates strength decline after eccentrically-induced muscle damage in healthy individuals

    Whey protein has been shown to be beneficial following strength training routines for the purpose of gaining muscle, quickening recovery, and reducing soreness. In particular, hydrolyzed whey protein isolate is efficiently absorbed and delivered to damaged muscle cells.In eccentric exercise,...

  47. 3/4/2011 / The effect of L-ornithine hydrochloride ingestion on performance during incremental exhaustive ergometer bicycle exercise and ammonia metabolism during and after exercise

    During exercise, ammonia (NH4+) resulting from protein oxidation can accumulate in the muscle and, among other factors, is a potential cause muscle fatigue. Ammonia and lactic acid disrupt pH homeostasis in the muscle and ammonia can consume inosinic acid that is used to make...

  48. 3/4/2011 / The effect of a low carbohydrate beverage with added protein on cycling endurance performance in trained athletes

    Ingesting carbohydrate (CHO) plus protein (approximately 25% to 30% of total energy content from protein) during prolonged variable-intensity exercise has demonstrated improved aerobic endurance performance beyond that of a CHO supplement alone and may reduce muscle damage. Previous work has...

  49. 3/4/2011 / Excess leucine intake enhances muscle anabolic signaling but not net protein anabolism in young men and women

    Although all essential amino acids (EAAs) stimulate muscle protein synthesis in animal and human models, leucine has unique properties in animal models that have raised interest in leucine as a maintenance therapy for human muscle mass. Specifically, leucine stimulates the cell hypertrophy...

  50. 3/4/2011 / Low-carbohydrate diet does not affect intramyocellular lipid concentration or insulin sensitivity in lean, physically fit men when protein intake is elevated

    There are well established pathologic associations between excess adiposity and insulin resistance. However, insulin resistance has also been shown to be a short-term, rapidly adaptive, physiologic response in lean, physically fit humans. Although the mechanisms for insulin resistance in these...

  51. 3/4/2011 / : Long-term glycine propionyl-l-carnitine supplementation and paradoxical effects on repeated anaerobic sprint performance

    Success in endurance sports is related to an ability to continue with relatively high efforts for extended periods of time. While numerous factors underlie exercise capacity, a primary consideration is that of energy demand vs energy supply. It has been demonstrated that acute glycine...

  52. 3/4/2011 / Acute L-arginine supplementation reduces the O2 cost of moderate-intensity exercise and enhances high-intensity exercise tolerance

    Dietary supplementation with arginine, a substrate for nitric oxide synthesis, might reduce the O2 cost of moderate-intensity exercise and enhance exercise tolerance during severe intensity exercise.

  53. 3/4/2011 / Leucine and ketoisocaproic acid, but not norleucine, stimulate skeletal muscle protein synthesis in neonatal pigs

     Leucine is a branched-chain amino acid that can specifically stimulate protein synthesis. However, it is not clear if leucine itself or one of its downstream metabolites is responsible for stimulating protein synthesis. The authors explored the roles of leucine, its keto-acid...

  54. 3/4/2011 / Protein and carbohydrate supplementation during 5-day aerobic training enhanced plasma volume expansion and thermoregulatory adaptation in young men

     A mixture of carbohydrate and protein supplementation will increase plasma volume and albumin levels during aerobic training, which will reduce heat and cardiovascular strain Subjects: 18 healthy, young males (mean age = 24 y, mean weight = 63 kg, mean BMI = 22 kg/m2); a total of 9...

  55. 3/4/2011 / Effects of ingesting protein in combination with carbohydrate during exercise on endurance performance: a systematic meta-analysis

    This meta-analysis combined the data from 11different studies to evaluate if there are performance benefits associated with the ingestion of a combination of carbohydrate and protein versus protein alone during endurance exercise.

  56. 3/4/2011 / The effects of adding leucine to pre and postexercise carbohydrate beverages on acute muscle recovery from resistance training

     Leucine's ability to augment muscle protein synthesis would lead to a reduction in damage to myofibrillar and cytoskeleton proteins, thereby preventing an increase in serum creatine kinase (CK) and lactate dehydrogenase (LDL) in a subject consuming a leucine-carbohydrate beverage. It was...

  57. 3/4/2011 /Leucine supplementation of a low-protein meal increases skeletal muscle and visceral tissue protein synthesis in neonatal pigs by stimulating mTOR-dependent translation initiation

     Amino acids serve as precursors for protein synthesis and also as cellular signaling molecules to regulate protein synthesis. Leucine (Leu), a branched chain amino acid, consistently stimulates protein synthesis. There is evidence that Leu works through the mTOR signaling pathway via...

  58. 3/4/2011 / Nine weeks of supplementation with a multi-nutrient product augments gains in lean mass, strength, and muscular performance in resistance trained men.

     Creatine monohydrate, carbohydrates, and protein, when consumed before or during one's workout, have consistently shown to increase the gains from resistance training. Many supplements contain these ingredients, often in conjunction with other active ingredients. It is possible that other...

  59. 3/4/2011 /Effect of intermittent blood volume fluctuation of light resistance exercise after ingestion of high-protein snacks on plasma branched-chain amino acid concentrations in young adults

     High-protein snacks ingested 3 hours after a meal elevate the blood concentration of branched-chain amino acids (BCAAs). Muscle uptake and utilization of amino acids may contribute to increases in both mass and strength. However, resistance exercise produces reduced blood flow to various...

  60. 3/4/2011 /Acute supplementation with keto analogues and amino acids in rats during resistance exercise

     Ammonia (NH3) and ammonium (NH4+) are produced during exercise as a result of the breakdown of amino acids for energy or the deamination of AMP. Ammonia compounds are toxic and excreted as ammonium in the urine. However, during exercise, production exceeds the rate of elimination and blood...

  61. 3/4/2011 /The abundance and activation of mTORC1 regulators in skeletal muscle of neonatal pigs are modulated by insulin, amino acids, and age

    The mTOR pathway regulates muscle protein synthesis. There is a high level of protein synthesis, specifically in neonatal pigs so these animals are a convenient model to test the regulation of the mTOR pathway. After meals, there are changes in mRNA translation (i.e., enzyme synthesis) caused by...

  62. 3/4/2011 /PAKs supplement improves immune status and body composition but not muscle strength in resistance trained individuals

     Mixed formula supplements are very popular among recreational and professional weightlifters. Often known as PAKs, these dietary supplements consist of several pills/tablets packaged in the same envelope and are meant to be ingested together. They are intended to provide the consumer with...

  63. 3/4/2011 /Muscle full effect after oral protein: time-dependent concordance and discordance between human muscle protein synthesis and mTORC1 signaling

     Human muscle protein synthesis (MPS) increases following ingestion or infusion of amino acids (AAs) followed by a plateau at ~120 minutes and return to postabsorptive rates. This return to postabsorptive rates occurs despite continued availability of AAs, in what is called the ?muscle full?...

  64. 3/4/2011 /BCAA supplementation lowers perceived exertion but does not affect performance in untrained males

     Branched-chain amino acid (BCAA) supplementation will enhance aerobic performance, ratings of perceived exertion (RPE), or substrate utilization compared with an isocaloric carbohydrate (CHO) beverage or a noncaloric placebo (PLAC) beverage.

  65. 3/4/2011 /Effect of Increased Dietary Protein on Tolerance to Intensified Training

     Athletes often combine high training volume with limited recovery time as a means to improve endurance; however, this approach can result in fatigue and reduced physical and psychological performance. Preliminary data suggest that protein supplementation is beneficial for exercise recovery...

  66. 3/4/2011 /The influence of 8 weeks of whey-protein and leucine supplementation on physical and cognitive performance

    Many military personnel take dietary supplements, presumably to improve their strength and/or endurance, yet there is little to no guidance available for their use. Supplementation with leucine and whey protein has been shown to improve single-bout exercise performance and result in greater...

  67. 3/4/2011 /Effect of High-Protein Feeding on Performance and Nitrogen Balance in Female Cyclists

    Research into the effect of nutritional supplementation to improve exercise performance has been conducted mostly in men. Although it appears that female athletes require ~15%-25% less dietary protein than male athletes, no specific recommendation for protein supplementation of female athletes has...

  68. 3/4/2011 /Long-term glycine propionyl-l-carnitine supplementation and paradoxical effects on repeated anaerobic sprint performance

     Success in endurance sports is related to an ability to continue with relatively high efforts for extended periods of time. While numerous factors underlie exercise capacity, a primary consideration is that of energy demand vs energy supply. It has been demonstrated that acute glycine...

  69. 3/4/2011 /β-Hydroxy-β-methylbutyrate modifies human peripheral blood mononuclear cell proliferation and cytokine production in vitro

     The human immune system is known to overreact to exercise or other common situations, causing stress and inflammation. There are certain foods and compounds that can reduce the level of inflammation. Leucine is a branched chain amino acid that is known to regulate the immune system. However,...

  70. 3/4/2011 /Differential effects of long-term leucine infusion on tissue protein synthesis in neonatal pigs

    Leucine, a branched-chain amino acid, has been shown to stimulate transient skeletal protein synthesis via the mTOR pathway post-ingestion. Its effect has shown to be longer-lasting with the administration of other amino acids in order to prevent a decline of amino acid concentrations in the...

  71. 3/4/2011 /Effect of high-protein feeding on performance and nitrogen balance in female cyclists

     Research into the effect of nutritional supplementation to improve exercise performance has been conducted mostly in men. Although it appears that female athletes require ~15%-25% less dietary protein than male athletes, no specific recommendation for protein supplementation of female...

  72. Differential effects of long-term leucine infusion on tissue protein synthesis in neonatal pigs

    Leucine, a branched-chain amino acid, has been shown to stimulate transient skeletal protein synthesis via the mTOR pathway post-ingestion. Its effect has shown to be longer-lasting with the administration of other amino acids in order to prevent a decline of amino acid concentrations in the...

  73. β-Hydroxy-β-methylbutyrate modifies human peripheral blood mononuclear cell proliferation and cytokine production in vitro

    The human immune system is known to overreact to exercise or other common situations, causing stress and inflammation. There are certain foods and compounds that can reduce the level of inflammation. Leucine is a branched chain amino acid that is known to regulate the immune system. However, many...

  74. Whey and casein labeled with L-[1-13C]leucine and muscle protein synthesis: effect of resistance exercise and protein ingestion

    The combination of repeated training sessions and at least 20 g of post-workout protein has been shown to stimulate muscle protein synthesis (MPS). Protein from cow’s milk is composed mostly of whey and casein; whey is known to be absorbed and utilized more rapidly while casein is known to...

  75. Validation of a single biopsy approach and bolus protein feeding to determine myofibrillar protein synthesis in stable isotope tracer studies in humans

    In order to measure the rate of protein synthesis in response to a nutritional component, subjects are often administered the nutrient that is enriched with a rare isotope. The isotopes are safe and have exactly the same properties, but the fates of the rare isotopes are able to be followed...

  76. Nutritional modulation of training-induced skeletal muscle adaptations

    Skeletal muscle is remarkably malleable and is able to adapt its metabolic and functional potential in response to both external stimuli, such as exercise, and to internal modulators, such as nutrient availability. In this review, the authors examined the effect of nutrient-exercise interactions...

  77. Bolus arginine supplementation affects neither muscle blood flow nor muscle protein synthesis in young men at rest or after resistance exercise

    Essential amino acid concentrations peaked at 30 minutes following ingestion for both ARG and CON drinks.

  78. Higher branched-chain amino acid intake is associated with a lower prevalence of being overweight or obese in middle-aged East Asian and Western adults

    Reduction of excess body weight decreases one of the major risk factors for coronary heart disease. Several studies have reported that a dietary intake with higher protein and lower carbohydrate content promotes loss of body fat without loss of lean body mass. Branched-chain amino acids (BCAA) are...

  79. β-Hydroxy-β-methylbutyrate (HMB) supplementation stimulates skeletal muscle hypertropy in rats via the mTOR pathway (NOTE: Authors abbreviated HMB as HM?)

    β-Hydroxy-β-methylbutyrate (HMB) is a metabolite of leucine, a branched chain amino acid. There is evidence that HMB can reduce muscle breakdown in response to exercise in addition to other muscle wasting situations. HMB likely increases muscle protein synthesis via the mammalian target...

  80. Exercising before protein intake allows for greater use of dietary protein-derived amino acids for de novo muscle protein synthesis in both young and elderly men

    Sarcopenia, or age-related loss of skeletal muscle mass, may result from impaired protein digestion and absorption or a blunted muscle protein synthesis response (ie, anabolic resistance). Little evidence exists in support of either mechanism.

  81. Effect of milk protein addition to a carbohydrate-electrolyte rehydration solution ingested after exercise in the heat

    Insulin is a hormone that stimulates body cells, including muscle, to take up glucose from the blood stream. Patients with type 1 diabetes do not produce insulin and therefore must administer it themselves in conjunction with a meal. During exercise, muscle takes up glucose at a faster rate than...

  82. Branched-chain amino acid supplementation lowers perceived exertion but does not affect performance in untrained males

    Serotonin (5-hydroxytryptophan) is a hormone that may contribute to fatigue during endurance events. BCAAs (including valine, leucine, and isoleucine), due their similar structure, may be able to compete with tryptophan for entry into the brain, which would reduce the amount of serotonin produced...

  83. A comparison of whey to caseinate: A letter to the editor

    Phillips is concerned that the authors used caseinate, an acid form of casein, and not casein itself and therefore should be careful how they report their data and interpret their results.

  84. Reply to letter to the editor

    The authors acknowledge that micellarized casein and acidic caseinate have different physiological properties, and agree that their results cannot be translated to casein. However, they took exception with Phillips? claim that the caseinate and whey showed nearly identical postprandial amino acid...

  85. N-Acetylcysteine in handgrip exercise: plasma thiols and adverse reactions

    N-Acetylcysteine (NAC), a thiol donor with nonspecific antioxidant properties, has been shown in previous studies to delay skeletal muscle fatigue, probably by increasing circulating and myocyte levels of cysteine (CySH) and glutathione (GSH). However, use of NAC to combat fatigue can be limited...

  86. Relieving occupational fatigue by consumption of a beverage containing γ-amino butyric acid

    With modern busy schedules, occupational fatigue is becoming very common. This can negatively affect work performance, as well as other areas of life such as physical performance in recreational sports. γ-Aminobutyric acid (GABA) is a compound endogenously produced from the amino acid...

  87. No effect of short-term amino acid supplementation on variables related to skeletal muscle damage in 100 km ultra-runners – a randomized controlled trial

    Ultra-marathons are races that are at least 100 km and running this extremely long distance causes elevated markers of skeletal damage including creatine kinase, urea, and myoglobin. It has been shown in cyclists that ingestion of protein or amino acids can delay and reduce muscle soreness and...

  88. Effect of increased dietary protein on tolerance to intensified training

    Athletes attempting to improve endurance function often train with periods of high volume and limited recovery. An imbalance between training impulse and recovery often leads to fatigue and disturbances in biologic functioning and psychologic status. Nutrition is frequently used as a tool to help...

  89. High protein diet maintains glucose production during exercise-induced energy deficit: a controlled trial

    Negative energy balance, achieved by a low energy diet and/or an increase in energy expenditure, is often accompanied by a reduction in lean muscle mass. The mechanism of this phenomenon may be explained by the regulation of liver glycogen; under low energy conditions, glycogen stores are low and...

  90. A-Z of nutritional supplements: dietary supplements, sports nutrition foods and ergogenic aids for health and performance - Part 20

    This article provides a brief review on the background and efficacy of four sports nutrition supplements: glycine, histidine-containing dipeptides, inosine, and β-hydroxymethylbutyrate

  91. Mammalian target of rapamycin complex 1 activation is required for the stimulation of human skeletal muscle protein synthesis by essential amino acids

    The use of rapamycin to block signaling through mTORC1demonstrates that mTORC1 activity is required in humans for muscle protein synthetic activity to respond to essential amino acids. These findings support established work in animal skeletal muscle, and provide a foundation to develop...

  92. Postexercise carbohydrate-protein supplementation improves subsequent exercise performance and intracellular signaling for protein synthesis

    Chocolate milk improved times in a time trial after glycogen-depleting exercise compared to an isocaloric carbohydrate beverage and a calorie-free beverage. It is likely that the combination of protein availability and sugar allowed the body to recover faster; the sugar aided in the replenishment...

  93. Influence of tracer selection on protein synthesis rates at rest and postexercise in multiple human

    Resistance exercise has clearly shown to increase the rate of muscle synthesis 24 hrs after exercise; this study shows that endurance exercise also enhances protein synthesis the next day.

  94. Myostatin expression during human muscle hypertrophy and subsequent atrophy: increased myostatin with detraining

    Resistance training decreases myostatin mRNA concentrations, which may lead to the ability to build more muscle mass. On the other hand, stopping a resistance training protocol will cause myostatin mRNA concentrations to increase above pre-training concentrations. However, there are still some...

  95. Whey protein stimulates postprandial muscle protein accretion more effectively than do casein and casein hydrolysate in older men

    Essential amino acids that are crucial for stimulating new muscle protein synthesis appeared more rapidly after consumption of both whey and hydrolyzed casein. However, whey produced greater increases in plasma leucine, and correspondingly the highest increase in protein synthesis. Hydrolyzed...

  96. Effects of immediate postexercise carbohydrate ingestion with and without protein on neutrophil degranulation

    This study replicated this group’s earlier findings that a carbohydrate-protein postexercise feeding can attenuate the decrease in bacterially-stimulated postexercise neutrophil degranulation. However, this study extends this knowledge by showing that protein, at the level fed, offers no...

  97. The actute effects of a low and high dose of oral L-arginine supplementation in young males at rest

    Acute L-arginine supplementation, at either a high or low dose, was not associated with increases in NO metabolites, GH, or IGF-1 in young, healthy subjects. This finding is in general agreement with other studies of L-arginine supplementation in similar subject populations.

  98. A to Z of nutritional supplements: dietary supplements, sports nutrition foods and ergogenic aids for health and performance- Part 21

    AKG is a compound in the tricarboxylic acid (TCA) cycle, and is therefore a key player in energy generation. AKG also provides a source of glutamine to stimulate protein synthesis. Supplementation with AKG may increase anabolic hormones such as insulin, growth factor, and insulin-like growth...

  99. Effects of a dairy supplement and resistance training on lean mass and insulin-like growth factor in women

    The authors hypothesized that overweight women participating in a weight loss/resistance training program would have greater muscle mass and strength gains and lose more body fat when fed yogurt 20 min before and immediately after exercise sessions as compared with an isoenergetic carbohydrate...

  100. Skeletal muscle protein synthesis and the abundance of the mRNA translation initiation repressor PDCD4 are inversely regulated by fasting and refeeding in rats

    Muscle protein synthesis is regulated by a protein complex called mTORC1, or simply mTOR. When activated, mTOR initiates a large number of downstream events including phosphorylation of a protein called S6K1. Recently, S6K1 was observed to phosphorylate another protein called programmed cell death...

  101. Whey protein but not soy protein supplementation alters body weight and composition in free-living overweight and obese adults

    Dietary manipulation is one potential method to control hunger and energy intake. Short-term studies have suggested that dietary protein is more satiating than isoenergetic intake of fat or carbohydrate. Long-term studies of increased protein intake have yielded conflicting outcomes regarding body...

  102. Combined carbohydrate-protein supplementation improves competitive endurance exercise performance in the heat

    Addition of protein to carbohydrate sport beverages can improve performance in long, duration, hot weather endurance events. The mechanism of this benefit is not known, but the additional protein could help regulate body temperature, provide additional energy, and/or help with fluid retention.

  103. Carbohydrate-protein ingestion improves subsequent running capacity towards the end of football-specific intermittent exercise.

    Soccer players often fatigue during a match and performance suffers towards the end of the match. Carbohydrate ingestion during the game is important for glycogen replenishment. Recent studies have shown that the ingestion of protein with carbohydrates may be more effective than ingestion of...

  104. Protein intake does not increase vastus lateralis muscle protein synthesis during cycling

    The continuous usage of the vastus lateralis muscles during endurance exercise does not allow for protein synthesis during exercise. However, protein supplementation is extremely helpful in recovery. Protein does not appear to be detrimental to exercise performance, however, so it may be of some...

  105. Increased consumption of dairy foods and protein during diet- and exercise-induced weight loss promotes fat mass loss and lean mass gain in overweight and obese premenopausal women

    While engaging in a diet and exercise program, consuming a high protein, high dairy (low fat dairy, specifically) was more effective at retaining lean muscle mass while overweight and obese women lost weight. From this experiment, also, it is hypothesized that the higher intakes of calcium led to...

  106. Chronic effect of light resistance exercise after ingestion of a high-protein snack on increase of skeletal muscle mass and strength in young adults

    In this study, continued intake of HPS after a meal together with resistance exercise increased muscle mass and strength. It is estimated that amino acids in blood are highest 30 to 60 minutes following ingestion, which allows for optimal promotion of protein synthesis. Although the NE group...

  107. Effect of combined carbohydrate-protein ingestion on markers of recovery after simulated rugby union match-play

    Physical impacts coupled with the mechanical and metabolic stresses experienced during rugby union match-play cause muscle damage evidenced by increased plasma creatine kinase and myoglobin. Interventions that limit muscle damage may relieve pain, prevent limitations of muscle function, and speed...

  108. Effects of high-dose large neutral amino acid supplementation on exercise, motor skill, and mental performance in Australian Rules Football players

    Fatigue that accumulates over time in a team sport affects the amount and intensity of performance as well as skill execution and decision making. The causes of fatigue are multifactorial and include both central and peripheral factors. Central nervous system-based fatigue may be caused by...

  109. Rapid aminoacidemia enhances myofibrillar protein synthesis and anabolic intramuscular signaling responses after resistance exercise

    Whey protein as a bolus supplement can enhance MPS during recovery from resistance exercise to a greater degree than whey protein as a more frequent, smaller-dose supplement. Because the total consumption and exposure to amino acid supplementation was similar in both conditions, the results show...

  110. 5/3/2012 / Effects of carbohydrates-BCAAs-caffeine ingestion on performance and neuromuscular function during a 2-h treadmill run: a randomized, double-blind, cross-over placebo-controlled study

    A sports beverage with caffeine, carbohydrates, and BCAAs enhanced endurance performance compared to a beverage with very little calories. This is in part due to preservation of neuromuscular function (delaying fatigue) and providing a constant supply of available energy.

  111. Chocolate milk and endurance exercise recovery: Protein balance, glycogen, and performance

    It was impossible to blind the participants as to which beverage they were consuming, which may have played a psychological role in the time to exhaustion test.

  112. A to Z of nutritional supplements: dietary supplements, sports nutrition foods and ergogenic aids for health and performance- Part 32

    Protein, in doses of about 20 g, is recommended immediately after a workout and through the rest of the 24 hour post-workout period in order to maximize the rate of muscle protein synthesis. Animal sources of protein (meat, eggs, and especially whey) and soy protein are high quality protein...

  113. Effects of isocaloric carbohydrate vs. carbohydrate-protein supplements on cycling time to exhaustion

    During a 3 hour recovery time in between exercise sessions, the addition of protein to a carbohydrate beverage did not appear to aid in restoring glycogen, calorie content being the same.

  114. A moderate acute increase in physical activity enhances nutritive flow and the muscle protein anabolic response to mixed nutrient intake in older adults

    The anabolic nature of amino acids was indeed observed when exercise was performed the evening before consumption of the amino acid beverage. An increase in blood flow and amino acid delivery to muscle cells was key in the mechanism by which exercise enhanced these anabolic effects. Routine...

  115. Effect of combined β-alanine and sodium bicarbonate supplementation on cycling performance

    Supplementation with β-alanine led to a 37% likelihood of increased performance and a 0% likelihood of decreased performance when taken by these highly trained cyclists for 28 days.  NaHCO3 improved their performance to a greater degree.  There was only a small additive effect of...

  116. Effects of a carbohydrate-, protein-, and ribose-containing repletion drink during 8 weeks of endurance training on aerobic capacity, endurance performance, and body composition

    Regularly consuming a post-workout beverage that contained carbohydrates, protein, ribose, vitamins, and minerals did not improve body composition or aerobic capacity any more than a beverage that had only carbohydrates. With that said, the data suggested that the beverage with protein, ribose,...

  117. A-Z of nutritional supplements: dietary supplements, sports nutrition foods and ergogenic aids for health and performance- Part 35

    There have not been many studies investigating the effects of supplementation with selenium or serine on sports performance, but there is not evidence to date that supports use of either of these supplements. Sibutramine, though an effective weight loss drug, offers more risk than benefit in...

  118. Improved training tolerance by supplementation with alpha-keto acids in untrained young adults: a randomized, double-blind, placebo-controlled trial

    Supplementation with branched chain keto acids or α-ketoglutarate improved tolerance to training and enabled untrained participants to perform and maintain high levels of intense exercise for 4 weeks. Therefore, strength and endurance was augmented in many regards. This may especially be...

  119. Dietary protein to maximize resistance training: a review and examination of protein spread and change theories

    These data support both the protein spread theory and the protein change theory.  For individuals, these data suggest that an approximate 20% increase in dietary protein- an approximate increase of about 1.31 g protein/kg body weight/day to equal a total of about 2.09 g/kg/day total is an...

  120. Carbohydrate-protein coingestion improves multiple-sprint running performance

    The carbohydrate-protein beverage improved cruising and sprinting speed compared to carbohydrate-only beverage.

  121. Nutrient timing revisited: is there a post-exercise anabolic window?: Post-exercise nutrient timing

    One overall limitation of this review is that it focused primarily on the bodybuilder and strength athlete. There was little discussion of other types of athletes, for whom post-exercise recovery can be equally important. It would have been helpful if the article had been written from the...

  122. A-Z of nutritional supplements: dietary supplements, sports nutrition foods and ergogenic aids for health and performance: Part 42

    Learn about Vanadium, Valine, and Oxygenated water, and how they affect sports performance, whether they improve strength, and more.

  123. Contemporary Sports Nutrition Abstracts and Articles

    On this page, you will find helpful sports nutrition articles and abstracts culled from 47 nutrition and exercise journals from July 2015.
    The articles below were selected only if they included research in humans, although exceptions were made for particularly interesting and...

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