Ralf Jäger

Position statement: The International Society of Sports Nutrition (ISSN) provides an objective and critical review of the mechanisms and use of probiotic supplementation to optimize the health, performance, and recovery of athletes. Based on the current available literature, the conclusions of the ISSN are as follows: Probiotics are live microorgan...

Position statement The International Society of Sports Nutrition (ISSN) provides an objective and critical review related to the intake of protein for healthy, exercising individuals. Based on the current available literature, the position of the Society is as follows: 1) An acute exercise stimulus, particularly resistance exercise, and protein i...

Position Statement: The International Society of Sports Nutrition (ISSN) presents this position based on a critical examination of the literature surrounding the effects of long-chain omega-3 polyunsaturated fatty acid (ω-3 PUFA) supplementation on exercise performance, recovery, and brain health. This position stand is intended to provide a scient...

This study examined the effects of acute paraxanthine (PXN) ingestion on markers of cognition, executive function, and psychomotor vigilance. In a randomized, double blind, placebo-controlled, crossover, and counterbalanced manner, 13 healthy male and female participants were randomly assigned to consume a placebo (PLA) or 200 mg of PXN (ENFINITY™,...

Leucine is regarded as an anabolic trigger for the mTORC1 pathway and the stimulation muscle protein synthesis rates. More recently, there has been an interest in underpinning the relevance of BCAA-containing dipeptides and their intact absorption into circulation to regulate muscle anabolic responses. We investigated the effects of dileucine and l...

Introduction The biotransformation of minerals through glycosylation by microorganisms, such as yeast or probiotics, can produce nutrients bound to a food matrix, potentially enhancing their bioavailability. This study aimed to compare the absorption kinetics of iron bound to a glycoprotein matrix (GPM) with those of ferrous bisglycinate chelate (F...

Supplementation of probiotic strains can enhance the absorption of amino acids from protein in the gut. The purpose of this study was to assess if supplementation of a multi-strain probiotic or a postbiotic, consisting of the same strains, would alter the absorption of individual and total amino acids following ingestion of a plant-based meal. Sixt...

1-Methylxanthine (1-MX) is the major metabolite of caffeine and paraxanthine and might contribute to their activity. 1-MX is an adenosine receptor antagonist and increases the release and survivability of neurotransmitters; however, no study has addressed the potential physiological effects of 1-MX ingestion. The aim of this study was to compare th...

Background The complex relationship among sleep, exercise, and the gut microbiome presents a unique opportunity to improve health and wellness. Here, we conducted the first large-scale investigation into the influence of a novel elite athlete-derived probiotic, consisting of a multi-strain Lactobacillus consortium, on sleep quality, exercise recove...

Background The essential amino acid leucine (LEU) plays a crucial role in promoting resistance-training adaptations. Dileucine (DILEU), a LEU-LEU dipeptide, increases MPS rates, however its impact on resistance training outcomes remains unexplored. This study assessed the effects of DILEU supplementation on resistance training adaptations. Methods...

Position Statement: The International Society of Sports Nutrition (ISSN) bases the following position stand on an analysis of the literature regarding the effects of β-Hydroxy-β-Methylbutyrate (HMB). The following 12 points have been approved by the Research Committee of the Society: 1. HMB is a metabolite of the amino acid leucine that is naturall...

Paraxanthine (PXN) is the main metabolite of caffeine (CAF). PXN supplementation has been shown to increase measures of cognition, memory, reasoning, response time, and sustained attention; however, no preclinical study has compared the effects of PXN with those of CAF. The aim of this study was to compare the effects of PXN and CAF on memory and r...

Purpose L-Ascorbic acid (vitamin C) is an essential water-soluble vitamin that plays an important role in various physiological functions, including immune health. The stability of vitamin C in the gastrointestinal tract its bioavailability is limited. This study aimed to investigate if a liposomal form of vitamin C can increase absorption compared...

Background: This study aimed to conduct a detailed and comparative analysis of body composition and dietary habits in elite swimming and water polo athletes. Through the examination of these key parameters, this study seeks to compare the dietary intake of these two distinct aquatic sports disciplines. Methods: A total of 10 top-level swimmers and...

Background: Ashwagandha has been reported to reduce stress and attenuate cognitive decline associated with inflammation and neurodegeneration in clinical populations. However, the effects as a potential nootropic nutrient in younger populations are unclear. This study examined the effects of liposomal ashwagandha supplementation on cognitive functi...

White kidney bean (Phaseolus vulgaris L.) extracts can aid weight management by reducing calorie intake from complex carbohydrates through alpha-amylase inhibition. We examined the impact of a proprietary aqueous extract from whole dried white kidney beans standardized by its alpha-amylase inhibitor activity (Phase 2 white kidney bean extract (WKBE...

This study investigated if paraxanthine (PX) impacts energy expenditure, lipolysis and perceptual responses. In a randomized, double-blind, placebo-controlled, crossover fashion, 21 adults (13 M, 8 F; 26.0 ± 6.4 years, 174.9 ± 11.5 cm, 81.0 ± 15.7 kg body mass, 26.3 ± 3.4 kg/m2) consumed a placebo (PLA), 100 mg (PX100), 200 mg (PX200), and 300 mg o...

Rationale Intense exercise promotes fatigue and can impair cognitive function, particularly toward the end of competition when decision-making is often critical for success. For this reason, athletes often ingest caffeinated energy drinks prior to or during exercise to help them maintain focus, reaction time, and cognitive function during competiti...

Biotransformation of minerals via glycosylation by microorganisms such as yeast and/or probiotics yields nutrients bound to a food matrix, resulting in increased bioavailability. The purpose of this study was to compare the effects of glycoprotein matrix-bound zinc (GPM) on absorption compared to inorganic zinc oxide. Sixteen participants ingested...

Background: Microalgae like Phaeodactylum tricornutum (PT) contain the carotenoid, fucoxanthin, which has been purported to promote fat loss, lower blood lipids, and improve glucose management. This study examined whether dietary supplementation with microalgae extracts from PT containing 4.4 mg/d of fucoxanthin affects changes in body composition...

In recent years, postbiotics have increased in popularity, but the potential relevancy of postbiotics for augmenting exercise performance, recovery, and health is underexplored. A systematic literature search of Google Scholar and PubMed databases was performed with the main objective being to identify and summarize the current body of scientific l...

Feeding and resistance exercise stimulate myofibrillar protein synthesis rates (MPS) in healthy adults. This anabolic characterization of 'healthy adults' has been namely focused on males. Therefore, the purpose of this study was to examine the temporal responses of MPS and anabolic signaling to resistance exercise alone or combined with the ingest...

The objective of the study was to examine the impact of a multi-strain probiotic (MSP) on sleep, physical activity, and body composition changes. We used a randomised, double-blind, placebo-controlled approach with 70 healthy men and women (31.0 ± 9.5 years, 173.0 ± 10.4 cm, 73.9 ± 13.8 kg, 24.6 ± 3.5 kg/m ² ) supplemented daily with MSP (4 × 10 ⁹...

Seven healthy, physically active men (n = 3) and women (n = 4) (30.7 ± 7.5 years, 172.7 ± 8.7 cm, 70.4 ± 11.6 kg, 23.6 ± 4.1 kg/m², 49.2 ± 8.4 mL/kg/min) supplemented for 14 days with a placebo (PLA) or 1 × 10¹⁰ CFU doses of the probiotic Veillonella atypica FB0054 (FitBiomics, New York, NY). Participants had safety panels, hemodynamics, lactate, a...

Position Statement: The International Society of Sports Nutrition (ISSN) presents this position based on a critical examination of literature surrounding the effects of essential amino acid (EAA) supplementation on skeletal muscle maintenance and performance. This position stand is intended to provide a scientific foundation to athletes, dietitians...

Objective To examine the efficacy of supplementing with a multi-strain probiotic (MSP) on changes associated with mood, anxiety, and neurotransmitter levels. Method In a randomized, double-blind, placebo-controlled fashion, 70 healthy men and women (31.0 ± 9.5 years, 173.0 ± 10.4 cm, 73.9 ± 13.8 kg, 24.6 ± 3.5 kg/m²) supplemented with a single cap...

Introduction: the aspect of cognitive performance is also attracting growing interest in sport; particularly in activities that require a commitment from the point of view of concentration, it would be important to optimize this aspect. Methods: Here we present the evaluation of two possible supplements to improve cognitive performance: beetroot (B...

Balenine possesses some of carnosine’s and anserine’s functions, yet it appears more resistant to the hydrolysing CN1 enzyme. The aim of this study was to elucidate the stability of balenine in the systemic circulation and its bioavailability in humans following acute supplementation. Two experiments were conducted in which (in vitro) carnosine, an...

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 energy drink (ED) or energy shot (ES) consumption on acute exercise performance, metabolism, and cognition, along with synergistic exercise-related performance outcomes and tra...

Carnosine (β-alanyl-L-histidine) and its methylated analogues anserine and balenine are highly concentrated endogenous dipeptides in mammalian skeletal muscle that are implicated in exercise performance. Balenine has a much better bioavailability and stability in human circulation upon acute ingestion, compared to carnosine and anserine. Therefore,...

Weizmannia coagulans GBI-30, 6086 (BC30) has previously been shown to increase protein digestion in an in vitro model of the stomach and small intestine and amino acid appearance in healthy men and women after ingestion of milk protein concentrate. The impact of ingesting BC30 with other protein sources or in other demographics is largely unknown....

The activation of the mechanistic target of rapamycin complex 1 (mTORC1), a master regulator of protein synthesis, by anabolic stimuli (such as muscle contraction or essential amino acids) involves its translocation to the cell periphery. Leucine is generally considered the most anabolic of amino acids for its ability to independently modulate musc...

Background: Ashwagandha (Withania somnifera) has been reported to decrease perceptions of stress, enhance mood, and improve cognitive function. However, it is currently unknown whether acute ashwagandha supplementation affects memory and cognitive function. This study evaluated the effects of acute ashwagandha extract ingestion on executive functi...

Intense physical activity is often associated with undesirable physiological changes, including increased inflammation, transient immunodepression, increased susceptibility to infections, altered intestinal barrier integrity, and increased oxidative stress. Several trials suggested that probiotics supplementation may have beneficial effects on spor...

Objectives: The purpose of this study was to compare the effects of two acute doses of Capsiate (CAP; 6 vs. 12 mg) on upper body resistance exercise performance in trained men. Methods: Using a randomized, crossover and double-blind design, 20 resistance-trained males were supplemented with low-dose CAP (6 mg), high-dose CAP (12 mg) or placebo 4...

Background: This study’s aim was to evaluate the efficacy and safety of 14-days oral supplementation of a standardized hops extract containing 30% alpha acids, Humulus lupulus L. on individuals with osteoarthritis of the knee. Methods: Thirty-three subjects (26 female, 7 male, 57.0 ± 6.9 years) participated in this randomized, double-blind, multi-...

In 2011, we published a paper providing an overview about the bioavailability, efficacy, and regulatory status of creatine monohydrate (CrM), as well as other “novel forms” of creatine that were being marketed at the time. This paper concluded that no other purported form of creatine had been shown to be a more effective source of creatine than CrM...

Paraxanthine is a natural dietary ingredient and the main metabolite of caffeine in humans. Compared to caffeine, paraxanthine exhibits lower toxicity, lesser anxiogenic properties, stronger locomotor activating effects, greater wake promoting properties, and stronger dopaminergic effects. The purpose of this study was to evaluate the potential ben...

Paraxanthine (PXN) is a metabolite of caffeine that has recently been reported to enhance cognition at a dose of 200 mg. Objective: To determine the acute and short-term (7-day) effects of varying doses of PXN on cognitive function and side effects. Methods: In a double blind, placebo-controlled, crossover, and counterbalanced manner, 12 health...

Background Acute capsaicinoid and capsinoid supplementation has endurance and resistance exercise benefits; however, if these short-term performance benefits translate into chronic benefits when combined with resistance training is currently unknown. This study investigated changes of chronic Capsiate supplementation on muscular adaptations, inflam...

Background: Chronic oral ATP supplementation benefits cardiovascular health, muscular performance, body composition, and recovery while attenuating muscle breakdown and fatigue. A single 400 mg dose of oral ATP supplementation improved lower body resistance training performance and energy expenditure in recreational resistance trained males, howeve...

Paraxanthine or 1,7-dimethylxanthine is a natural dietary component and the main metabolite of caffeine in humans. A battery of toxicological studies was conducted in accordance with international guidelines to investigate mutagenicity, genotoxicity and acute and repeated-dose oral toxicity in rats of synthetic paraxanthine (ENFINITY™, Ingenious In...

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 functio...

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...

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 ac...

❶ 8-weeks of non-linear resistance training in combination with high doses (48g) of rice protein • decreases fat-mass • increases lean body mass • increases skeletal muscle hypertrophy • increases power • increases strength comparable to 48g of whey protein. J.M. Joy, R.P. Lowery, R. Jäger, M. Purpura, E.O. De Souza, J.E. Dudeck, J.M. Wilson: Rice...

The fate of dietary protein in the gut is determined by microbial and host digestion and utilization. Fermentation of proteins generates bioactive molecules that have wide-ranging health effects on the host. The type of protein can affect amino acid absorption, with animal proteins generally being more efficiently absorbed compared with plant prote...

Background 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...

Background Probiotic Bacillus coagulans GBI-30, 6086 (BC30) has been shown to increase protein digestion in an in vitro model of the stomach and small intestine. Once active in the small intestine after germination, BC30 aids the digestion of carbohydrates and proteins. The extent to which BC30 administration may impact protein digestion and amino...

Background Chronic supplementation with ashwagandha (Withania somnifera root) reduces feelings of stress, improves mood and cognitive function. The potential benefits of acute ashwagandha supplementation on sustained attention, cognitive flexibility, and/or working memory are currently unknown. The purpose of this double-blind, placebo-controlled,...

Purpose of review: This is a review of the most up-to-date research on the effectiveness of probiotic supplementation for outcomes related to athletes and physical activity. The focus is on clinical research incorporating exercise and/or physically active participants on the nutritional effectiveness of single and multistrain preparations. Recent...

Adenosine-5′-triphosphate (ATP) is the primary source of energy for cells and oral supplementation with ATP offers numerous different health benefits, including the regulation of blood flow and muscle contraction. In this study, ATP, disodium salt, was administered by gavage to rats for 90 consecutive days at doses of 0 (control), 500, 1000, and 20...

The microorganisms in the gastrointestinal tract play a significant role in nutrient uptake, vitamin synthesis, energy harvest, inflammatory modulation, and host immune response, collectively contributing to human health. Important factors such as age, birth method, antibiotic use, and diet have been established as formative factors that shape the...

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...

BACKGROUND Protein supplementation is a well‐established nutritional strategy in weight management, and frequently used to improve post‐exercise recovery and enhance training adaptations. The type of protein can affect amino acid absorption, with animal proteins generally being more efficiently absorbed compared to plant proteins. In contrast to an...

Context: Capsaicinoids and capsinoids (CAP) are natural substances found primarily in chili peppers and other spicy foods that agonize the transient receptor potential vanilloid-1 in the mouth, stomach, and small intestine. Several studies have shown CAP to be a potential antiobesity agent and to exhibit an analgesic effect in both rodents and hum...

Background: It is known that unaccustomed exercise-especially when it has an eccentric component-causes muscle damage and subsequent performance decrements. Attenuating muscle damage may improve performance and recovery, allowing for improved training quality and adaptations. Therefore, the current study sought to examine the effect of two doses o...

Probiotics offer numerous health benefits, including digestive and immune health. Improved digestive health is linked to a more efficient absorption of important nutrients from our diet. This review focused on the rationale of using the probiotic Bacillus coagulans GBI-30, 6086 to aid protein absorption and utilization. B. coagulans GBI-30, 6086 ca...

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 nutritio...

Background: Capsaicinoids (CAPs) found in chili peppers and pepper extracts, are responsible for enhanced metabolism. The objective of the study was to evaluate the effects of CAPs on body fat and fat mass while considering interactions with body habitus, diet and metabolic propensity. Methods: Seventy-five (N = 75) volunteer (male and female, age:...

It is known that unaccustomed exercise especially that with an eccentric component causes muscle damage and subsequent performance decrements. Attenuating muscle damage may improve performance and allow for greater performance adaptations. Curcumin, a highly pleiotropic molecule, interacts with multiple inflammatory pathways, primarily by inhibitin...

The training of novice and competitive athletes involves the incorporation of unaccustomed exercise, likely to result in skeletal muscle tissue damage. The initial response, known to result in muscle soreness and swelling, and decreased forced production, is followed by a secondary inflammatory response integral in the skeletal muscle repair and re...

Introduction Krill oil supplementation has been shown to improve postexercise immune function; however, its effect on muscle hypertrophy is currently unknown. Therefore, the aim of present study was to investigate the ability of krill oil to stimulate mTOR signaling and its ability to augment resistance training-induced changes in body composition...

The training of novice and competitive athletes involves the incorporation of unaccustomed exercise, likely to result in skeletal muscle tissue damage. The initial response, known to result in muscle soreness and swelling, and decreased forced production, is followed by a secondary inflammatory response integral in the skeletal muscle repair and re...

We examined if 12 weeks of capsaicinoid (CAP) supplementation affected appetite, body composition and metabolic health markers. Seventy seven healthy male and female volunteers (30 ± 1 y, 171.2 ± 9.8 cm, 81.0 ± 2.2 kg, 27.5 ± 0.6 kg/m2) were randomly assigned to ingest either low-dose CAP (2 mg/d; L-CAP, n = 27), high-dose CAP (4 mg/d; H-CAP, n = 2...

Objective: Oral adenosine-5'-triphosphate (ATP) administration has failed to increase plasma ATP levels; however, chronic supplementation with ATP has shown to increase power, strength, lean body mass, and blood flow in trained athletes. The purpose of this study was to investigate the effects of ATP supplementation on postexercise ATP levels and...

Probiotics have immunomodulatory effects. However, little is known about the potential benefit of probiotics on the inflammation subsequent to strenuous exercise. In a double-blind, randomized, placebo controlled, crossover design separated by a 21-day washout, 15 healthy resistance-trained men ingested an encapsulated probiotic Streptococcus (S.)...

Effects of MusclePharm Assault BlackTM on lower extremity spinal excitability and postactivation potentiation: A pilot study Brian Wallace*, Haley Bergstrom, Kelly Wallace Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, KY 40506, USA Email: brian.wallace@uky.edu; brian.wallace@northern.edu Background: Caffeine h...

Objective: Probiotics have been reported to support healthy digestive and immune function, aid in protein absorption, and decrease inflammation. Further, a trend to increase vertical jump power has been observed following co-administration of protein and probiotics in resistance-trained subjects. However, to date the potential beneficial effect of...

Adenosine-5'-triphosphate (ATP) supplementation helps maintain performance under high fatiguing contractions and with greater fatigue recovery demands also increase. Current evidence suggests that the free acid form of β-hydroxy-β-methylbutyrate (HMB-FA) acts by speeding regenerative capacity of skeletal muscle following high intensity or prolonged...

It is known that endothelial dysfunction (ED) may increase the risk of cardiovascular disease (CVD). ED can be measured as a decreased flow-mediated dilation (FMD) response, using occlusion and subsequent dilation response of the brachial artery. Increased levels of inflammatory molecules contribute to ED, and increase CVD. Curcumin, a highly pleio...

It is known that endothelial dysfunction (ED) may increase the risk of cardiovascular disease (CVD). ED can be measured as a decreased flow‐mediated dilation (FMD) response, using occlusion and subsequent dilation response of the brachial artery. Increased levels of inflammatory molecules contribute to ED, and increase CVD. Curcumin, a highly pleio...

Objective: Probiotics have been purported to reduce inflammation. However, little is known about the potential benefit of probiotics in reducing inflammation and subsequent performance decrements associated with strenuous exercise in healthy athletes. Such evidence may allow greater training adaptation and subsequent increases in performance. There...

Curcumin, a turmeric extract, may protect against cardiovascular diseases by enhancing endothelial function. In this randomized controlled double-blind parallel prospective study, fifty-nine healthy adults were assigned to placebo, 50 mg (50 mg), or 200 mg (200 mg) curcumin, for 8 weeks. The higher curcumin (200 mg) supplementation produced a dose-...

Position statement The International Society of Sports Nutrition (ISSN) provides an objective and critical review of the mechanisms and use of beta-alanine supplementation. Based on the current available literature, the conclusions of the ISSN are as follows: 1) Four weeks of beta-alanine supplementation (4–6 g daily) significantly augments muscle...

Probiotics have been shown to reduce the number, duration and severity of upper respiratory tract infections (URTI) and gastrointestinal (GI) distress in the general population and in at risk sub-groups such as the elderly, children attending care centers, or athletes. Strategies to prevent URTI in athletes include avoiding overtraining, providing...