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Stone M, Clayton ZS, Buono MJ, Kern M. Exercise intensity influences plasma and sweat amino acid concentrations: a crossover trial. J Sports Med Phys Fitness 2021; 62:525-530. [PMID: 33687176 DOI: 10.23736/s0022-4707.21.12134-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND The purpose of this study was to explore the relationship between concentrations of amino acid (AA) and related metabolites in plasma and sweat obtained before and after exercise performed at different intensities and therefore different rates of sweat loss. METHODS Ten subjects completed a maximally ramped exercise test and three 30-min submaximal (45/60/75% VO2max) exercise bouts. Blood samples were collected before/after the exercise bouts and sweat was collected from the forearm throughout. Samples were analyzed for concentrations of AA and related molecules. RESULTS Sweat AA excretion rate was higher during the 60% bout compared to the 45% bout but was similar in comparison to the 75% indicating a plateau in rates of sweat AA losses as sweat rate increased. Plasma concentrations of AAs, urea, ammonia, and other non-proteinogenic AAs were not significantly different between exercise bouts performed at 45 and 60%. Exercise at 75% tended to reduce concentrations of sweat amino acids with significantly depressed concentrations of glycine, lysine, serine, threonine, histidine, arginine, tryptophan, aspartate and ornithine. CONCLUSIONS Overall, this research suggests that increasing exercise intensity increases AA metabolism as demonstrated by reduced plasma AA concentrations and increased excretion through sweat glands, which is mediated by a mechanism yet to be identified.
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Affiliation(s)
- Michael Stone
- Department of Exercise and Nutritional Science, San Diego State University, San Diego, CA, USA
| | - Zachary S Clayton
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | - Michael J Buono
- Department of Exercise and Nutritional Science, San Diego State University, San Diego, CA, USA
| | - Mark Kern
- Department of Exercise and Nutritional Science, San Diego State University, San Diego, CA, USA -
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Baur DA, Saunders MJ. Carbohydrate supplementation: a critical review of recent innovations. Eur J Appl Physiol 2020; 121:23-66. [PMID: 33106933 DOI: 10.1007/s00421-020-04534-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 10/12/2020] [Indexed: 12/29/2022]
Abstract
PURPOSE To critically examine the research on novel supplements and strategies designed to enhance carbohydrate delivery and/or availability. METHODS Narrative review. RESULTS Available data would suggest that there are varying levels of effectiveness based on the supplement/supplementation strategy in question and mechanism of action. Novel carbohydrate supplements including multiple transportable carbohydrate (MTC), modified carbohydrate (MC), and hydrogels (HGEL) have been generally effective at modifying gastric emptying and/or intestinal absorption. Moreover, these effects often correlate with altered fuel utilization patterns and/or glycogen storage. Nevertheless, performance effects differ widely based on supplement and study design. MTC consistently enhances performance, but the magnitude of the effect is yet to be fully elucidated. MC and HGEL seem unlikely to be beneficial when compared to supplementation strategies that align with current sport nutrition recommendations. Combining carbohydrate with other ergogenic substances may, in some cases, result in additive or synergistic effects on metabolism and/or performance; however, data are often lacking and results vary based on the quantity, timing, and inter-individual responses to different treatments. Altering dietary carbohydrate intake likely influences absorption, oxidation, and and/or storage of acutely ingested carbohydrate, but how this affects the ergogenicity of carbohydrate is still mostly unknown. CONCLUSIONS In conclusion, novel carbohydrate supplements and strategies alter carbohydrate delivery through various mechanisms. However, more research is needed to determine if/when interventions are ergogenic based on different contexts, populations, and applications.
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Affiliation(s)
- Daniel A Baur
- Department of Physical Education, Virginia Military Institute, 208 Cormack Hall, Lexington, VA, 24450, USA.
| | - Michael J Saunders
- Department of Kinesiology, James Madison University, Harrisonburg, VA, 22801, USA
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Gervasi M, Sisti D, Amatori S, Donati Zeppa S, Annibalini G, Piccoli G, Vallorani L, Benelli P, Rocchi MBL, Barbieri E, Calavalle AR, Agostini D, Fimognari C, Stocchi V, Sestili P. Effects of a commercially available branched-chain amino acid-alanine-carbohydrate-based sports supplement on perceived exertion and performance in high intensity endurance cycling tests. J Int Soc Sports Nutr 2020; 17:6. [PMID: 31959202 PMCID: PMC6971972 DOI: 10.1186/s12970-020-0337-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 01/13/2020] [Indexed: 02/07/2023] Open
Abstract
Background Sports nutritional supplements containing branched-chain amino acids (BCAA) have been widely reported to improve psychological and biological aspects connected to central fatigue and performance in endurance exercise, although the topic is still open to debate. The aim of the present study was to determine whether the intake of a commercially available BCAA-based supplement, taken according to the manufacturer’s recommendations, could affect the rating of perceived exertion (RPE) and performance indexes at the beginning (1d) and end of a 9-week (9w) scheduled high intensity interval training program, with an experimental approach integrating the determination of psychometric, performance, metabolic and blood biochemical parameters. Methods This was a randomized double-blind placebo-controlled study. Thirty-two untrained, healthy young adults (20 males and 12 female) were enrolled. A high-intensity endurance cycling (HIEC) test was used to induce fatigue in the participants: HIEC consisted in ten 90 s sprints interspersed by ten 3 min recovery phases and followed by a final step time to exhaustion was used. In parallel with RPE, haematological values (creatine kinase, alanine, BCAA, tryptophan, ammonia and glucose levels), and performance indexes (maximal oxygen consumption - VO2max, power associated with lactate thresholds - WLT1, WLT2 and time to exhaustion - TTE) were assessed. All subject took the supplement (13.2 g of carbohydrates; 3.2 g of BCAA and 1.6 g of L-alanine per dose) or placebo before each test and training session. Dietary habits and training load were monitored during the entire training period. Results The administration of the supplement (SU) at 1d reduced RPE by 9% during the recovery phase, as compared to the placebo (PL); at 9w the RPE scores were reduced by 13 and 21% during the sprint and recovery phase, respectively; at 9w, prolonged supplement intake also improved TTE and TRIMP. SU intake invariably promoted a rapid increase (within 1 h) of BCAA serum blood levels and prevented the post-HIEC tryptophan: BCAA ratio increase found in the PL group, at both 1d and 9w. There was no difference in dietary habits between groups and those habits did not change over time; no difference in glycemia was found between SU and PL. VO2max, WLT1 and WLT2 values improved over time, but were unaffected by supplement intake. Conclusions On the whole, these results suggest that i) the intake of the BCAA-based commercially available supplement used in this study reduces RPE as a likely consequence of an improvement in the serum tryptophan: BCAA ratio; ii) over time, reduced RPE allows subjects to sustain higher workloads, leading to increased TRIMP and TTE.
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Affiliation(s)
- Marco Gervasi
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Davide Sisti
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Stefano Amatori
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Sabrina Donati Zeppa
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Giosuè Annibalini
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Giovanni Piccoli
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Luciana Vallorani
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Piero Benelli
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Marco B L Rocchi
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Elena Barbieri
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy.,Interuniversity Institute of Myology, Perugia, Italy
| | - Anna R Calavalle
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Deborah Agostini
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Carmela Fimognari
- Department for Life Quality Studies, Alma Mater Studiorum, University of Bologna, Rimini, Italy
| | - Vilberto Stocchi
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Piero Sestili
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy.
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McCormack WP, Hoffman JR, Pruna GJ, Jajtner AR, Townsend JR, Stout JR, Fragala MS, Fukuda DH. Effects ofl-Alanyl-l-Glutamine Ingestion on One-Hour Run Performance. J Am Coll Nutr 2015; 34:488-96. [DOI: 10.1080/07315724.2015.1009193] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Nogusa Y, Mizugaki A, Hirabayashi-Osada Y, Furuta C, Ohyama K, Suzuki K, Kobayashi H. Combined supplementation of carbohydrate, alanine, and proline is effective in maintaining blood glucose and increasing endurance performance during long-term exercise in mice. J Nutr Sci Vitaminol (Tokyo) 2015; 60:188-93. [PMID: 25078375 DOI: 10.3177/jnsv.60.188] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Carbohydrate supplementation is extremely important during prolonged exercise because it maintains blood glucose levels during later stages of exercise. In this study, we examined whether maintaining blood glucose levels by carbohydrate supplementation could be enhanced during long-term exercise by combining this supplementation with alanine and proline, which are gluconeogenic amino acids, and whether such a combination would affect exercise endurance performance. Male C57BL/6J mice were orally administered either maltodextrin (1.25 g/kg) or maltodextrin (1.0 g/kg) with alanine (0.225 g/kg) and proline (0.025 g/kg) 15 min before running for 170 min. Combined supplementation of maltodextrin, alanine, and proline induced higher blood glucose levels than isocaloric maltodextrin alone during the late exercise phase (100-170 min). The hepatic glycogen content of mice administered maltodextrin, alanine, and proline was higher than that of mice ingesting maltodextrin alone 60 min after beginning exercise, but the glycogen content of the gastrocnemius muscle showed no difference. We conducted a treadmill running test to determine the effect of alanine and proline on endurance performance. The test showed that running time to exhaustion of mice that were supplemented with maltodextrin (2.0 g/kg) was longer than that of mice that were supplemented with water alone. Maltodextrin supplementation (1.0 g/kg) with alanine (0.9 g/kg) and proline (0.1 g/kg) further increased running time to exhaustion compared to maltodextrin alone (2.0 g/kg). These results indicate that combined supplementation of carbohydrate, alanine, and proline is effective for maintaining blood glucose and hepatic glycogen levels and increasing endurance performance during long-term exercise in mice.
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Affiliation(s)
- Yoshihito Nogusa
- Frontier Research Labs, Institute for Innovation, Ajinomoto Co., Inc
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