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1.
Nutrients ; 15(4)2023 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-36839281

RESUMO

This study investigated 10 weeks of ß-alanine (BA) supplementation on changes in cognitive function, mood, and physical performance in 100 older adults (70.6 ± 8.7 y). Participants were randomized into a BA (2.4 g·d-1) or placebo (PL) group. Testing occurred prior to supplementation (PRE), at the midpoint (MID), and at week-10 (POST). Participants completed cognitive function assessments, including the Montreal cognitive assessment (MOCA) and the Stroop pattern recognition test, at each testing session. Behavioral questionnaires [i.e., the profile of mood states, geriatric depression scale (GDS), and geriatric anxiety scale (GAS)] and physical function assessments (grip strength and timed sit-to-stand) were also conducted. No difference between groups was noted in MoCA scores (p = 0.19). However, when examining participants whose MOCA scores at PRE were at or below normal (i.e., ≤26), participants in BA experienced significant improvements in MOCA scores at MID (13.6%, p = 0.009) and POST (11.8%, p = 0.016), compared to PL. No differences were noted in mood scores, GAS, or any of the physical performance measures. A significant decrease was observed in the GDS for participants consuming BA but not in PL. Results suggested that BA supplementation can improve cognitive function in older adults whose cognitive function at baseline was at or below normal and possibly reduce depression scores.


Assuntos
Cognição , Suplementos Nutricionais , Humanos , Idoso , Afeto , Força da Mão , beta-Alanina , Método Duplo-Cego
2.
Nutrients ; 15(4)2023 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-36839397

RESUMO

ß-alanine is a nonessential amino acid that combines with the amino acid histidine to form the intracellular dipeptide carnosine, an important intracellular buffer. Evidence has been well established on the ability of ß-alanine supplementation to enhance anaerobic skeletal muscle performance. As a result, ß-alanine has become one of the more popular supplements used by competitive athletes. These same benefits have also been reported in soldiers. Evidence accumulated over the last few years has suggested that ß-alanine can result in carnosine elevations in the brain, which appears to have broadened the potential effects that ß-alanine supplementation may have on soldier performance and health. Evidence suggests that ß-alanine supplementation can increase resilience to post-traumatic stress disorder, mild traumatic brain injury and heat stress. The evidence regarding cognitive function is inconclusive but may be more of a function of the stressor that is applied during the assessment period. The potential benefits of ß-alanine supplementation on soldier resiliency are interesting but require additional research using a human model. The purpose of this review is to provide an overview of the physiological role of ß-alanine and why this nutrient may enhance soldier performance.


Assuntos
Carnosina , Militares , Humanos , Carnosina/farmacologia , Exercício Físico/fisiologia , Suplementos Nutricionais , beta-Alanina/farmacologia , Cognição , Músculo Esquelético/metabolismo
3.
Nutrients ; 15(3)2023 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-36771366

RESUMO

Nitric-oxide-stimulating dietary supplements are widely available and marketed to strength athletes and weightlifters seeking to increase muscle performance and augment training adaptations. These supplements contain ingredients classified as nitric oxide (NO) precursors (i.e., "NO boosters"). Endogenous NO is generated via a nitric oxide synthase (NOS)-dependent pathway and a NOS-independent pathway that rely on precursors including L-arginine and nitrates, with L-citrulline serving as an effective precursor of L-arginine. Nitric oxide plays a critical role in endothelial function, promoting relaxation of vascular smooth muscle and subsequent dilation which may favorably impact blood flow and augment mechanisms contributing to skeletal muscle performance, hypertrophy, and strength adaptations. The aim of this review is to describe the NO production pathways and summarize the current literature on the effects of supplementation with NO precursors for strength and power performance. The information will allow for an informed decision when considering the use of L-arginine, L-citrulline, and nitrates to improve muscular function by increasing NO bioavailability.


Assuntos
Citrulina , Óxido Nítrico , Humanos , Óxido Nítrico/metabolismo , Citrulina/farmacologia , Citrulina/metabolismo , Suplementos Nutricionais , Arginina/farmacologia , Arginina/metabolismo , Óxido Nítrico Sintase/metabolismo , Músculo Esquelético/metabolismo , Nitratos/farmacologia
4.
Nutrients ; 14(9)2022 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-35565859

RESUMO

The effect of 3 weeks of amorphous calcium carbonate (ACC) supplementation (2000 mg per day) was examined on the recovery response to resistance exercise. Thirty men were randomized into a supplement (ACC) or placebo (PL) group. Following supplementation, participants performed six sets of 10 repetitions in the bench press (BP) and incline BP exercises, using 80% of maximal strength. Participants returned 24 (T4) and 48 h (T5) later and performed six sets of the BP exercise. Significant decreases in the number of repetitions (p < 0.001), peak power (p < 0.001), and mean power (p = 0.009) were noted over time, but no significant interactions were observed (p > 0.05). Magnitude-based inference analysis (MBI) indicated that the change in repetitions was possibly beneficial for ACC at T4 and likely beneficial at T5. No significant interaction was noted for general soreness (p = 0.452), but a trend toward an interaction was observed in upper body soreness (p = 0.089). Confidence intervals for mean percent change scores indicated significant differences between the groups at T4 and T5, and MBI analysis indicated that ACC was very likely or likely to be beneficial for reducing soreness at those time points. In conclusion, ACC supplementation may have a potential beneficial effect in attenuating the decline in performance, which is possibly due to the carbonate component.


Assuntos
Treinamento Resistido , Carbonato de Cálcio , Suplementos Nutricionais , Método Duplo-Cego , Exercício Físico/fisiologia , Humanos , Masculino , Força Muscular , Músculo Esquelético
5.
J Diet Suppl ; 19(4): 443-458, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33615958

RESUMO

The effect of 30 days of ß-alanine supplementation on neurophysiological responses of animals exposed to an acute heat stress (HS) was examined. Animals were randomized to one of three groups; exposed to HS (120 min at 40-41 °C) and fed a normal diet (EXP; n = 12); EXP and supplemented with ß-alanine (EXP + BA; n = 10); or not exposed (CTL; n = 10). Hippocampal (CA1, CA3 and DG) and hypothalamic (PVN) immunoreactive (ir) cell numbers of COX2, IBA-1, BDNF, NPY and HSP70 were analyzed. Three animals in EXP and one in EXP-BA did not survive the HS, however no significant difference (p = 0.146) was noted in survival rate in EXP + BA. The % change in rectal temperature was significantly lower (p = 0.04) in EXP + BA than EXP. Elevations (p's < 0.05) in COX-2, IBA-1 and HSP70 ir-cell numbers were noted in animals exposed to HS in all subregions. COX-2 ir-cell numbers were attenuated for EXP + BA in CA1 (p = 0.02) and PVN (p = 0.015) compared to EXP. No difference in COX-2 ir-cell numbers was noted between CTL and EXP + BA at CA1. BDNF-ir cell numbers in CA1, DG and PVN were reduced (p's < 0.05) during HS compared to CTL. No difference in BDNF-ir cell numbers was noted between EXP + BA and CTL in CA3 and PVN. NPY-ir density was reduced in exposed animals in all subregions, but NPY-ir density for EXP-BA was greater than EXP in CA3 (p < 0.001) and PVN (p = 0.04). ß-Alanine supplementation attenuated the thermoregulatory and inflammatory responses and maintained neurotrophin and neuropeptide levels during acute HS. Further research is necessary to determine whether ß-alanine supplementation can increase survival rate during a heat stress.


Assuntos
Resposta ao Choque Térmico , beta-Alanina , Animais , beta-Alanina/uso terapêutico , Fator Neurotrófico Derivado do Encéfalo , Ciclo-Oxigenase 2 , Suplementos Nutricionais
6.
J Diet Suppl ; 18(2): 147-168, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32138563

RESUMO

Introduction: ß-alanine (BA) supplementation may improve cognition and mitigate symptoms of anxiety and depression associated with aging, neurological disorders, and physical exertion, which has been attributed to increases in brain carnosine and/or brain-derived neurotropic factor (BDNF). BA also provides beneficial effects on cognition, mood, and physical performance during military operations; however, whether BA can attenuate mood disruptions and cognitive dysfunction associated with the anticipatory stress prior to simulated military operations is unknown.Purpose: The present study examined the effects of 14 days of BA (12 g·day-1) supplementation on cognitive function, mood, and circulating BDNF concentrations in recreationally-active, healthy males with limited inflammation and oxidative stress prior to a 24h simulated military operation.Methods: Participants were randomized into BA (n = 10) or placebo (n = 9; PL) for 14 days. Cognitive function, mood, and circulating BDNF were assessed before (PRE) and after (POST) supplementation. Cognition was assessed via multiple object tracking (Neurotracker™), visuomotor reaction time (Dynavision™), mathematical processing (Serial Subtraction Test), and neuropsychological assessments (ANAM™). Mood was assessed using the Profile of Mood States (POMS) questionnaire. After POST testing, subjects underwent a 24h simulated military operation.Results: No change in measures of cognitive function or BDNF concentrations were observed (p > 0.05). However, BA experienced significant reductions (p = 0.046) in subjective feelings of depression, while PL experienced significant reductions (p = 0.021) in feelings of vigor from PRE to POST.Conclusions: High-dose, short-duration BA supplementation does not appear to affect cognitive function or circulating BDNF, but may mitigate the onset of negative mood states in healthy, recreationally-active males prior to a simulated military operation.


Assuntos
Afeto/efeitos dos fármacos , Fator Neurotrófico Derivado do Encéfalo , Cognição , Militares , Estresse Psicológico , beta-Alanina/administração & dosagem , Encéfalo , Fator Neurotrófico Derivado do Encéfalo/sangue , Cognição/efeitos dos fármacos , Suplementos Nutricionais , Humanos , Masculino
7.
J Strength Cond Res ; 34(11): 3042-3054, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33105353

RESUMO

Wells, AJ, Varanoske, AN, Coker, NA, Kozlowski, GJ, Frosti, CL, Boffey, D, Harat, I, Jahani, S, Gepner, Y, and Hoffman, JR. Effect of ß-alanine supplementation on monocyte recruitment and cognition during a 24-hour simulated military operation. J Strength Cond Res 34(11): 3042-3054, 2020-Sustained military operations (SUSOPs) result in psychological stress and cognitive dysfunction, which may be related to the recruitment of classical monocytes into the brain. This study examined the effect of beta-alanine (BA) on cognition and monocyte recruitment during a simulated 24-hour SUSOP. Nineteen healthy men ingested 12-g/d BA or placebo for 14 days before an SUSOP. Monocyte chemoattractant protein-1 (MCP-1), C-C chemokine receptor-2 (CCR2), and macrophage-1-antigen (CD11b) expression were assessed through multiplex assay and flow cytometry. Psychological stress and cognition were assessed through Automated Neuropsychological Assessment Metrics (ANAM). A composite measure of cognition (COGcomp) was generated from throughput scores extracted from 7 ANAM cognitive tests. Assessments occurred at baseline (0H), 12 hours (12H), 18 hours (18H), and 24 hours (24H). Significance was accepted at p ≤ 0.05. No significant effect of BA was noted for any variable (p's > 0.05). The frequency and severity of symptoms of psychological stress increased significantly at 18 and 24H compared with 0 and 12H (p's < 0.05). COGcomp decreased significantly at 18 and 24H compared with 0 and 12H (p's ≤ 0.001). MCP-1 peaked at 18H was significantly lower at 24H compared with 18H but remained elevated at 24H compared with 0H (p's < 0.001). CCR2 expression was significantly lower at 12 (p = 0.031), 18, and 24H (p's < 0.001). CD11b expression was significantly higher at 12H (p = 0.039) and 24H (p's = 0.003). MCP-1 was negatively associated with COGcomp (ß = -0.395, p = 0.002, r2 = 0.174). Neither CCR2 or CD11b was related to COGcomp (p's > 0.05). Cognitive dysfunction during SUSOPs is related to serum concentrations of MCP-1 but is not influenced by BA supplementation.


Assuntos
Cognição/efeitos dos fármacos , Militares , Monócitos/efeitos dos fármacos , Estresse Psicológico/fisiopatologia , beta-Alanina/farmacologia , Adulto , Quimiocina CCL2/biossíntese , Suplementos Nutricionais , Método Duplo-Cego , Humanos , Antígeno de Macrófago 1/biossíntese , Masculino , Monócitos/imunologia , Receptores CCR2/biossíntese , Treinamento por Simulação/métodos , Estresse Psicológico/epidemiologia , Adulto Jovem
8.
J Strength Cond Res ; 34(9): 2476-2481, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32740286

RESUMO

Hoffman, JR, Marcus, I, Dubnov-Raz, G, and Gepner, Y. Ergogenic effects of 8 days of Sceletium tortuosum supplementation on mood, visual tracking, and reaction in recreationally trained men and women. J Strength Cond Res 34(9): 2476-2481, 2020-Sceletium tortuosum (ST) is a South African plant that has been reported to promote a sense of well-being in healthy individuals and used in treating people with anxiety, stress, or depression. These studies have been conducted in middle-aged and older adults, but no investigations have been performed in a healthy, young adult population. Thus, the purpose of this study was to examine the effect of 8 days of ST extract (25-mg) supplementation on changes in reactive agility, visual tracking, and mood. Sixty recreationally trained men (n = 48) and women (n = 12), between 20 and 35 years, were randomly assigned to 1 of 2 groups: ST or placebo (PL). Subjects were tested on 2 occasions: before supplementation and 2-hours after supplementation on day 8. Subjects completed a subjective questionnaire to assess alertness and energy using a visual analog scale (VAS). In addition, subjects completed the Profile of Mood States questionnaire and performed reactive agility and visual tracking assessments. Significant improvements were noted for ST in complex reactive performance that required subjects to respond to repeated visual stimuli with a cognitive load compared with PL. However, no significant changes were noted between the groups in either VAS or total mood score. In addition, no differences were observed in simple reaction assessments. The results of this study demonstrate an ergogenic benefit in complex reactive tasks that include a cognitive load. However, in this subject population studied, no benefits in mood were observed.


Assuntos
Afeto/efeitos dos fármacos , Movimentos Oculares/efeitos dos fármacos , Medicinas Tradicionais Africanas/métodos , Extratos Vegetais/farmacologia , Plantas Medicinais , Tempo de Reação/efeitos dos fármacos , Adulto , Método Duplo-Cego , Feminino , Humanos , Masculino , Substâncias para Melhoria do Desempenho/farmacologia , Adulto Jovem
9.
J Strength Cond Res ; 33(9): 2330-2337, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31306390

RESUMO

Hoffman, JR, Hoffman, MW, Zelicha, H, Gepner, Y, Willoughby, DS, Feinstein, U, and Ostfeld, I. The Effect of 2-Weeks of Inactivated Probiotic Bacillus coagulans on Endocrine, Inflammatory and Performance Responses During Self-Defense Training in Soldiers. J Strength Cond Res 33(9): 2330-2337, 2019-The effect of 2 weeks of inactivated Bacillus coagulans (iBC) ingestion on performance and inflammatory cytokines was examined during a self-defense course in soldiers. Sixteen male soldiers were randomly assigned to either iBC (n = 8) or placebo (PL; n = 8) in this double-blind study. Participants were garrisoned on base and participated in the same training tasks. Assessments were conducted in a single day before (PRE) and after the supplementation period (POST). During each testing session, participants were assessed for vertical jump power (VJP), muscle endurance, simulated casualty drag, and 2 100-m shuttle runs. Resting blood measures for testosterone, cortisol, creatine kinase, and inflammatory cytokines were also assessed. Mann-Whitney analysis of change (Δ) scores indicated no significant change (p's > 0.05) in any of the performance or blood variables. However, a trend (p = 0.089) was noted in the Δ score for VJP in iBC compared with PL. In addition, trends were observed in the change in IL-10 (p = 0.057) and IFNγ (p = 0.057). Magnitude based inferential analysis indicated that changes in VJP and simulated casualty drag were likely beneficial (90.7 and 80.4% likelihood effect, respectively) for iBC. In addition, iBC supplementation very likely augmented IL-10 concentrations, but was possibly negative for changes in IL-6, and likely negative for changes in TNFα and IFNγ. Changes in all other performance and blood markers were unclear. Results indicated that 2 weeks of iBC supplementation appeared to be beneficial for maintaining power and short-term speed performance, while attenuating the inflammatory response during intense training in a military self-defense course.


Assuntos
Bacillus coagulans , Citocinas/sangue , Exercício Físico/fisiologia , Artes Marciais/fisiologia , Militares , Probióticos/farmacologia , Creatina Quinase/sangue , Método Duplo-Cego , Humanos , Hidrocortisona/sangue , Inflamação/sangue , Interferon gama/sangue , Interleucina-10/sangue , Interleucina-6/sangue , Israel , Masculino , Artes Marciais/educação , Força Muscular/efeitos dos fármacos , Resistência Física/efeitos dos fármacos , Corrida , Testosterona/sangue , Fator de Necrose Tumoral alfa/sangue , Adulto Jovem
10.
Appl Physiol Nutr Metab ; 44(10): 1112-1115, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30998856

RESUMO

Carnosine and histidine content in the hippocampus of 14-month-old male rats was examined following 30 days of ß-alanine supplementation. All animals were provided identical diets; however, 100 mg of ß-alanine was mixed with glucomannan (80:20 blend) in the water of ß-alanine supplemented animals. Hippocampal carnosine content was significantly greater (p = 0.005) for ß-alanine compared with control, while no differences (p = 0.438) were noted in histidine content between groups. Results provide initial evidence that ß-alanine supplementation increases carnosine content in the hippocampus of middle-aged rats, without compromising histidine content. ß-Alanine supplementation increases hippocampal carnosine content without compromising histidine content in middle-aged rats.


Assuntos
Carnosina/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Histidina/metabolismo , beta-Alanina/farmacologia , Animais , Suplementos Nutricionais , Masculino , Ratos , Ratos Sprague-Dawley
11.
Nutr Res ; 62: 51-63, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30803507

RESUMO

The effect of 30 days of ß-alanine supplementation (100 mg/kg) on behavioral response and expression of brain-derived neurotrophic factor (BDNF), neuropeptide Y (NPY), and markers of inflammation was examined in both young (4 months) and older (14 months) rats. We hypothesized that animals fed ß-alanine would experience reduced inflammation and an enhanced neurotrophin and behavioral response. Animals were assigned to either a control group, in which young or older rats were fed regular chow and water, or a ß-alanine group, in which rats were fed regular chow and provided ß-alanine in their water. Behavior measures were conducted following the 30-day supplementation period, which included spatial learning, memory, and an anxiety index. Hippocampal expressions of BDNF, NPY, glial fibrillary acidic protein, nuclear factor-κB p50 and p65 subunits, tumor necrosis factor-α, and cyclooxygenase-2 were also analyzed. Learning ability was reduced (P = .001) and anxiety index was higher (P = .001) in older compared to young rats. Similarly, BDNF and NPY expressions were reduced and all inflammatory markers were elevated (P < .05) in the older animals. ß-Alanine increased BDNF expressions in the cornu ammonis area 1 (P = .003) and 3 (P < .001) subregions of the hippocampus. BDNF expression for younger rats in the ß-alanine group was also significantly greater than younger rats in the control group in cornu ammonis area 3. Learning for young animals fed ß-alanine was significantly better than all other groups. Significant reductions in anxiety were noted in both older and younger rats fed ß-alanine compared to age-matched controls. Results indicated that ß-alanine ingestion in both young and older rats was effective in attenuating anxiety and augmenting BDNF expression in the hippocampus.


Assuntos
Ansiedade/tratamento farmacológico , Fator Neurotrófico Derivado do Encéfalo/efeitos dos fármacos , Suplementos Nutricionais , beta-Alanina/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Masculino , Fatores de Crescimento Neural/efeitos dos fármacos , Fatores de Crescimento Neural/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , beta-Alanina/administração & dosagem
12.
Amino Acids ; 51(1): 49-60, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30003336

RESUMO

ß-alanine supplementation increases muscle carnosine content and improves anaerobic exercise performance by enhancing intracellular buffering capacity. ß-alanine ingestion in its traditional rapid-release formulation (RR) is associated with the symptoms of paresthesia. A sustained-release formulation (SR) of ß-alanine has been shown to circumvent paresthesia and extend the period of supply to muscle for carnosine synthesis. The purpose of this investigation was to compare 28 days of SR and RR formulations of ß-alanine (6 g day-1) on changes in carnosine content of the vastus lateralis and muscle fatigue. Thirty-nine recreationally active men and women were assigned to one of the three groups: SR, RR, or placebo (PLA). Participants supplementing with SR and RR formulations increased muscle carnosine content by 50.1% (3.87 mmol kg-1ww) and 37.9% (2.62 mmol kg-1ww), respectively. The change in muscle carnosine content in participants consuming SR was significantly different (p = 0.010) from those consuming PLA, but no significant difference was noted between RR and PLA (p = 0.077). Although participants ingesting SR experienced a 16.4% greater increase in muscle carnosine than RR, fatigue during maximal voluntary isometric contractions was significantly attenuated in both SR and RR compared to PLA (p = 0.002 and 0.024, respectively). Symptoms of paresthesia were significantly more frequent in RR compared to SR, the latter of which did not differ from PLA. Results of this study demonstrated that only participants consuming the SR formulation experienced a significant increase in muscle carnosine. Differences in the muscle carnosine response between these formulations may have practical significance for athletic populations in which small changes may have important implications on performance.


Assuntos
Carnosina/biossíntese , Preparações de Ação Retardada/administração & dosagem , Suplementos Nutricionais , Músculo Esquelético/efeitos dos fármacos , Parestesia/prevenção & controle , beta-Alanina/administração & dosagem , Adulto , Carnosina/agonistas , Método Duplo-Cego , Esquema de Medicação , Exercício Físico , Feminino , Humanos , Contração Isométrica/efeitos dos fármacos , Masculino , Fadiga Muscular/efeitos dos fármacos , Fadiga Muscular/fisiologia , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiologia , Parestesia/metabolismo , Parestesia/fisiopatologia
13.
Res Sports Med ; 27(2): 204-218, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30348016

RESUMO

ß-Hydroxy-ß-Methylbutyrate (HMB) is a metabolite of the branched-chain amino acid leucine and its ketoacid α-ketoisocaproate. HMB has been widely used as an ergogenic supplement to increase muscle strength, muscle hypertrophy and enhance recovery. The physiological mechanisms that underlie these benefits are related to HMB's ability to stimulate muscle protein synthesis and minimize muscle breakdown. Although evidence supporting the benefits of HMB supplementation is not conclusive, many of these studies have suffered from methodological flaws including different formulations, supplement duration and population studied. HMB in its free acid formulation is suggestive of having a greater potential for efficacy in both trained and untrained populations than its calcium-salt form. However, the evidence regarding HMB's role in limiting muscle degradation and increasing muscle protein synthesis has created an exciting interest in examining its efficacy among untrained individuals. Recent investigations examining intense training have demonstrated efficacy in maintaining muscle mass and attenuating the inflammatory response.


Assuntos
Desempenho Atlético/fisiologia , Músculo Esquelético/efeitos dos fármacos , Fenômenos Fisiológicos da Nutrição Esportiva/efeitos dos fármacos , Fenômenos Fisiológicos da Nutrição Esportiva/fisiologia , Valeratos/administração & dosagem , Aminoácidos Essenciais/administração & dosagem , Atletas , Composição Corporal/efeitos dos fármacos , Suplementos Nutricionais , Humanos , Leucina/administração & dosagem , Desenvolvimento Muscular/efeitos dos fármacos , Força Muscular/efeitos dos fármacos
14.
J Am Coll Nutr ; 38(2): 149-161, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30277420

RESUMO

OBJECTIVE: The present study evaluated the effects of repeated-sprint training in normobaric hypoxia and ß-alanine supplementation (BA) on aerobic and anaerobic performance in recreationally active men. METHODS: Participants were randomly assigned to one of the following groups: normoxia/ß-alanine (NB, n = 11), normoxia/placebo (NP, n = 8), normobaric hypoxia/ß-alanine (HB, n = 10) and normobaric hypoxia/placebo (HP, n = 9). All participants completed 8 training sessions over 4 weeks on a cycle ergometer either in normobaric hypoxia (oxygen fraction: FiO2 = 14.2%) or normoxia (FiO2 = 20.9%). Participants were instructed to consume a daily dosage of 6.4 g of BA or placebo. Changes in performance in a graded exercise test, repeated-sprint test (RST), and 3-minute all-out test (3MT) were examined before and after training and supplementation. RESULTS: No between-group differences were observed for training volume or supplementation compliance. Anthropometric and hematological measures remained unchanged before and after intervention in all groups. A main effect of training condition was shown for oxygen consumption and power output at respiratory compensation point, average power output during the last sprint of the RST, heart rate recovery following the RST, and total work during the 3MT. These measures in the normobaric hypoxia groups were significantly (p < 0.05) higher than the normoxia groups, except for the heart rate recovery following the RST. A main effect of supplement was detected in anaerobic working capacity, with postintervention values in the BA groups being significantly (p < 0.05) higher than the placebo groups. CONCLUSIONS: Repeated-sprint training in hypoxia improved aerobic performance, exercise tolerance, cardiovascular recovery, and overall working capacity, while BA maintained the anaerobic working capacity. However, BA did not provide additional benefits with respect to attenuating fatigue or enhancing repeated-sprint performance.


Assuntos
Desempenho Atlético/fisiologia , Suplementos Nutricionais , Treinamento Intervalado de Alta Intensidade/métodos , Hipóxia/fisiopatologia , beta-Alanina/farmacologia , Adulto , Ciclismo/fisiologia , Teste de Esforço , Tolerância ao Exercício/efeitos dos fármacos , Voluntários Saudáveis , Humanos , Hipóxia/terapia , Masculino , Consumo de Oxigênio , Corrida/fisiologia , Adulto Jovem
15.
Physiol Rep ; 6(24): e13938, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30565426

RESUMO

Sustained military operations (SUSOPs) are associated with performance decrements and cognitive dysfunction. ß-Alanine (BA) supplementation may have a role in increasing soldier resiliency by enhancing muscle-buffering capacity and reducing oxidative stress. The purpose of this study was to examine the effects of BA on physical performance, cognition, endocrine function, and inflammation during a 24 h simulated SUSOP. Nineteen males were randomized into one of two groups: BA (n = 10) or placebo (n = 9; PLA) (12 g/day) for 14 days preceding the 24 h SUSOP. Assessments were performed at 0 h (0H), 12 h (12H), and 24 h (24H) during the SUSOP. No changes in visual tracking ability, jump power, or upper-body muscular endurance were observed between groups or time points (P's > 0.05). Increases in subjective feelings of soreness and fatigue were noted at 12H compared to 0H (P < 0.05) in PLA, but not in BA. Visual reaction time for PLA was slower at 24H compared to 0H (P = 0.035), and PLA made more errors on reaction time testing at 12H compared to BA (P = 0.048), but motor reaction time was faster (P = 0.016) for PLA. Simulated litter carry and 1 km run completion times increased at 24H compared to 0H in both groups (P < 0.05), however, PLA had a longer 1 km time compared to BA at 24H (P = 0.050). Increases in inflammatory and endocrine markers were observed over the SUSOP, with no differences between groups. BA supplementation appears to maintain some aspects of cognition and physical performance during a 24 h SUSOP, with no effects on endocrine function or inflammation.


Assuntos
Anti-Inflamatórios/farmacologia , Cognição/efeitos dos fármacos , Hidrocortisona/sangue , Militares , Resistência Física/efeitos dos fármacos , Testosterona/sangue , beta-Alanina/farmacologia , Adolescente , Adulto , Anti-Inflamatórios/administração & dosagem , Humanos , Masculino , Fadiga Muscular/efeitos dos fármacos , beta-Alanina/administração & dosagem
16.
J Spec Oper Med ; 18(4): 92-96, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30566730

RESUMO

We examined the effect of a proprietary spearmint extract containing rosmarinic acid (PSE) on physical, cognitive, and executive functioning of study participants after a high-risk tactical operation while sleep deprived for 24 hours. Ten Operators (mean ± standard deviation: age, 35.1 ± 5.2 years; height, 177.6 ± 5.3cm; weight, 81.3 ± 9.3kg) from an elite counterterrorism unit volunteered to participate in this randomized, double-blind, parallel-design study. Participants were randomly assigned into either the PSE or placebo (PL) group and ingested 900mg/day PSE or an equivalent amount of PL for 17 days. Physical, cognitive, and executive functioning was tested before PST supplementation (PRE) and within 1 hour of the operation's conclusion (POST). Magnitude-based inferences indicated that differences between PSE and PL in jump power, reactive agility, eye-hand coordination, and cognition were unclear. However, subjective feelings of energy, alertness, and focus were very likely, likely, and possibly better for PSE than PL, respectively. There was no difference (ρ = .64) between groups in identifying the correct target; however, all participants in the PSE group correctly identified the target, whereas 60% of participants in the PL group correctly identified the target at POST. Although the results of this study do not provide conclusive evidence regarding the efficacy of PSE, they do suggest additional research is warranted in a larger sample of participants.


Assuntos
Cinamatos/farmacologia , Depsídeos/farmacologia , Função Executiva/efeitos dos fármacos , Mentha spicata , Militares/psicologia , Desempenho Físico Funcional , Extratos Vegetais/farmacologia , Guerra , Adulto , Método Duplo-Cego , Humanos , Militares/estatística & dados numéricos , Ácido Rosmarínico
17.
Med Sci Sports Exerc ; 50(11): 2231-2241, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29957728

RESUMO

PURPOSE: To examine the impact of polyphenol supplementation on the recruitment, mobilization, and activation of monocyte subsets after resistance exercise. METHODS: Thirty-eight recreationally active males (22.1 ± 3.1 yr; 173.9 ± 7.9 cm; 77.8 ± 14.5 kg) were assigned to 28 d of polyphenol blend (PPB) supplementation, placebo (PL), or control (CON). Blood samples were obtained before (PRE) postresistance exercise, immediately (IP) postresistance exercise, 1 h (1H) postresistance exercise, 5 h (5H) postresistance exercise, 24 h (24H) postresistance exercise, and 48 h (48H) postresistance exercise (PPB/PL) or rest (CON). Fine-needle biopsies were obtained from the vastus lateralis at PRE, 1H, 5H, and 48H. Circulating concentrations of macrophage chemoattractant protein-1 (MCP-1) and fractalkine, as well as intramuscular MCP-1 were analyzed via multiplex assay. Changes in the proportions and expression of CD11b on monocyte subsets were assessed via flow cytometry. RESULTS: Circulating MCP-1 increased in PPB and PL at IP with further increases at 5H. Intramuscular MCP-1 was increased at 1H, 5H, and 48H in all groups. Classical monocyte proportions were reduced in PPB and PL at IP, and increased at 1H. Nonclassical monocytes were increased in PPB and PL at IP, whereas intermediate monocytes were increased at IP, and reduced at 1H. Intermediate monocytes were increased in PPB at 24H and 48H. CD11b expression was reduced on PPB compared with PL and CON at PRE on intermediate and nonclassical monocytes. CONCLUSIONS: Resistance exercise may elicit selective mobilization of intermediate monocytes at 24H and 48H, which may be mediated by tissue damage. Additionally, polyphenol supplementation may suppress CD11b expression on monocyte subsets at rest.


Assuntos
Antioxidantes/administração & dosagem , Suplementos Nutricionais , Monócitos/metabolismo , Polifenóis/administração & dosagem , Músculo Quadríceps/metabolismo , Treinamento Resistido , Antígeno CD11b/sangue , Quimiocina CCL2/sangue , Quimiocina CCL2/metabolismo , Quimiocina CX3CL1/sangue , Humanos , Antígeno de Macrófago 1/sangue , Masculino , Fatores de Tempo , Adulto Jovem
18.
J Strength Cond Res ; 32(10): 2978-2981, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29746388

RESUMO

Hoffman, JR, Gepner, Y, Hoffman, M, Zelicha, H, Shapira, S, and Ostfeld, I. Effect of high dose, short-duration ß-alanine supplementation on circulating IL-10 concentrations during intense military training. J Strength Cond Res 32(10): 2978-2981, 2018-This study examined the effect of ß-alanine as a potential anti-inflammatory agent during intense military training. Twenty soldiers (20.1 ± 0.6 years) from an elite combat unit were randomly assigned to either a ß-Alanine (BA) or placebo (PL) group. Soldiers were provided with 12 g·d of either BA or PL for 7 days between 2 intensive periods of navigational training and restricted sleep. During the initial training period, soldiers navigated on average 27.8 km·d with ∼50% of their body mass in their packs for 5 days. Soldiers returned to base and began a 7-day supplementation program before departing for an additional period of intense field training. During the second period of field training, soldiers navigated 10 km·d for an additional 5 days, carrying similar loading as the initial week, performed tactical missions, and slept approximately 5 hours per day. Blood samples were obtained after the initial training period and after the second training period and analyzed for IL-10. Magnitude-based inferences that were used to provide inferences on the true effect BA may have had on IL-10 concentrations compared with PL, calculated from 90% confidence intervals. Data analysis indicated that changes in circulating IL-10 concentrations (mean difference 0.86 pg·ml) were possibly greater (57%) for BA than PL. Results of this study suggest that 1 week of high-dose BA ingestion may enhance the anti-inflammatory response during intense military training, suggesting a potential therapeutic role of BA during intense training.


Assuntos
Anti-Inflamatórios/administração & dosagem , Suplementos Nutricionais , Exercício Físico , Interleucina-10/sangue , Militares , beta-Alanina/administração & dosagem , Método Duplo-Cego , Humanos , Israel , Masculino , Adulto Jovem
19.
Adv Food Nutr Res ; 84: 183-206, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29555069

RESUMO

ß-Alanine is one of the more popular sport supplements used by strength/power athletes today. The popularity of ß-alanine stems from its ability to enhance intracellular muscle-buffering capacity thereby delaying fatigue during high-intensity exercise by increasing muscle carnosine content. Recent evidence also suggests that elevated carnosine levels may enhance cognitive performance and increase resiliency to stress. These benefits are thought to result from carnosine's potential role as an antioxidant. This review will discuss these new findings including recent investigations examining ß-alanine supplementation and increased resiliency to posttraumatic stress and mild traumatic brain injury. This review will focus on the physiology of carnosine, the effect of ß-alanine ingestion on carnosine elevations, and the potential ergogenic benefits it has for competitive and tactical athletes.


Assuntos
Carnosina/metabolismo , Suplementos Nutricionais , beta-Alanina/farmacologia , Antioxidantes/administração & dosagem , Antioxidantes/farmacocinética , Antioxidantes/farmacologia , Interações Medicamentosas , Exercício Físico/fisiologia , Humanos , beta-Alanina/administração & dosagem , beta-Alanina/farmacocinética
20.
Physiol Rep ; 6(2)2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29380956

RESUMO

The purpose of this study was to examine the effects of 28-days of supplementation with an aqueous proprietary polyphenol blend (PPB) sourced from Camellia sinensis on intramuscular apoptotic signaling following an acute lower-body resistance exercise protocol and subsequent recovery. Untrained males (n = 38, 21.8 ± 2.7 years, 173.4 ± 7.9 cm, 77.6 ± 14.6 kg) were randomized to PPB (n = 14), placebo (PL; n = 14) or control (CON; n = 10). Participants completed a lower-body resistance exercise protocol comprised of the squat, leg press, and leg extension exercises. Skeletal muscle microbiopsies were obtained from the vastus lateralis preexercise (PRE), 1-h (1HR), 5-h (5HR), and 48-h (48HR) post-resistance exercise. Apoptotic signaling pathways were quantified using multiplex signaling assay kits to quantify total proteins (Caspase 3, 8, 9) and markers of phosphorylation status (JNK, FADD, p53, BAD, Bcl-2). Changes in markers of muscle damage and intramuscular signaling were analyzed via separate repeated measures analysis of variance (ANOVA). Change in Bcl-2 phosphorylation at 1H was significantly greater in PL compared to CON (P = 0.001). BAD phosphorylation was significantly elevated at 5H in PL compared to PPB (P = 0.015) and CON (P = 0.006). The change in JNK phosphorylation was significantly greater in PPB (P = 0.009), and PL (P = 0.017) compared to CON at 1H, while the change for PL was elevated compared to CON at 5H (P = 0.002). A main effect was observed (P < 0.05) at 1H, 5H, and 48H for p53 and Caspase 8, with Caspase 3 and Caspase 9 elevated at 48H. These data indicate that chronic supplementation with PPB alters apoptotic signaling in skeletal muscle following acute muscle-damaging resistance exercise.


Assuntos
Suplementos Nutricionais , Músculo Esquelético/fisiologia , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Treinamento Resistido , Apoptose/fisiologia , Humanos , Masculino , Adulto Jovem
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