RESUMEN
Betaine supplementation is used by athletes, but its mechanism of action is still not fully understood. We hypothesized that betaine supplementation would increase betaine concentration and alter amino acid profiles in relation to MTHFR genotype and dose in physically active males. The study followed a randomized placebo-controlled cross-over design. Blood samples were collected before and after each supplementation period. Serum was analyzed for amino acid profile, homocysteine, betaine, choline, and trimethylamine N-oxide (TMAO) concentrations. For the washout analysis, only participants starting with betaine were included (n = 20). Statistical analysis revealed no differences in the amino acid profile after betaine supplementation. However, betaine concentration significantly increased after betaine supplementation (from 4.89 ± 1.59 µg/mL to 17.31 ± 9.21 µg/mL, P < .001), with a greater increase observed in MTHFR (C677T, rs180113) T-allele carriers compared to CC (P = .027). Betaine supplementation caused a decrease in homocysteine concentration (from 17.04 ± 4.13 µmol/L to 15.44 ± 3.48 µmol/L, P = .00005) and a non-significant increase in TMAO concentrations (from 0.27 ± 0.20 µg/ml to 0.44 ± 0.70 µg/ml, P = .053), but had no effect on choline concentrations. Serum betaine concentrations were not significantly different after the 21-day washout from the baseline values (baseline: 4.93 ± 1.87 µg/mL and after washout: 4.70 ± 1.70 µg/mL, P = 1.000). In conclusion, betaine supplementation increased betaine and decreased homocysteine concentrations, but did not affect the amino acid profile or choline concentrations in healthy active males. Betaine concentrations may be dependent on MTHFR genotype.
Asunto(s)
Aminoácidos , Betaína , Colina , Estudios Cruzados , Suplementos Dietéticos , Genotipo , Metilenotetrahidrofolato Reductasa (NADPH2) , Humanos , Betaína/sangre , Masculino , Metilenotetrahidrofolato Reductasa (NADPH2)/genética , Aminoácidos/sangre , Adulto , Adulto Joven , Colina/sangre , Homocisteína/sangre , Metilaminas/sangreRESUMEN
BACKGROUND: Caffeine (CAF) ingestion improves performance in a broad range of exercise tasks. Nevertheless, the CAF-induced, dose-dependent effect on discipline-specific performance and cognitive functions in CrossFit/High-Intensity Functional Training (HIFT) has not been sufficiently investigated. The aim of this study was to evaluate the effect of acute supplementation of three different doses of CAF and placebo (PLA) on specific performance, reaction time (RTime), postural stability (PStab), heart rate (HR) and perceived exertion (RPE). METHODS: In a randomized double-blind placebo-controlled crossover design, acute pre-exercise supplementation with CAF (3, 6, or 9 mg/kg body mass (BM)) and PLA in 26 moderately trained CrossFit practitioners was examined. The study protocol involved five separate testing sessions using the Fight Gone Bad test (FGB) as the exercise performance evaluation and biochemical analyses, HR and RPE monitoring, as well as the assessment of RTime and PStab, with regard to CYP1A2 (rs762551) and ADORA2A (rs5751876) single nucleotide polymorphism (SNP). RESULTS: Supplementation of 6 mgCAF/kgBM induced clinically noticeable improvements in FGBTotal results, RTime and pre-exercise motor time. Nevertheless, there were no significant differences between any CAF doses and PLA in FGBTotal, HRmax, HRmean, RPE, pre/post-exercise RTime, PStab variables or pyruvate concentrations. Lactate concentration was higher (p < 0.05) before and after exercise in all CAF doses than in PLA. There was no effect of CYP1A2 or ADORA2A SNPs on performance. CONCLUSIONS: The dose-dependent effect of CAF supplementation appears to be limited to statistically nonsignificant but clinically considered changes on specific performance, RTime, PStab, RPE or HR. However, regarding practical CAF-induced performance implications in CrossFit/HIFT, 6 mgCAF/kgBM may be supposed as the most rational supplementation strategy.
Asunto(s)
Rendimiento Atlético , Cafeína , Humanos , Cafeína/farmacología , Estudios Cruzados , Citocromo P-450 CYP1A2 , Tiempo de Reacción , Rendimiento Atlético/fisiología , Ácido Láctico , Método Doble Ciego , Suplementos Dietéticos , PoliésteresRESUMEN
BACKGROUND: Because betaine (BET) supplementation may improve muscular strength and endurance, it seems plausible that BET will also influence CrossFit performance (CF). PURPOSE: The aim of this study was to evaluate the effects of three weeks of BET supplementation on body composition, CF performance, muscle power in the Wingate anaerobic test (WAnT), and the concentrations of selected hormones. The secondary aims were to analyze the effectiveness of two different BET doses (2.5 and 5.0 g/d) and their interaction with the methylenetetrahydrofolate reductase (MTHFR) genotype. METHODS: The study was designed in a double-blinded randomized cross-over fashion. Forty-three CF practitioners completed the entire study. CF performance was measured using the Fight Gone Bad (FGB) workout and muscle power was evaluated in a 30-second WAnT. Body composition was determined by air-displacement plethysmography. Blood was drawn to assess hormone concentrations. The C677T single nucleotide polymorphism (rs180113) in the MTHFR gene was analyzed. RESULTS: FGB total improved with BET by 8.7 ± 13.6% (p < 0.001), but no significant changes were observed with placebo (- 0.4 ± 10.0%, p = 0.128). No changes were also observed in WAnT and body composition. After BET supplementation testosterone concentration increased by 7.0 ± 15.4% with BET (p = 0.046) (no change with placebo: 1.5 ± 19.6%, p = 0.884) but had no effect on concentrations of insulin-like growth factor or cortisol. Finally, there were no significant interactions between MTHFR genotype and BET dose in any outcome. CONCLUSIONS: BET supplementation may improve CF performance and increase testosterone concentration. However, there was no evidence of a difference between dosages (2.5 and 5.0 g/d) and MTHFR genotypes. The trial was registered on clinicaltrials.gov (NCT03702205) on 10 October 2018.
Asunto(s)
Betaína , Testosterona , Humanos , Betaína/farmacología , Estudios Cruzados , Método Doble Ciego , Suplementos DietéticosRESUMEN
The purpose of this investigation was to compare the impacts of a potential blood flow restriction (BFR)-betaine synergy on one-leg press performance, lactate concentrations, and exercise-associated biomarkers. Eighteen recreationally trained males (25 ± 5 y) were randomized to supplement 6 g/day of either betaine anhydrous (BET) or cellulose placebo (PLA) for 14 days. Subsequently, subjects performed four standardized sets of one-leg press and two additional sets to muscular failure on both legs (BFR [LL-BFR; 20% 1RM at 80% arterial occlusion pressure] and high-load [HL; 70% 1RM]). Toe-tip lactate concentrations were sampled before (PRE), as well as immediately (POST0), 30 min (POST30M), and 3 h (POST3H) post-exercise. Serum homocysteine (HCY), growth hormone (GH) and insulin-like growth factor-1 concentrations were additionally assessed at PRE and POST30M. Analysis failed to detect any significant between-supplement differences for total repetitions completed. Baseline lactate changes (∆) were significantly elevated from POST0 to POST30 and from POST30 to POST3H (p < 0.05), whereby HL additionally demonstrated significantly higher ∆Lactate versus LL-BFR (p < 0.001) at POST3H. Although serum ∆GH was not significantly impacted by supplement or condition, serum ∆IGF-1 was significantly (p = 0.042) higher in BET versus PLA and serum ∆HCY was greater in HL relative to LL-BFR (p = 0.044). Although these data fail to support a BFR-betaine synergy, they otherwise support betaine's anabolic potential.
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Entrenamiento de Fuerza , Humanos , Masculino , Betaína/metabolismo , Biomarcadores/metabolismo , Terapia de Restricción del Flujo Sanguíneo , Expresión Génica , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Ácido Láctico/metabolismo , Músculo Esquelético/metabolismo , Flujo Sanguíneo Regional , Adulto Joven , AdultoRESUMEN
Betaine (BET) supplementation decreases homocysteine concentration in plasma, but it may also have an adverse effect on health by increasing blood lipid concentrations, at least in overweight and obese individuals. The aim of this study was to evaluate the effect of BET supplementation on the lipid profile and concentrations of homocysteine, inflammatory cytokines, and liver enzymes in physically active, healthy males. This was a randomized, placebo (PL)-controlled, double-blinded, crossover trial. BET (2.5 or 5.0 g/d) was administered for 21 days. Before and after supplementation with BET or PL, anthropometric measurements and blood were collected in a fasted state. Our results show that BET supplementation significantly decreased homocysteine concentration (from 17.1 ± 4.0 µmol/L before BET to 15.6 ± 3.5 µmol/L after BET, p = 0.009, η2 = 0.164). However, the intervention had no effect on total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triacylglycerol, interleukins 1ß and 6, and tumour necrosis factor α concentrations, or alanine and aspartate activities. In addition, there were no interactions between the MTHFR genotype and BET dose. In conclusion, BET supplementation may be beneficial for homocysteine concentration in healthy, physically active males, with no detrimental effect on lipid profile.
RESUMEN
Several previous investigations have employed betaine supplementation in randomized controlled crossover designs to assess its ostensible ergogenic potential. Nevertheless, prior methodology is predicated on limited pharmacokinetic data and an appropriate betaine-specific washout period is hitherto undescribed. The purpose of the present pilot investigation was therein to determine whether a 28 day washout period was sufficient to return serum betaine concentrations to baseline following a supplementation protocol. Five resistance-trained men (26 ± 6 y) supplemented with 6 g/day betaine anhydrous for 14 days and subsequently visited the lab 10 additional times during a 28 day washout period. Participants underwent venipuncture to assess serum betaine and several other parameters before (PRE) and periodically throughout the washout timeframe (POST0, -4, -7, -10, -13, -16, -19, -22, -25 and -28). All analyses were performed at a significance level of p < 0.05. While analyses failed to detect any differences in any other serum biomarker (p > 0.05), serum betaine was significantly elevated from PRE-to-POST0 (p = 0.047; 2.31 ± 1.05 to 11.1 ± 4.91 µg·mL−1) and was statistically indistinguishable from baseline at POST4 (p = 1.00). Nevertheless, visual data assessment and an inability to assess skeletal muscle concentrations would otherwise suggest that a more conservative 7 day washout period is sufficient to truly return both serum-and-skeletal muscle betaine content to pre-supplementation levels.
Asunto(s)
Betaína , Suplementos Dietéticos , Biomarcadores , Humanos , Masculino , Músculo Esquelético , Proyectos PilotoRESUMEN
Cross-training is a high-intensity functional training (HIFT) with multiple workout modalities. Despite the increasing number of studies in HIFT, there is still no validated test to measure its specific performance. It would also be advisable to determine whether selected cross-training workouts can implement a stimulus corresponding to maximize aerobic work. For these reasons, the purpose of our study was to evaluate the repeatability and reliability of Fight Gone Bad (FGB) workout and to assess its relationship with aerobic fitness. Twenty-one cross-training participants (9 females) finished the study protocol which included three two-day measurement sessions separated by 10 days. During each session, participants had their body composition measured, and they performed two exercise tests. The first test was an incremental cycling test to measure aerobic fitness, and the second was a cross-training specific FGB workout performed the next day. Reliability and repeatability were calculated from the three measurements. The total FGB Score (FGBTOTAL) showed excellent reliability (ICC 0.9, SEM 6%). Moreover, FGBTOTAL was strongly correlated with aerobic fitness (i.e., time to exhaustion (Texh, R2 = 0.72), maximal workload (Wmax, R2 = 0.69), time to gas exchange threshold (TGET, R2 = 0.68), and peak oxygen uptake (VO2peak, R2 = 0.59). We also found that agreement between standardized FGB and standardized aerobic performance indices such as Texh, VO2peak, Wmax, maximum heart rate, TGET, and workload at gas exchange threshold was high by the Bland-Altman method. In conclusion, FGB is a reliable test that can be used in order to measure changes in cross-training performance caused by an intervention. Moreover, FGB is strongly correlated to aerobic fitness.
RESUMEN
Betaine is used to lower elevated plasma homocysteine levels, which are a risk factor for cardiovascular diseases (CVD). However, some studies have shown that betaine may have a negative effect on blood lipids. Betaine supplementation is becoming more and more common, but the relationship between betaine supplementation and blood lipoprotein levels are unclear. The purpose of the study described here was thus to perform a meta-analysis of randomized placebo-controlled trials on the effects of betaine supplementation at a daily dose of at least 4 g on blood lipids in adults. Six randomized controlled trials published between 2002 and 2018 were identified. All six studies used adult participants supplemented with at least 4 g/d of betaine for six to twenty-four weeks. A meta-analysis was carried out using a random-effects model, and the overall effect size was calculated for changes in plasma total cholesterol (TC), HDL cholesterol, LDL cholesterol, and triglycerides (TG). The pooled estimate of the effects of betaine supplementation compared to placebo on TC was 0.34 mmol/L (95% CI: 0.02, 0.65), p = 0.0352. No significant effect was observed for LDL, HDL, or TG. Supplementation with at least 4 g/d of betaine for a minimum of six weeks may moderately increase plasma TC, which might be important in the context of cardiovascular health.
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Betaína , Colesterol/sangre , Suplementos Dietéticos , Hiperhomocisteinemia/tratamiento farmacológico , Adulto , Betaína/efectos adversos , Betaína/uso terapéutico , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Suplementos Dietéticos/efectos adversos , Humanos , Hiperhomocisteinemia/sangre , Ensayos Clínicos Controlados Aleatorios como Asunto , Triglicéridos/sangreRESUMEN
The aim of this study was to assess the effects of probiotic and synbiotic supplementation on glucose metabolism in pregnant women using data from randomized controlled trials. Furthermore, this meta-analysis examines whether the observed effects depend on the presence or absence of gestational diabetes mellitus (GDM), and if the effect is dependent on the type of supplement used (probiotic or synbiotic). We performed a literature search of databases (Medline, Scopus, Web of Knowledge, and Cochrane Library) and identified all relevant randomized controlled trials (RCTs) published prior to May 2019. We compared the effects of probiotic supplementation with the administration of placebos in pregnant women with and without GDM. The systematic review and meta-analysis protocol were registered in the International Prospective Register of Systematic Reviews as number CRD 42019111467. 1119 study participants from 15 selected studies were included. The participants in four studies did not have GDM (being recruited to the study before week 20 of pregnancy) and the participants in the rest of the studies were diagnosed with GDM between weeks 24 and 28 of gestation. The meta-analysis showed that supplementation lowers serum glucose, insulin levels, and HOMA-IR index, but only in pregnant women with GDM. Moreover, both probiotics and synbiotics lower serum insulin level and HOMA-IR index, but the glucose lowering effect is specific only to probiotics and not synbiotics. Probiotic supplementation may improve glucose metabolism in pregnant women with GDM. There is a need for more RCT studies with larger groups to better estimate this effect.
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Diabetes Gestacional/dietoterapia , Suplementos Dietéticos/microbiología , Glucosa/metabolismo , Embarazo/metabolismo , Probióticos/uso terapéutico , Diabetes Gestacional/metabolismo , Femenino , Humanos , Insulina/sangre , Resistencia a la Insulina , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
The aim of this study was the assessment of progressive low-dose sodium bicarbonate (NaHCO3) supplementation on the anaerobic indices in two bouts of Wingate tests (WT) separated by wrestling-specific performance test and assessing the gender differences in response. Fifty-one (18 F) wrestlers completed a randomized trial of either a NaHCO3 (up to 100 mg·kg-1) or a placebo for 10 days. Before and after treatment, athletes completed an exercise protocol that comprised, in sequence, the first WT1, dummy throw test (DT), and second WT2. The number of completed throws increased significantly in males from 19.3 ± 2.6 NaHCO3pre to 21.7 ± 2.9 NaHCO3post. ΔWT2-WT1 improved particularly in the midsection of 30-s WT on NaHCO3. However, no significant differences were found in peak power (PP), power drop (PD) and average power (AP) (analyzed separately for each WT), and ΔWT2-WT1 in PP and PD. Interaction with gender was significant for AP, PP and PD, every second of WT1 and WT2, as well as DT test. In conclusion, our study suggests that the response to NaHCO3 may be gender-specific and progressive low-dose NaHCO3 supplementation allows the advantageous strengthening of wrestling-specific performance in males. It can also lead to maintenance of high anaerobic power mainly in the midsection of the 30-s Wingate test.
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Umbral Anaerobio/efectos de los fármacos , Rendimiento Atlético/fisiología , Suplementos Dietéticos , Bicarbonato de Sodio/administración & dosificación , Lucha/fisiología , Adolescente , Umbral Anaerobio/fisiología , Atletas , Prueba de Esfuerzo/efectos de los fármacos , Femenino , Humanos , Masculino , Factores Sexuales , Adulto JovenRESUMEN
Gastrointestinal side effects are the main problem with sodium bicarbonate (SB) use in sports. Therefore, our study assessed the effect of a new SB loading regimen on anaerobic capacity and wrestling performance. Fifty-eight wrestlers were randomized to either a progressive-dose regimen of up to 100 mgâkg-1 of SB or a placebo for 10 days. Before and after treatment, athletes completed an exercise protocol that comprised, in sequence, the first Wingate, dummy throw, and second Wingate tests. Blood samples were taken pre- and post-exercise. No gastrointestinal side effects were reported during the study. After SB treatment, there were no significant improvements in the outcomes of the Wingate and dummy throw tests. The only index that significantly improved with SB, compared to the placebo (p = 0.0142), was the time-to-peak power in the second Wingate test, which decreased from 3.44 ± 1.98 to 2.35 ± 1.17 s. There were also no differences in blood lactate or glucose concentrations. In conclusion, although the new loading regimen eliminated gastrointestinal symptoms, the doses could have been too small to elicit additional improvements in anaerobic power and wrestling performance. However, shortening the time-to-peak power during fatigue may be particularly valuable and is one of the variables contributing to the final success of a combat sports athlete.
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Rendimiento Atlético , Suplementos Dietéticos , Tolerancia al Ejercicio , Sustancias para Mejorar el Rendimiento/administración & dosificación , Bicarbonato de Sodio/administración & dosificación , Fenómenos Fisiológicos en la Nutrición Deportiva , Lucha , Adolescente , Adulto , Umbral Anaerobio , Atletas , Glucemia/análisis , Diarrea/etiología , Diarrea/prevención & control , Suplementos Dietéticos/efectos adversos , Método Doble Ciego , Femenino , Humanos , Ácido Láctico/sangre , Masculino , Náusea/etiología , Náusea/prevención & control , Sustancias para Mejorar el Rendimiento/efectos adversos , Polonia , Reproducibilidad de los Resultados , Bicarbonato de Sodio/efectos adversos , Adulto JovenRESUMEN
BACKGROUND: Sodium bicarbonate (SB) has been proposed as an ergogenic aid, as it improves high-intensity and resistance exercise performance. However, no studies have yet investigated SB application in CrossFit. This study examined the effects of chronic, progressive-dose SB ingestion on CrossFit-like performance and aerobic capacity. METHODS: In a randomized, double-blind, cross-over trial, 21 CrossFit-trained participants were randomly allocated to 2 groups and underwent 2 trials separated by a 14-day washout period. Participants ingested either up to 150 mgâkg-1 of SB in a progressive-dose regimen or placebo for 10 days. Before and after each trial, Fight Gone Bad (FGB) and incremental cycling (ICT) tests were performed. In order to examine biochemical responses, blood samples were obtained prior to and 3 min after completing each exercise test. RESULTS: No gastrointestinal (GI) side effects were reported during the entire protocol. The overall FGB performance improved under SB by ~6.1% (p<0.001) and it was ~3.1% higher compared to post placebo (PLApost) (p = 0.040). The number of repetitions completed in each round also improved under SB (mean from baseline: +5.8% to +6.4%). Moreover, in ICT, the time to ventilatory threshold (VT) (~8:25 min SBpost vs. ~8:00 min PLApost, p = 0.020), workload at VT (~218 W SBpost vs. ~208 W PLApost, p = 0.037) and heart rate at VT (~165 bpm SBpost vs. ~161 bpm PLApost, p = 0.030) showed higher SBpost than PLApost. Furthermore, the maximum carbon dioxide production increased under SB by ~4.8% (from ~3604 mLâmin-1 to ~3776 mLâmin-1, p = 0.049). Pyruvate concentration and creatine kinase activity before ICT showed higher SBpost than PLApost (~0.32 mmolâL-1 vs. ~0.26 mmolâL-1, p = 0.001; ~275 UâL-1 vs. ~250 UâL-1, p = 0.010, respectively). However, the small sample size limits the wide-application of our results. CONCLUSIONS: Progressive-dose SB ingestion regimen eliminated GI side effects and improved CrossFit-like performance, as well as delayed ventilatory threshold occurrence.
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Rendimiento Atlético , Tracto Gastrointestinal/efectos de los fármacos , Ventilación Pulmonar/efectos de los fármacos , Bicarbonato de Sodio/farmacología , Adulto , Antropometría , Estudios Cruzados , Método Doble Ciego , Ejercicio Físico/fisiología , Prueba de Esfuerzo , HumanosRESUMEN
The glycemic index (GI) of ingested carbohydrates may influence substrate oxidation during exercise and athletic performance. Therefore, the aim of this study was to assess the effect of low- and moderate-GI three-week diets on aerobic capacity and endurance performance in runners. We conducted a randomized crossover feeding study of matched diets differing only in GI (low vs. moderate) in 21 endurance-trained runners. Each participant consumed both, low- (LGI) and moderate-GI (MGI) high-carbohydrate (~60%) and nutrient-balanced diets for three weeks each. At the beginning and end of each diet, participants had their aerobic capacity and body composition measured and performed a 12-min running test. After LGI, time to exhaustion during incremental cycling test (ICT) and distance covered in the 12-min run were significantly increased. The MGI diet led to an increase in maximal oxygen uptake ( V Ë O2max), but no performance benefits were found after the MGI diet. The LGI and MGI diets improved time and workload at gas exchange threshold (GET) during ICT. The results indicate that a three-week high-carbohydrate LGI diet resulted in a small but significant improvement in athletic performance in endurance runners. Observed increase in V Ë O2max on MGI diet did not affect performance.
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Carbohidratos de la Dieta/administración & dosificación , Índice Glucémico , Carga Glucémica , Acondicionamiento Físico Humano/métodos , Carrera , Composición Corporal , Estudios Cruzados , Carbohidratos de la Dieta/efectos adversos , Carbohidratos de la Dieta/metabolismo , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Consumo de Oxígeno , Acondicionamiento Físico Humano/efectos adversos , Resistencia Física , Polonia , Factores de TiempoRESUMEN
The study was aimed at assessing the influence of 3-week low glycemic index (LGI) versus moderate glycemic index (MGI) diet on substrate oxidation during incremental exercise. 17 runners completed two 3-week trials of either LGI or MGI diet in a randomised counterbalanced manner. Before and after each trial the incremental cycling test was performed. Metabolic alternations were observed only within tested diets and no significant differences in fat and carbohydrate (CHO) oxidation were found between MGI and LGI diets. Following MGI diet CHO oxidation rate increased. The AUC of fat oxidation decreased after both diets. Percent contribution of fat to energy yield declined, whereas contribution of CHO was augmented following MGI diet. This study indicates that the 3-week MGI diet increased the rate of carbohydrate oxidation during incremental cycling test and improved performance in acute intense exercise test, while both high-carbohydrate diets downregulated fat oxidation rate.