Caffeine, but Not Creatine, Improves Anaerobic Power Without Altering Anaerobic Capacity in Healthy Men During a Wingate Anaerobic Test.

There is a lack of evidence on the additional benefits of combining caffeine (CAF) and creatine (CRE) supplementation on anaerobic power and capacity. Thus, the aim of the present study was to test the effects of combined and isolated supplementation of CAF and CRE on anaerobic power and capacity. Twenty-four healthy men performed a baseline Wingate anaerobic test and were then allocated into a CRE (n = 12) or placebo (PLA; n = 12) group. The CRE group ingested 20 g/day of CRE for 8 days, while the PLA group ingested 20 g/day of maltodextrin for the same period. On the sixth and eighth days of the loading period, both groups performed a Wingate anaerobic test 1 hr after either CAF (5 mg/kg of body mass; CRE + CAF and PLA + CAF conditions) or PLA (5 mg/kg of body mass of cellulose; CRE + PLA and PLA + PLA conditions) ingestion. After the loading period, changes in body mass were greater (p < .05) in the CRE (+0.87 ± 0.23 kg) than in the PLA group (+0.13 ± 0.27 kg). In both groups, peak power was higher (p = .01) in the CAF (1,033.4 ± 209.3 W) than in the PLA trial (1,003.3 ± 204.4 W), but mean power was not different between PLA and CAF trials (p > .05). In conclusion, CAF, but not CRE ingestion, increases anaerobic power. Conversely, neither CRE nor CAF has an effect on anaerobic capacity.

Caffeine Mouth Rinse Plus Ingestion Improves the 10-Km Time Trial Compared to Caffeine Mouth Rinse Alone.

Background: The benefits of caffeine to physical performance have been extensively demonstrated, however, it has recently been speculated that there is an effect of the administration route on its effectiveness. Purpose: The current study investigated the effect of caffeine mouth rinse in isolation or combined with ingestion on performance in a 30-minute constant-load exercise followed by a 10-km cycling time trial. Methods: Ten physically active men performed a 30-minute constant-load exercise at 50% of the graded test Wmax, followed by a 10-km cycling time trial. Before and at the middle points of the constant-load exercise and 10-km cycling time trial, the following conditions were administered: PLA (cellulose ingestion plus mouth rinsing with magnesium sulfate), ING (5 mg.kg-1 of caffeine ingestion plus mouth rinsing with magnesium sulfate), MR (cellulose ingestion plus mouth rinsing with 1.2% caffeine), and COMB (5 mg.kg-1 of caffeine ingestion plus mouth rinsing with 1.2% caffeine). Results: During the 30-minute constant-load exercise, COMB presented a lower rating of perceived exertion (RPE) than MR (p = .04). For the 10-km time trial, the COMB was faster than MR (MR = 1363 ± 345 vs. COMB = 1291 ± 308s, Δ% = 5.57, p = .05). Mean power output was higher in COMB than PLA, ING, and MR (234 ± 15 vs. 169 ± 29, 148 ± 11, and 145 ± 12 W, respectively). There were no differences between conditions for heart rate and RPE during the 10-km time trial. Conclusion: In summary, caffeine mouth rinsing potentiated the effects of caffeine ingestion during the 10-km time trial compared to caffeine mouth rinsing alone.

Ultra-processed food consumption and metabolic syndrome: a cross-sectional study in Quilombola communities of Alagoas, Brazil.

BACKGROUND: The processing of food can cause changes that turn them into risk factors for chronic diseases. A higher degree of food processing is associated with the development of chronic non-communicable diseases (NCDs), including the metabolic syndrome (MetS). The objective of this study was to analyze the relationship between ultra-processed food (UPF) consumption and the prevalence of MetS and its risk factors, focusing on a population group especially subjected to precarious living conditions and food insecurity. METHOD: Cross-sectional population-based study with women (19 to 59 years) from Quilombola communities of Alagoas. The socioeconomic, demographic, anthropometric, health status, lifestyle, and food intake (24-h recall) variables were analyzed. The dependent variable was the MetS, defined using the harmonization criteria of the Joint Interim Statement, and its components. The foods consumed were categorized according to the Nova Classification, assuming the highest UPF consumption as risk exposure. The measure of association was the prevalence ratio (PR) and respective 95%CI, calculated by Poisson regression with robust variance. We also analyzed the association with the Nova score of UPF consumption. RESULTS: We investigated 895 women (38.9 ± 11.0 years), of whom 48.3% had MetS. On average, 15.9% of the total energy intake came from UPF. Lower Nova scores were associated with a lower prevalence of diabetes and low HDL. Higher UPF consumption was associated with a 30% higher prevalence of hypertension (PR = 1.30; 95%CI: 1.06-1.61). CONCLUSION: The highest UPF consumption was positively associated with the prevalence of hypertension, while a lower Nova score was a protective factor against diabetes and low HDL. UPF consumption in Quilombola communities is important but lower than that observed in the Brazilian population in general. It is suggested that public health programs be implemented to promote healthy eating while valuing the existing eating habits and traditions among the remaining Brazilian Quilombola people.

RESUMO: INTRODUçãO: O processamento de alimentos pode causar alterações que os transformam em fatores de risco para doenças crônicas. Um maior grau de processamento de alimentos está associado ao desenvolvimento de doenças crônicas não transmissíveis (DCNT), incluindo a síndrome metabólica (SM). O objetivo deste estudo foi analisar a relação entre o consumo de alimentos ultraprocessados (AUP) e a prevalência de SM e seus fatores de risco, com foco em um grupo populacional especialmente submetido a precárias condições de vida e insegurança alimentar. MéTODO: Estudo transversal de base populacional com mulheres (19 a 59 anos) de comunidades Quilombolas de Alagoas. Foram analisadas as variáveis socioeconômicas, demográficas, antropométricas, estado de saúde, estilo de vida e ingestão alimentar (recordatório de 24 horas). A variável dependente foi a SM, definida a partir dos critérios de harmonização do Joint Interim Statement, e seus componentes. Os alimentos consumidos foram categorizados de acordo com a Classificação Nova, assumindo como exposição de risco o maior consumo de AUP. A medida de associação foi a razão de prevalência (RP) e respectivo IC 95%, calculado por regressão de Poisson com variância robusta. Também analisou-se a associação com o Escore Nova de consumo de AUP. RESULTADOS: Foram investigadas 895 mulheres (38,9 ± 11,0 anos), das quais 48,3% tinham SM. Em média, 15,9% da ingestão total de energia provinham de AUP. Escores Nova mais baixos foram associados a uma menor prevalência de diabetes e HDL baixo. O maior consumo de AUP se associou a uma prevalência 30% maior de hipertensão arterial (RP = 1,30; IC95%: 1,06-1,61). CONCLUSãO: O maior consumo de AUP se associou positivamente à prevalência de hipertensão, enquanto o menor escore Nova foi fator de proteção contra diabetes e baixo HDL. O consumo de AUP nas comunidades Quilombolas é relevante, mas inferior ao observado na população brasileira em geral. Sugere-se a implementação de programas de saúde pública que promovam a alimentação saudável, valorizando os hábitos e tradições alimentares existentes entre os remanescentes Quilombolas brasileiros.

Effects of creatine and caffeine ingestion in combination on exercise performance: A systematic review.

Creatine (CRE) and caffeine (CAF) have been used as ergogenic aids to improve exercise performance. The present study reviewed the current evidence supporting the additional use of CAF intake during or after the CRE loading on exercise performance. The search was carried out in eight databases, with the methodological quality of the studies assessed via the QualSyst tool. From ten studies that met the criteria for inclusion, six had strong, three moderate, and one weak methodological quality. CAF was ingested ∼1 h before the performance trial (5-7 mg.kg-1) after a CRE loading period (5-6 days with 0.3 g.kg-1.d-1) in five studies, with the combination CAF + CRE providing additional ergogenic effect compared to CRE alone in three of these studies. Furthermore, CAF was ingested daily during the CRE loading protocol in five studies, with CAF showing additive benefits compared to CRE alone only in one study (3 g.d-1 of CRE during 3 days + 6 mg.kg-1 of CAF for 3 days). The combination CAF + CRE seems to provide additional benefits to exercise performance when CAF is acutely ingested after a CRE loading. There is, however, no apparent benefit in ingesting CAF during a CRE loading period.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2021.2007470.

Effect of carbohydrate mouth rinse on muscle strength and muscular endurance: A systematic review with meta-analysis.

The present systematic review with meta-analysis summarized studies that investigated the effect of carbohydrate (CHO) mouth rinse on muscle strength and muscular endurance. The search was performed in six databases. Thirteen randomized clinical trials were selected and the standardized mean difference between CHO mouth rinse and placebo for maximal strength and muscular endurance was determined via a random-effects model using Review Manager 5.4 software. Meta-regression was also performed to explore the influence of load, number of sets, number of exercises, fasting time, CHO concentration, and number of mouth rinses on the main outcomes. There was no significant effect of CHO mouth rinse on maximal strength (mean difference= 0.25 kg, 95%CI - 1.81 to 2.32 kg, z = 0.24, p = 0.810). However, there was a significant positive effect of CHO mouth rinse on muscular endurance (mean difference = 1.24 repetitions, 95%CI 0.70 to 1.77 repetitions, z = 4.55, p < 0.001). Meta-regression identified that CHO mouth rinse has greater benefits on muscular endurance when using high workloads, multiple exercises, and a smaller number of mouth rinses (p = 0.001). In conclusion, CHO mouth rinse has no effect on maximal muscle strength but has a positive effect on muscular endurance and seems to optimize when fewer mouth rinses, high workloads and numbers of exercises are used.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2022.2057417.

Effects of caffeine ingestion on cardiopulmonary responses during a maximal graded exercise test: a systematic review with meta-analysis and meta-regression.

While the effects of caffeine ingestion on endurance performance are well known, its effects on cardiopulmonary responses during a maximal graded exercise test have been less explored. This study systematically reviewed and meta-analyzed studies investigating the effects of caffeine ingestion on cardiopulmonary responses during a maximal graded exercise test. A search was performed in four databases, and study quality was assessed using the PEDro scale. Data reported by the selected studies were pooled using random-effects meta-analysis, with selected moderator effects assessed via meta-regression. Twenty-one studies with good and excellent methodological quality were included in this review. Compared to placebo, caffeine increased peak minute ventilation (SMD = 0.33; p = 0.01) and time to exhaustion (SMD = 0.41; p = 0.01). However, meta-regression showed no moderating effects of dosage and timing of caffeine ingestion, stage length, or total length of GXT (all p > 0.05). Caffeine ingestion did not affect peak oxygen uptake (SMD = 0.13; p = 0.42), peak heart rate (SMD = 0.27; p = 0.07), peak blood lactate concentration (SMD = 0.60; p = 0.09), peak tidal volume (SMD = 0.10; p = 0.69), peak breathing frequency (SMD =0.20; p = 0.23), or peak power output (SMD = 0.22; p = 0.28). The results of this systematic review with meta-analysis suggest that caffeine increases time to exhaustion and peak minute ventilation among the cardiopulmonary variables assessed during GXT.

The rating of perceived exertion is able to differentiate the post-matches metabolomic profile of elite U-20 soccer players.

PURPOSE: The study aimed to assess the metabolic impact of elite Brazilian U-20 players using the rating of perceived exertion scale (RPE) to discriminate metabolomics sensitivity post-two soccer games separated by a short recovery interval. METHODS: Urine was collected immediately and then 20 h after two soccer matches of elite Brazilian U-20 players. RPE was collected after games. The spectra were pre-processed using TopSpin®3.2 software. Chenomx®software was used to identify metabolites in the urine through the available database. RESULTS: The results showed that the metabolic pathways related to energy production, cellular damage, and organic stresses were changed immediately after the game. 20 h after the games, antioxidant and anti-inflammatory pathways related to cell recovery were identified (e.g., gallic acid, ascorbate, and betaine). The matrix of positive correlations between metabolites was more predominant and stronger after game 2 than game 1. T-distribution registered metabolites discriminated below and above 7 on the RPE scale. Athletes with higher RPE values showed a high metabolite profile related to muscle damage (e.g., creatine, creatinine, and glycine) and energy production (e.g., creatine, formate, pyruvate, 1,3 dihydroxyacetone) 20 h post-soccer match. There was a different metabolic profile between athletes with higher and lower RPE values. CONCLUSION: Metabolomics analysis made it possible to observe the metabolic impacts of energy production and muscular damage. RPE identified internal load changes within the group as a result of match intensity in soccer. The correlation matrix indicated a greater predominance of positive and strong correlations between metabolites in the second game compared to the first game.

Airflow restriction mask induces greater central fatigue after a non-exhaustive high-intensity interval exercise.

The airflow restriction mask (ARM) is a practical and inexpensive device for respiratory muscle training. Wearing an ARM has recently been combined with high-intensity interval exercise (HIIE), but its effect on neuromuscular fatigue is unknown. The present study investigated the effects of ARM wearing on neuromuscular fatigue after an HIIE session. Fourteen healthy men performed two HIIE sessions (4 × 4 min at 90% HRmax , 3 min recovery at 70% HRmax ) with or without an ARM. Neuromuscular fatigue was quantified via pre- to post-HIIE changes in maximal voluntary contraction (MVC), voluntary activation (VA, central fatigue), and potentialized evoked twitch force at 100, 10, and 1 Hz (peripheral fatigue). Blood pH and lactate were measured before and after the HIIE session, while HR, SpO2 , dyspnea, physical sensation of effort (P-RPE), and Task Effort and Awareness (TEA) were recorded every bout. The exercise-induced decrease in MVC was higher (p < 0.05) in the ARM (-28 ± 12%) than in the Control condition (-20 ± 11%). The VA decreased (p < 0.05) in the ARM (-11 ± 11%) but not in the control condition (-4 ± 5%, p > 0.05). Pre- to post-HIIE declines in evoked twitch at 100, 10, and 1 Hz were similar (p > 0.05) between ARM and control conditions (ARM: -18 ± 10, -43 ± 11 and -38 ± 12%; Control: -18 ± 14, -43 ± 12 and -37 ± 17%). When compared with the control, the HIIE bout wearing ARM was marked by higher heart rate, plasma lactate concentration, dyspnea, P-RPE and TEA, as well as lower SpO2 and blood pH. In conclusion, ARM increases perceptual and physiological stress during a HIIE, which may lead to a greater post-exercise central fatigue.

Validation and reproducibility of a FFQ focused on pregnant women living in Northeastern Brazil.

OBJECTIVE: The aim of the current study is to assess the validity and reproducibility of a FFQ focused on pregnant women living in Northeastern Brazil. DESIGN: Three 24-hour-dietary recalls (24 hR) and two FFQ were applied at 15-d intervals between research stages in order to confirm the validity and reproducibility of the FFQ. Validity assessment was based on Pearson's correlation coefficient (PCC) or Spearman's correlation coefficient (SCC) between FFQ and the mean of three 24 hR (the 24 hR was used as reference standard), whereas reproducibility assessment was based on the intraclass correlation coefficient (ICC) among FFQ, and P < 0·05 was set as significance level. SETTING: Public health network of a capital city in Northeastern Brazil. PARTICIPANTS: Overall, 100 pregnant women were included in the study. RESULTS: The PCC or SCC adopted in the validity analysis recorded the recommended values (from 0·4 and 0·7) for energy (0·44; P < 0·001), carbohydrate (0·40; P < 0·001), vitamins B2 (0·40; P < 0·001), B5 (0·40; P < 0·001), E (0·47; P < 0·001), B12 (0·48; P < 0·001), phosphorus (0·92; P < 0·001), Mg (0·81; P < 0·001), Se (0·70; P < 0·001), cholesterol (0·64; P < 0·001), saturated (0·76; P < 0·001), polyunsaturated (0·73; P < 0·001) and monounsaturated fats (0·87; P < 0·001) and fibres (0·77; P < 0·001). Mg (0·72; P < 0·001), Fe (0·65; P < 0·001), lipid (0·56; P < 0·001) and energy (0·55; P < 0·001) presented ICC within the recommended reproducibility values. CONCLUSIONS: The FFQ developed in the current study is a useful tool to assess the usual food intake of pregnant women.

Elaboração, validação e reprodutibilidade de um questionário de frequência alimentar para hipertensos e/ou diabéticos / Development, validation and reproducibility of a food frequency questionnaire focused on adult hypertensive and/or diabetic individuals

Objetivo: O presente estudo teve por objetivo elaborar e avaliar a validade e a reprodutibilidade de um questionário de frequência alimentar (QFA) para hipertensos e/ou diabéticos do município de Maceió-AL, Brasil. Métodos: O QFA foi elaborado a partir de 1.603 inquéritos dietéticos recordatórios de 24 h (IDR24H). Para avaliar a validade e a reprodutibilidade do QFA aplicaram-se, em uma amostra de 40 indivíduos, três QFAS e três IDR24H concomitantemente e com intervalo máximo de 45 dias entre as aplicações. A validade foi avaliada por meio dos coeficientes de correlação de Pearson (CCP) ou de Spearman (CCS) entre o QFA 1, 2 e 3, e a média dos 3IDR24H, adotando-se o IDR24H como padrão de referência; e a reprodutibilidade, por meio do coeficiente de correlação intraclasse (CCI) entre os QFAs. Resultados: Quanto à validade, os CCP ou CCS atingiram os valores recomendados entre 0,4 e 0,7 para energia, macronutrientes, cálcio e sódio para as aplicações 1 e 2 do QFA (validade satisfatória); e para os demais nutrientes, CCP < 0,4. Quanto à reprodutibilidade, todos os nutrientes estudados apresentaram CCI dentro dos valores recomendados, exceto potássio entre QFA1 e QFA3 (CCI = 0,28). Conclusão: O QFA elaborado e avaliado neste estudo constitui um bom instrumento de avaliação de consumo alimentar para avaliação de energia, macronutrientes, cálcio e sódio para hipertensos e/ou diabéticos, podendo fornecer informações importantes para estudos de epidemiologia nutricional neste público-alvo. (AU)

Objective: The aims of the current study are to develop and assess the validity and reproducibility of a food frequency questionnaire (FFQ) focused on hypertensive and/or diabetic individuals living in Maceió City - AL, Brazil. Methods: The questionnaire was developed based on 1,603 twenty-four-hour recall dietary surveys (24-HDR). Three FFQs and three 24-HDRs were concomitantly applied to a sample of 40 individuals, at maximum interval of 45 days between applications, in order to assess FFQ validity and reproducibility. Validity assessment was based on Pearson's (PCC) or Spearman's (SCC) correlation coefficient between FFQs 1, 2, 3 and the mean of three 24-HDRs (the 24- HDR was used as reference standard). Reproducibility assessment was based on the intraclass correlation coefficient (ICC) among FFQs. Results: PCCs or SCCs recorded the recommended validity values (from 0.4 and 0.7) for energy, macronutrients, calcium and sodium in FFQs 1 and 2 (satisfactory validity), whereas other nutrients recorded PCC < 0.4. All investigated nutrients presented ICC within the recommended reproducibility values, except for potassium, which recorded ICC equal to 0.28 between FFQs 1 and 3. Conclusion: The FFQ developed and evaluated in the current study is a good food intake-evaluation instrument to assess energy, macronutrients, calcium and sodium in hypertensive and/or diabetic individuals, since it can provide important information for studies about nutritional epidemiology in this target population. (AU)

Twice-a-day training improves mitochondrial efficiency, but not mitochondrial biogenesis, compared with once-daily training.

Exercise training performed with lowered muscle glycogen stores can amplify adaptations related to oxidative metabolism, but it is not known if this is affected by the "train-low" strategy used (i.e., once-daily versus twice-a-day training). Fifteen healthy men performed 3 wk of an endurance exercise (100-min) followed by a high-intensity interval exercise 2 (twice-a-day group, n = 8) or 14 h (once-daily group, n = 7) later; therefore, the second training session always started with low muscle glycogen in both groups. Mitochondrial efficiency (state 4 respiration) was improved only for the twice-a-day group (group × training interaction, P < 0.05). However, muscle citrate synthase activity, mitochondria, and lipid area in intermyofibrillar and subsarcolemmal regions, and PGC1α, PPARα, and electron transport chain relative protein abundance were not altered with training in either group (P > 0.05). Markers of aerobic fitness (e.g., peak oxygen uptake) were increased, and plasma lactate, O2 cost, and rating of perceived exertion during a 100-min exercise task were reduced in both groups, although the reduction in rating of perceived exertion was larger in the twice-a-day group (group × time × training interaction, P < 0.05). These findings suggest similar training adaptations with both training low approaches; however, improvements in mitochondrial efficiency and perceived effort seem to be more pronounced with twice-a-day training.NEW & NOTEWORTHY We assessed, for the first time, the differences between two "train-low" strategies (once-daily and twice-a-day) in terms of training-induced molecular, functional, and morphological adaptations. We found that both strategies had similar molecular and morphological adaptations; however, only the twice-a-day strategy increased mitochondrial efficiency and had a superior reduction in the rating of perceived exertion during a constant-load exercise compared with once-daily training. Our findings provide novel insights into skeletal muscle adaptations using the "train-low" strategy.

Cycling time trial performance is improved by carbohydrate ingestion during exercise regardless of a fed or fasted state.

PURPOSE: We tested the hypothesis that carbohydrate ingestion during exercise improves time trial (TT) performance and that this carbohydrate-induced improvement is greater when carbohydrates are ingested during exercise in a fasted rather than a fed state. METHODS: Nine males performed 105 minutes of constant-load exercise (50% of the difference between the first and second lactate thresholds), followed by a 10-km cycling TT. Exercise started at 9 am, 3 hours after either breakfast (FED, 824 kcal, 67% carbohydrate) or a 15-hour overnight fast (FAST). Before exercise, after every 15 minutes of exercise and at 5 km of the TT, participants ingested 2 mL kg-1 body mass of a non-caloric sweetened solution containing either carbohydrate (8% of maltodextrin, CHO) or placebo (0% carbohydrate, PLA). RESULTS: Irrespective of the fasting state, when carbohydrate was ingested during exercise, the rating of perceived exertion (RPE) was lower throughout the constant-load exercise, while the plasma glucose concentration and carbohydrate oxidation were higher during the last stages of the constant-load exercise (P < 0.05). Consequently, TT performance was faster when carbohydrate was ingested during exercise (18.5 ± 0.3 and 18.7 ± 0.4 minutes for the FEDCHO and FASTCHO conditions, respectively) than when the placebo was ingested during exercise (20.2 ± 0.8 and 21.7 ± 1.4 minutes for the FEDPLA and FASTPLA conditions, respectively), regardless of fasting. CONCLUSION: These findings indicate that even when breakfast is provided before exercise, carbohydrate ingestion during exercise is still beneficial for exercise performance. However, ingesting carbohydrate during exercise can overcome a lack of breakfast.

Effect of acute nitrate ingestion on V̇O2 response at different exercise intensity domains.

While nitrate supplementation influences oxygen uptake (V̇O2) response to exercise, this effect may be intensity dependent. The purpose of this study was to investigate the effect of acute nitrate supplementation on V̇O2 response during different exercise intensity domains in humans. Eleven men ingested 10 mg·kg-1 body mass (8.76 ± 1.35 mmol) of sodium nitrate or sodium chloride (placebo) 2.5 h before cycling at moderate (90% of gas exchange threshold; GET), heavy (GET + 40% of the difference between GET and peak oxygen uptake (V̇O2peak), Δ 40) or severe (GET + 80% of the difference between GET and V̇O2peak, Δ 80) exercise intensities. Volunteers performed exercise for 10 min (moderate), 15 min (heavy) or until exhaustion (severe). Acute nitrate supplementation had no effect on any V̇O2 response parameters during moderate and severe exercise intensities. However, the V̇O2 slow amplitude (nitrate: 0.93 ± 0.36 L·min-1 vs. placebo: 1.13 ± 0.59 L·min-1, p = 0.04) and V̇O2 slow gain (nitrate: 5.81 ± 2.37 mL·min-1·W-1 vs. placebo: 7.09 ± 3.67 mL·min-1·W-1, p = 0.04) were significantly lower in nitrate than in placebo during the heavy exercise intensity. There was no effect of nitrate on plasma lactate during any exercise intensity (p > 0.05). Time to exhaustion during the severe exercise intensity was also not affected by nitrate (p > 0.05). In conclusion, acute nitrate supplementation reduced the slow component of V̇O2 only when performing heavy-intensity exercise, which might indicate an intensity-dependent effect of nitrate on V̇O2 response.

CHO Mouth Rinse Ameliorates Neuromuscular Response with Lower Endogenous CHO Stores.

PURPOSE: This study aimed to investigate carbohydrate (CHO) mouth rinse response on neuromuscular activity, fuel oxidation rates, and cycling performance with different initial levels of endogenous CHO availability. METHODS: In a double-blind, randomized placebo-controlled design, eight males completed six experimental mouth rinse trials: CHO (6.4% maltodextrin) or placebo solution in a fed state (FED), 12-h fasted state (FAST), or a combined exercise-depleted muscle glycogen and 12-h fasted state (DEP). Trials consisted of 30-min cycling at 90% of gas exchange threshold, followed by a 20-km cycling time trial. Plasma lactate, plasma glucose, oxygen uptake, and EMG activity were measured, and CHO and fat oxidation rates were calculated. RESULTS: CHO mouth rinse maintained higher plasma glucose levels as the constant load exercise progressed (P = 0.023). The reduced EMG activity in the DEP condition with the placebo during constant load exercise was ameliorated with CHO mouth rinse (P < 0.01). Furthermore, the power output and the EMG activity throughout the 20-km time trial were reduced in the DEP condition with placebo but were both restored with CHO mouth rinse (P < 0.05). Time trial performance was only improved with CHO in the DEP compared with the corresponding placebo (P < 0.05), and no differences between supplements were observed in the FED or FAST states. Analyses of the qualitative inference showed "benefit very likely" of CHO mouth rinse on exercise performance in DEP, "possibly benefit" in FAST, and "negligible or trivial" in FED. CHO mouth rinse had no effect on CHO and fat oxidation rates in either exercise mode. CONCLUSION: The CHO mouth rinse influences exercise performance when endogenous CHO availability is low, and an enhanced central motor drive is potentially the main influencing mechanism.