Cholesterol intake and serum total cholesterol levels are not associated with total testosterone levels in men: a cross-sectional study from NHANES 2013-2014.

BACKGROUND: Testosterone (T) is an anabolic hormone crucial to the structure and function of skeletal muscle. Testosterone is partially synthesized from cholesterol, but little is known about the relationship of cholesterol intake and serum cholesterol with T levels. AIM: To investigate whether cholesterol intake and serum total cholesterol (TC) levels are associated with serum total testosterone (TT) levels in men. METHODS: A cross-sectional study enrolling 1996 men aged 20 to 80 years from National Health and Nutrition Examination Survey (NHANES) 2013-2014 was carried out. Diet assessment was performed using two 24-h food recalls, and TT levels were measured by liquid chromatography coupled with tandem mass spectrometry. Regression analyses were performed to evaluate whether TT was associated with cholesterol intake and serum TC levels. RESULTS: Neither cholesterol intake nor serum TC levels were associated with TT levels in unadjusted and adjusted analyses (adjustment for energy, total fat and alcohol intake, smoking, age, physical activity, family income, marital status, race, educational level, diabetes, hypertension, and body mass index). CONCLUSION: Dietary cholesterol intake and TC levels are not associated with TT levels in men from the USA.

Association between serum uric acid and muscle strength in older adults with or without gout diagnosis: NHANES 2011-2014.

BACKGROUND & AIMS: Increased oxidative stress seems to be one of the causes of muscle strength loss during aging. Uric acid (UA) is an important antioxidant that has been positively associated with muscle strength in older adults. However, UA is also a prerequisite for gout, which is a type of arthritis that increases inflammation. The association between UA and muscle strength in individuals with gout is unknown. The aim of the study was to associate muscle strength with UA in older adults with or without gout diagnosis. METHODS: The present study evaluated older adults aged from 60 to 80 years from National Health and Nutrition Examination Survey (NHANES) 2011-2012 and 2013-2014. A total of 2529 individuals (1249 men and 1280 women) were evaluated, with (n = 201) or without (n = 2328) gout diagnosis. Muscle strength was measured using a handgrip dynamometer. The combined grip strength (sum of highest values of both hands) was evaluated. Linear regression analysis was performed to evaluate the association between UA and strength adjusting for confounders. RESULTS: Evaluating the individuals without gout, UA was positively associated with muscle strength [(ß = 0.66 (CI = 0.08; 1.24); p = 0.028)]. However, this association was not significant in individuals with gout [(ß = 0.20 (CI = - 1.18; 1.58); p = 0.774)]. CONCLUSION: Serum UA is positively associated with handgrip strength only in older adults without gout diagnosis. These results suggest that the presence of gout may avoid a positive association between UA and muscle strength in older adults.

C-reactive protein, but not neutrophil-lymphocyte ratio, is inversely associated with muscle strength only in older men: NHANES 1999-2002.

To evaluate the association of inflammation (C-reactive protein (CRP) and neutrophil-lymphocyte ratio (NLR) levels) with muscle strength in older adults. We also aimed to evaluate whether these associations are sex-specific. A cross-sectional study was performed with data from the National Health and Nutrition Examination Survey (NHANES) 1999-2000 and 2001-2002. A total of 2387 individuals over 50 years of both sexes were evaluated, according to the eligibility criteria for the strength test. Muscle strength was measured by Kinetic Communicator isokinetic dynamometer; while the NLR was obtained by the ratio of the total neutrophil for lymphocyte count and CRP was quantified by latex nephelometry. Linear regression analyses, crude and adjusted for confounders, were used to estimate the coefficients and 95 % confidence intervals for peak strength (muscle strength) by tertiles of NLR and CRP. There was no association between NLR and peak strength for both sexes. CRP levels were inversely associated with peak force in men [2nd tertile ß = -3.33 (-15.92; 9.25); 3rd tertile ß = -24.69 (-41.18; -8.20), p for trend = 0.005], but not in women [2nd tertile ß = -3.22 (-15.00; 8.56); 3rd tertile ß = -9.23 (-28.40; -9.94), p for trend = 0.332]. In conclusion, NLR levels were not associated with muscle strength in both sexes. CRP levels were inversely associated with muscle strength in older men, but not in women, suggesting that the association between inflammation and muscle strength in older adults can be sex-specific.

Plasma omega-3 fatty acids are positively associated with appendicular muscle mass index only in adults with low protein intake: Results from NHANES 2011-2012.

BACKGROUND: Omega-3 (ω-3) fatty acids may indirectly increase muscle protein synthesis making the muscle more sensitive to amino acids uptake; therefore, ω-3 could promote benefits on muscle mass mainly when protein intake is low. However, no study has evaluated the association between ω-3 fatty acids and muscle mass according to protein intake. AIM: To evaluate the association between plasma ω-3 fatty acids and appendicular muscle mass index (AMMI) in adults according to the protein intake. METHODS: A cross-sectional study was performed evaluating 1037 individuals aged 20-59 years from a sub-sample of the National Health and Nutrition Examination Survey (NHANES) 2011-2012. Gas chromatography-mass spectrometry method was used to assess plasma ω-3 fatty acids. The lean mass was evaluated by dual-energy x-ray absorptiometry (DXA) and AMMI (kg/m2) was calculated by appendicular lean mass (kg) divided by height squared. The evaluation of protein intake was performed using two 24-h dietary recalls. Linear regression analysis was performed to assess the association of total plasma ω-3, docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), alpha-linolenic acid (ALA), and EPA plus DHA with AMMI according to protein intake (<0.8; ≥0.8; ≥0.8 - <1.2; ≥1.2 - <1.6; and ≥1.6 g/kg/d). RESULTS: Total plasma ω-3 (ß = 0.0030; CI = 0.0013-0.0046; p = 0.002), ALA (ß = 0.0063; CI = 0.0020-0.0107; p = 0.008), EPA (ß = 0.0073; CI = 0.0005-0.0142, p = 0.037), DHA (ß = 0.0057; CI = 0.0022-0.0093; p = 0.004) and EPA + DHA (ß = 0.0040; CI = 0.0010-0.0071; p = 0.013) were positively associated with AMMI in individuals with low protein intake (<0.8 g/kg). However, no association was observed in individuals with protein intake higher than 0.8 g/kg. CONCLUSION: Plasma ω-3 fatty acids were positively associated with AMMI only in individuals with low protein intake.

Effects of probiotic supplementation on performance of resistance and aerobic exercises: a systematic review.

CONTEXT: Strenuous exercise may lead to negative acute physiological effects that can impair athletic performance. Some recent studies suggest that probiotic supplementation can curtail these effects by reducing the permeability of the intestinal barrier, yet results are inconsistent. OBJECTIVE: The aim of this systematic review is to assess the effects of probiotic supplementation on athletic performance. DATA SOURCES: The PubMed/MEDLINE, Cochrane, and Scopus databases were searched for articles that assessed the effects of probiotic supplementation on athletic performance. DATA EXTRACTION THIS SYSTEMATIC REVIEW IS REPORTED ACCORDING TO: PRISMA guidelines. Risk of bias was assessed through the Cochrane RoB 2.0 tool. Seventeen randomized clinical trials assessing athletic performance as the primary outcome were included. In total, 496 individuals (73% male) comprising athletes, recreationally trained individuals, and untrained healthy individuals aged 18 to 40 years were investigated. DATA ANALYSIS: Three studies showed an increase or an attenuation of aerobic performance (decline in time to exhaustion on the treadmill) after supplementation with probiotics, while 3 found an increase in strength. However, most studies (n = 11) showed no effect of probiotic consumption on aerobic performance (n = 9) or muscular strength (n = 2). The most frequently used strain was Lactobacillus acidophilus, used in 2 studies that observed positive results on performance. Studies that used Lactobacillus plantarum TK10 and Lactobacillus plantarum PS128 also demonstrated positive effects on aerobic performance and strength, but they had high risk of bias, which implies low confidence about the actual effect of treatment. CONCLUSION: There is not enough evidence to support the hypothesis that probiotics can improve performance in resistance and aerobic exercises. Further well-controlled studies are warranted.

Serum α-Carotene, but Not Other Antioxidants, Is Positively Associated with Muscle Strength in Older Adults: NHANES 2001-2002.

Aging is associated with an increased reactive oxygen species that can decrease muscle strength. Thus, antioxidant substances could be positively associated with muscle strength in older adults. To investigate the association between serum antioxidants and muscle strength in older adults. A cross-sectional study evaluating 1172 individuals (627 men and 545 women), aged 50 to 85 years from NHANES 2001-2002, was performed. Carotenoids (α-carotene, trans-ß-carotene, cis-ß-carotene, ß-cryptoxanthin, lutein/zeaxanthin combination, trans-lycopene), vitamin E, and retinol were analyzed via the high-performance liquid chromatography method. Muscle strength was evaluated by the isokinetic knee extension test. Linear regression was performed to evaluate the association between tertiles of serum antioxidant levels and strength, adjusted for confounders (energy and protein intake, body mass index, sex, age, C-reactive protein, uric acid, race/ethnicity, marital status, annual household income, educational level, physical activity, smoking, hypertension, arthritis, and diabetes). Alpha-carotene levels (p-trend = 0.027) were positively associated with muscle strength. However, serum vitamin E, trans-ß-carotene, cis-ß-carotene, ß-cryptoxanthin, carotenoids, and retinol levels were not associated with strength. Serum α-carotene, but not other antioxidants, was positively associated with muscle strength in older adults.

Serum uric acid is not associated with appendicular muscle mass index in young and middle-aged adults: Results from NHANES 2011-2012.

BACKGROUND: Recent studies have evaluated the association between uric acid (UA) and muscle mass in older adults; however, little is known about this relationship in young and middle-aged individuals. Our aim was to investigate whether serum UA is associated with appendicular muscle mass index (AMMI) in young and middle-aged individuals. We also aimed to evaluate whether this association is sex-specific. METHODS: A cross-sectional study was performed with young and middle-aged individuals aged from 20 to 59 years from National Health and Nutrition Examination Survey (NHANES) 2011-2012. A total of 2255 individuals (1440 young and 815 middle-aged individuals; 1167 men and 1088 women) were evaluated. Body composition was assessed by Dual Energy X-ray absorptiometry (DXA) and AMMI was calculated using the arms plus legs lean mass divided by the height squared. UA levels were measured by colorimetric method. Regression analyzes were performed to evaluate whether AMMI is associated with the tertiles of UA levels after adjustments for potential confounders. RESULTS: In the unadjusted analyzes, serum UA was positively associated with AMMI for total sample, young, and middle-aged individuals of both sexes. However, after adjustments for confounders, UA levels were no longer associated with AMMI independent of the age-rage and sex. CONCLUSION: Serum UA is not associated with AMMI in young or middle-aged individuals independent of the sex.

Association between Plasma Omega-3 and Handgrip Strength According to Glycohemoglobin Levels in Older Adults: Results from NHANES 2011-2012.

BACKGROUND: Low muscle strength is a predictor of mortality in older adults. Although the evidence concerning hyperglycemia is limited, evidence shows that omega-3 (ω-3) intake may be positively associated with muscle strength. However, the association between plasma ω-3 and muscle strength in older adults according to glycohemoglobin (HbA1c) levels has not yet been investigated. OBJECTIVE: To evaluate whether plasma ω-3 levels are associated with handgrip strength in individuals over 50 years according to HbA1c levels. METHODS: This cross-sectional study included 950 older adults (50-85 years) from NHANES 2011-2012. Linear regression analysis was performed to evaluate the association between plasma ω-3 and handgrip strength in individuals with elevated (≥5.7%) or normal HbA1c levels after adjustments for confounders. RESULTS: Total plasma ω-3, docosahexaenoic acid, eicosapentaenoic acid and alpha-linolenic acid were not associated with handgrip strength in older adults regardless of HbA1c levels. CONCLUSION: Plasma ω-3 levels are not associated with handgrip strength in individuals over 50 years old independent of HbA1c levels.

Redox Status of Postmenopausal Women with Single or Multiple Cardiometabolic Diseases Has a Similar Response to Mat Pilates Training.

Postmenopausal women have a high prevalence of cardiometabolic diseases and that may associate with higher oxidative stress. Exercise can contribute to the treatment of such diseases, but some modalities, such as Mat Pilates, need to be further studied in terms of their physiological responses. Our aim was to investigate the effects of 12 weeks of Mat Pilates on redox status in postmenopausal women with one or multiple comorbidities of cardiometabolic diseases. Forty-four postmenopausal women were divided into two groups: SINGLE, composed of women with one cardiometabolic disease (n = 20) and MULT, with multimorbidity (n = 24). Mat Pilates training was conducted three times a week for 12 weeks, and each session lasted 50 min. Plasma samples were collected before and after training to analyze the following redox markers: superoxide dismutase, catalase, glutathione peroxidase, total antioxidant capacity due to ferric-reducing antioxidant power (FRAP), reduced glutathione (GSH), uric acid, and carbonyl protein. ANCOVA showed interaction effects in FRAP (p = 0.014). Both groups had reduced levels of catalase (p = 0.240) and GSH (p = 0.309), and increased levels of carbonyl protein (p = 0.053) after intervention. In conclusion, the redox status of postmenopausal women shows no changes mediated by Mat Pilates training between SINGLE and MULT, except for greater reductions of FRAP in SINGLE.

Neutrophil-lymphocyte Ratio and C-Reactive Protein Levels are not Associated with Strength, Muscle Mass, and Functional Capacity in Kidney Transplant Patients.

Chronic inflammation has been associated with components of sarcopenia; however, these associations are unknown in kidney transplant patients (KTPs). The aim of this study was to associate neutrophil-lymphocyte ratio (NLR) and C-reactive protein (CRP) with strength, muscle mass, and functional capacity in KTPs. A cross-sectional study evaluating 108 KTPs was performed. Strength was evaluated by handgrip strength and five-times-sit-to-stand test (5STS), and appendicular skeletal muscle mass (ASM) was estimated by bioelectrical impedance analysis. The ASM index (ASMI) was calculated using the ASM (kg)/height (m2). Functional capacity was assessed by the 4-m gait speed test and short physical performance battery (SPPB). The electrochemiluminescence method was used for analyzing CRP levels, and the cytometric method XN-3000 Sysmex was used for obtaining leukogram values to calculate the NLR. Linear regression analysis was used to assess the association between systemic inflammation and sarcopenia components, adjusting for confounders. NLR and CRP levels were not associated with handgrip strength (ß = - 0.231, p = 0.389; ß = - 0.291, p = 0.577), 5STS (ß = - 0.114, p = 0.288; ß = - 0.202, p = 0.334), ASM (ß = - 0.027, p = 0.813; ß = 0.062, p = 0.788), ASMI (ß = - 0.036, p = 0.242; ß = 0.040, p = 0.505), 4-m gait speed (ß = 0.013, p = 0.082; ß = 0.004, p = 0.769), and SPPB (ß = 0.076, p = 0.170; ß = 0.152, p = 0.157), respectively. In conclusion, NLR and CRP levels were not associated with muscle mass, strength, and functional capacity in KTPs.

Sex and population-specific cutoff values of muscle quality index: Results from NHANES 2011-2014.

BACKGROUND & AIMS: Muscle quality index (MQI) is used to measure the quality of the muscles. It is defined as the ratio of muscle strength per unit of muscle mass, but since this might vary by rage and ethnicity, we aimed to develop sex, and population-specific normative data and cutoff values for MQI (extremally low and low) using the arm or appendicular skeletal muscle mass (ASM) obtained from a population-representative sample. METHODS: This cross-sectional analysis included data from 4849 volunteers (aged 20-59 years) from the National Health and Nutrition Examination Survey (NHANES) 2011-2014. Measures of handgrip strength (HGS) were performed using a hand dynamometer. ASM was assessed by dual-energy X-ray absorptiometry (DXA). Arm ASM mass was used to calculate MQIArm [dominant HGS/dominant arm ASM (kg/kg)]; ASM was used to calculate MQIApp [dominant HGS/ASM (kg/kg)]; and the sum of the non-dominant hand and dominant hand were used to calculate MQItotal [HGS sum/ASM (kg/kg)]. Cutoff values were derived from a young reference subgroup (n = 1625 aged, 20-39 years), with low and extremely low MQI defined as 1 and 2 sex-specific standard deviations below the mean, respectively. RESULTS: MQIArm, MQIApp, and MQITotal differed by sex and population studied. Overall, using the proposed cutoffs, men showed lower values of MQIArm than women, and higher MQIApp, and MQITotal values. Compared to non-Hispanic Whites, non-Hispanic Asians had higher values of MQI while non-Hispanic Black people had lower values. CONCLUSION: MQIs cutoffs were established for both sexes and different populations studied. MQIArm, MQIApp, and MQITotal values were lower after the fifth-decade in men, but not in women.

Plasma omega-3 is not associated with appendicular muscle mass index in young and middle-aged individuals: Results from NHANES 2011-2012.

The aim of this study was to evaluate the association between plasma omega-3 (ω-3) and appendicular muscle mass index (AMMI) in young and middle-aged individuals; and also to evaluate whether these associations are sex-specific. A cross-sectional study was performed evaluating 1037 individuals aged 20 to 59 years from a sub-sample of the National Health and Nutrition Examination Survey (NHANES) 2011-2012. Plasma ω-3 was evaluated by gas chromatography-mass spectrometry and lean mass was assessed by dual-energy x-ray absorptiometry (DXA). Total plasma ω-3, docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and alpha-linolenic acid (ALA) were not associated with AMMI in total sample, men and women after adjustments for confounders. Plasma ω-3 and its subtypes were not associated with AMMI in a subanalysis evaluating young (20 to 44 y) and middle-aged (45 to 59 y) individuals separately. In conclusion, plasma ω-3 fatty acids are not associated with AMMI in young and middle-aged individuals regardless of sex.

Single and Serial Carbohydrate Mouth Rinsing Do Not Improve Yo-Yo Intermittent Recovery Test Performance in Soccer Players.

Carbohydrate (CHO) mouth rinsing seems to improve performance in exercises lasting 30-60 min. However, its effects on intermittent exercise are unclear. It is also unknown whether serial CHO mouth rinses can promote additional ergogenic effects when compared with a single mouth rinse. The aim of this study was to evaluate the effect of single and serial CHO mouth rinses on Yo-Yo Intermittent Recovery Test Level 1 (Yo-Yo IR1) performance in soccer players. In a randomized, crossover, double-blind, placebo-controlled design, 12 male (18.9 ± 0.5 years) soccer players performed eight serial mouth rinses under three different conditions: placebo solution only (noncaloric juice), seven placebo mouth rinses plus a single CHO mouth rinse (8% maltodextrin), or eight CHO mouth rinses (8-CHO). Following the final mouth rinse, individuals performed the Yo-Yo IR1 test to evaluate the maximal aerobic endurance performance measured via total distance covered. There were no differences in Yo-Yo IR1 performance between sessions (p = .32; single CHO mouth rinse (8% maltodextrin): 1,198 ± 289 m, eight CHO mouth rinses: 1,256 ± 253 m, placebo: 1,086 ± 284 m). In conclusion, single and serial CHO mouth rinsing did not improve performance during the Yo-Yo IR1 for soccer players. These data suggest that CHO mouth rinsing is not an effective ergogenic strategy for intermittent exercise performance irrespective of the number of rinses.

Prevalence of sarcopenia according to EWGSOP1 and EWGSOP2 in older adults and their associations with unfavorable health outcomes: a systematic review.

BACKGROUND: The European Working Group on Sarcopenia in Older People (EWGSOP) recently updated the definition and diagnostic criteria to assess sarcopenia, which can result in important changes in sarcopenia prevalence in older adults. AIM: To compare the prevalence of sarcopenia through the diagnostic criteria and definition proposed by the first (EWGSOP1) and recent (EWGSOP2) European consensus in older adults. We also aimed to evaluate which sarcopenia consensus is better associated with unfavorable health outcomes. METHODS: The review followed PRISMA guidelines. Embase, Medline (PubMed), Scopus and Web of Science were searched from 2018 to February 2021. The systematic review protocol was registered at PROSPERO (CRD42020213303). The search, selection, and evaluation processes were done in a duplicate and independent manner. RESULTS: Of the 298 potentially eligible articles, 9 were included in this review. The prevalence of sarcopenia was 17.7% by EWGSOP1 and 11% by EWGSOP2. Evaluating all the studies, the sarcopenia prevalence ranged from 6.2 to 35.3% for the EWGSOP1, and from 3.2 to 26.3% for the EWGSOP2. Five studies have evaluated the association between the prevalence of sarcopenia (EWGSOP1 versus EWGSOP2) and unfavorable health outcomes, in which three studies showed that EWGSOP1 was better associated with increased risk of hospitalization and/or mortality. CONCLUSION: In comparison with EWGSOP1, the prevalence of sarcopenia in older adults decreased when diagnosed according to EWGSOP2. Based on limited evidence, EWGSOP2 seems to be worse for predicting unfavorable outcomes compared with EWGSOP1.

The Effect of Whole Egg Intake on Muscle Mass: Are the Yolk and Its Nutrients Important?

Whole egg may have potential benefits for enhancing muscle mass, independent of its protein content. The yolk comprises ∼40% of the total protein in an egg, as well as containing several nonprotein nutrients that could possess anabolic properties (e.g., microRNAs, vitamins, minerals, lipids, phosphatidic acid and other phospholipids). Therefore, the purpose of this narrative review is to discuss the current evidence as to the possible effects of egg yolk compounds on skeletal muscle accretion beyond those of egg whites alone. The intake of whole egg seems to promote greater myofibrillar protein synthesis than egg white intake in young men. However, limited evidence shows no difference in muscle hypertrophy when comparing the consumption of whole egg versus an isonitrogenous quantity of egg white in young men performing resistance training. Although egg yolk intake seems to promote additional acute increases on myofibrillar protein synthesis, it does not seem to further enhance muscle mass when compared to egg whites when consumed as part of a high-protein dietary patterns, at least in young men. This conclusion is based on very limited evidence and more studies are needed to evaluate the effects of egg yolk (or whole eggs) intake on muscle mass not only in young men, but also in other populations such as women, older adults, and individuals with muscle wasting diseases.

Association Between Dietary Intake and Serum Uric Acid Levels in Kidney Transplant Patients.

OBJECTIVES: The aim of this study was to evaluate the association between dietary intake and uric acid (UA) levels in kidney transplant patients (KTPs). METHODS: A cross-sectional study was performed with 113 KTPs. Dietary intake assessment was carried out thorough two 24-hour dietary recalls using the 5-step multiple pass method. We evaluated the intake of energy, carbohydrate, total protein, animal protein, vegetable protein, total fat, saturated fat, trans fat, monounsaturated fat, polyunsaturated fat, omega-3 and omega-6 fatty acids, cholesterol, total sugar, added sugars, total fiber, insoluble fiber, soluble fiber, alcohol, caffeine, fructose, glucose, lactose, sucrose, vitamin A, vitamin C, vitamin E, and calcium. The intake of several food groups (portions) was also evaluated. Hyperuricemia was classified as >7.0 and >6 mg/dL for men and women, respectively. RESULTS: In odds ratio analyses, the individuals who ingested more vegetable protein (g/kg) and caffeine (mg) presented lower chance to have hyperuricemia. In linear regression, animal protein (g) intake was positively associated (ß = 0.011, P = .048), while vegetable protein (g/kg) intake was inversely associated (ß = -2.45, P = .047) with serum UA. However, after a multiple linear regression including vegetable and animal protein intakes together, only vegetable protein intake remained associated with UA. The intake of other nutrients and portions of food groups was not associated with UA. All the analyses were adjusted for sex, age, hypertension, body mass index, glomerular filtration rate, use of medicines, and caloric intake misreporting. CONCLUSIONS: Vegetable protein and caffeine intakes were inversely associated with UA in KTPs.

Effects of two different doses of carbohydrate ingestion on taekwondo-related performance during a simulated tournament.

BACKGROUND: Carbohydrate (CHO) ingestion enhances exercise performance; however, the efficacy of CHO intake on repeated bouts of exercise simulating a taekwondo tournament is unknown. Therefore, the purpose was to compare the effects of two different doses of CHO on a sports-specific kicking test during a simulated taekwondo tournament compared to placebo (PLA). METHODS: In a double-blind, randomized-placebo controlled, cross-over trial, eleven junior male professional taekwondo athletes (age: 16 ± 0.8 years, body mass: 55.3 ± 7.3 kg) ingested one of three solutions: (i) high dose (C45): 45 g of CHO (60 g∙h- 1), (ii) low dose (C22.5): 22.5 g of CHO (30 g∙h- 1; both solutions containing 2:1 glucose:fructose), or a PLA immediately following each kicking test. The kicking test was repeated 5 times, separated by 45 mins of rest, simulating a typical taekwondo competition day. Ratings of perceived exertion (RPE) and gastrointestinal discomfort (GI) scores were collected immediately after, and blood glucose before each test. RESULTS: The results revealed that C45 and C22.5 did not improve total, successful, or percentage of successful kicks compared to PLA (p > 0.05). Blood glucose was significantly higher following both CHO conditions compared with PLA across all five tests (p < 0.05). There were no differences between treatments or across tests for RPE (p > 0.05). CONCLUSION: CHO intake, independent of the dose, did not alter taekwondo kick performance during a simulated taekwondo tournament.

Beetroot juice intake with different amounts of nitrate does not change aerobic exercise-mediated responses in heart rate variability in hypertensive postmenopausal women: A randomized, crossover and double-blind study.

OBJECTIVES: To compare the acute effects of a single dose of beetroot juice (BJ) with different concentrations of nitrate (NO3 -) on heart rate variability (HRV) in postmenopausal hypertensive women. METHODS: Thirteen hypertensive postmenopausal women (58.1 ± 4.6 years of age and 27 ± 4 kg/m2 of BMI) completed the protocol that consisted of three visits with different beverage intakes in a randomized and crossover design. The three beverages were BJ with a high content of nitrate (high-NO3 -), BJ with a low content of nitrate (low-NO3 -), and an orange flavored non-caloric drink (OFD). Heart rate (HR) were evaluated during 20 min after sitting rest at 7:20 a.m. (baseline), after they drank one of the drinks, and remained at sitting rest for 120 min and then performed 40 min of aerobic exercise at 65-70% of the HR reserve on a treadmill. HR was recorded for 90 min after exercise for time, frequency, and non-linear domains of HRV index analysis. RESULTS: Two-way ANOVA showed that there were no interaction effects (time∗sessions) in any of the HRV indexes after exercise in all three sessions. HRV indexes increased after exercise (p = <0.05) similarly in all three sessions when compared with the baseline time point. CONCLUSION: Therefore, a single dose of BJ, independent of NO3 - content, does not change aerobic exercise-mediated responses in HRV indexes in hypertensive postmenopausal women.

Serum uric acid is positively associated with muscle strength in older men and women: Findings from NHANES 1999-2002.

BACKGROUND: One of the causes of strength loss in older adults is the increased oxidative stress; thus, substances with antioxidants properties may have protective effects on muscle strength. Uric acid (UA) is an important antioxidant and it seems to be positively associated with muscle strength in older adults; however, the current evidence is still limited. AIM: To investigate whether serum UA is associated with muscle strength in older men and women. METHODS: A cross-sectional study was performed evaluating older adults aged from 50 to 85 years from National Health and Nutrition Examination Survey (NHANES) 1999-2000 and 2001-2002. A total of 2361 individuals (1256 men and 1105 women) were evaluated. The peak isokinetic knee extensor strength was assessed by kinetic communicator isokinetic dynamometer; while UA levels were measured by colorimetric method. Linear regression analyses were performed to estimate the coefficients and 95% confidence intervals for muscle strength by quintiles of UA levels, adjusted for potential confounders. RESULTS: In the unadjusted analyses, serum UA was positively associated with peak force in men and total sample, but not in women. However, after adjustments for confounders, UA levels were positively associated with peak force in total sample (p-trend = 0.007), men (p-trend = 0.044) and women (p-trend = 0.016). CONCLUSION: Serum UA is positively associated with muscle strength in older men and women. These results suggest that UA levels seem to be a protective factor for muscle strength in older adults independent of the sex.