Sex-dependent association of serum vitamin D with muscle strength in older adults: NHANES 2001-2002.

BACKGROUND: Although several studies have suggested a potential positive association between serum vitamin D levels and muscle strength in older adults, it remains unclear whether this relationship is sex-dependent. AIM: To evaluate the association between serum 25 hydroxyvitamin D [25(OH)D] levels and muscle strength in older adults and to assess whether this association is dependent on sex. METHODS: This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) conducted between 2001 and 2002. A total of 1173 individuals aged 50-85 years (630 men and 543 women) were included in the analysis. The peak isokinetic force of the knee extensor was assessed using a kinetic communicator isokinetic dynamometer. Serum 25(OH)D levels were measured using the standardized liquid chromatography-tandem mass spectrometry method. Linear regression analyses were conducted to estimate coefficients and 95% confidence intervals for muscle strength across tertiles of serum vitamin D levels, adjusting for potential confounders. RESULTS: Tertiles of serum vitamin D were positively associated with muscle strength in older men (p-trend = 0.007), whereas no association was observed in older women (p-trend = 0.140) or in the total sample (men and women together; p-trend = 0.139). CONCLUSION: Serum vitamin D levels were positively associated with muscle strength specifically in older men, whereas no association was observed in older women. These results suggest that the relationship between vitamin D and strength may be sex-dependent.

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.

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.

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.

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.

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.

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.

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.

Calcium intake is inversely associated with body fat in postmenopausal women.

BACKGROUND & AIMS: Calcium intake seems to be inversely associated with body fat in several populations; however, little is known about this relationship in postmenopausal women. This study aimed to associate calcium intake with body fat mass in postmenopausal women. METHODS: A cross-sectional study was performed with 107 postmenopausal women who entered in a lifestyle change program. The dietary intake was estimated through three 24-h food recalls. Body fat mass was evaluated by dual-energy X-ray absorptiometry (DXA). Linear regression analyzes were performed associating body fat variables (total fat mass, body fat percentage, trunk fat, gynoid and android fat mass; and body mass index) with calcium intake. RESULTS: After adjustments for age; carbohydrate, protein, lipids and fiber intakes; and physical activity, it was observed that calcium intake (mg/day) was inversely associated with total fat mass (kg and percentage), trunk fat mass (kg), gynoid and android fat mass (kg). Calcium intake was not associated with body mass index, although a tendency was observed (p = 0.062). CONCLUSION: Calcium intake was inversely associated with body fat mass in postmenopausal women.

Serum Uric Acid Is Positively Associated with Muscle Mass and Strength, but Not with Functional Capacity, in Kidney Transplant Patients.

BACKGROUND: Our aim was to associate serum uric acid (UA) with muscle mass, strength and functional capacity in kidney transplant patients (KTPs). METHODS: A cross-sectional study was performed on 113 KTPs. The fat-free mass and total and appendicular muscle mass were estimated by performing a bioelectrical impedance analysis. The strength was evaluated using the handgrip strength test (HGS) and the five times sit to stand test (5STS). The functional capacity was evaluated using the 4 m walk test and the short physical performance battery (SPPB). RESULTS: Linear regression showed that the UA levels were positively associated with the muscle mass, fat-free mass, appendicular muscle mass, muscle mass index and appendicular muscle mass index. The 5STS results (seconds) were inversely associated with the UA levels, showing that individuals with higher UA were more likely to have more strength. However, UA was not associated with the HGS, 4 m walk test and SPPB results. CONCLUSION: UA levels were positively associated with muscle mass and strength, but not with functional capacity, in KTPs.

Body Mass Index, waist circumference or sagittal abdominal diameter: Which parameter is better correlated with body fat changes in postmenopausal women after combined training protocol?

OBJECTIVE: We aimed to verify whether exercise-induced changes in body mass index (BMI), waist circumference (WC) and sagittal abdominal diameter (SAD) are correlated with changes in body fat (BF) in postmenopausal women. METHODS: Seventeen postmenopausal women performed combined training three times a week, for 12 weeks. Correlations of delta (Δ) BMI, Δ WC, and Δ SAD with Δ total BF, Δ android and Δ gynoid fats were performed. RESULTS: Weight, BMI and android fat decreased over time. A tendency of reductions in gynoid fat was found (p = 0.070). Delta BMI was positively correlated with Δ total BF (r = 0.56; p < 0.05), Δ android fat (r = 0.64; p < 0.05), and Δ gynoid fat (r = 0.72; p < 0.05). The Δ WC was only correlated with Δ gynoid fat (r = 0.55; p < 0.05). The Δ SAD was not correlated with all the Δ body fat parameters evaluated. CONCLUSION: We conclude that changes in BMI were better associated with body fat changes induced by combined training when compared to WC and SAD in postmenopausal women. The patients were part of a 12-week training study (ClinicalTrials.gov Identifier: NCT03200639).

Association between omega-3 fatty acids intake and muscle strength in older adults: A study from National Health and Nutrition Examination Survey (NHANES) 1999-2002.

BACKGROUND: Muscle strength is a predictor of mortality in older adults and some dietary components are associated with this variable; however, little is known about the association between omega-3 fatty acids (ω-3) intake and strength in older adults. OBJECTIVE: To assess whether ω-3 intake is associated with muscle strength in individuals over 50 years. We also aimed to evaluate whether an isocaloric substitution of dietary fatty acids types by ω-3 intake could be associated with muscle strength. METHODS: This study included older adults aged from 50 to 85 y, from National Health and Nutrition Examination Survey (NHANES) 1999-2000 and 2001-2002. A total of 2141 individuals (1119 men and 1022 women) were evaluated and provided complete and reliable dietary intake and isokinetic strength of the knee extensors (peak force) data. Linear regression analysis was conducted without (Model 1) and with adjustments (Model 2). Isocaloric substitution analysis was performed to evaluate whether the substitution of polyunsaturated (excluding ω-3), monounsaturated, saturated fats and ω-6 by consumption of ω-3 is associated with strength. RESULTS: Total ω-3, docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and alpha-linolenic acid (ALA) intakes were positively associated with peak force in men (Model 1). However, after the adjustments for confounders (Model 2), only total ω-3 intake remained significant. Ω-3 intake was not associated with strength in women. The isocaloric substitution of saturated, polyunsaturated, monounsaturated fats and ω-6 by ω-3 was not associated with peak force. CONCLUSION: The intake of total ω-3 was positively associated with muscle strength in older men, but not in older women. In addition, the substitution of other fatty acids by ω-3 intake was not associated with strength.

Protein timing has no effect on lean mass, strength and functional capacity gains induced by resistance exercise in postmenopausal women: A randomized clinical trial.

BACKGROUND & AIMS: Short-term studies have shown that protein intake immediately post-exercise increases muscle protein synthesis. However, the effect of protein timing (comparing protein intake post-exercise vs. several hours after exercise) on lean mass and strength gains in long-term studies is still not fully elucidated. Thus, the aim of our study was to evaluate the effect of protein timing on lean mass, strength and functional capacity gains induced by resistance exercise in postmenopausal women. METHODS: Thirty-four postmenopausal women (60.9 ± 6.7 years) participated in this double-blind, parallel-group, randomized clinical trial. All individuals performed the same resistance training protocol in the morning, 3 times a week, at 70% of 1-maximum repetition (1-RM), over 8 weeks. Participants were randomly assigned to protein-carbohydrate group (PC) (n = 17), that ingested 30 g of whey protein immediately after exercise and 30 g of maltodextrin in the afternoon; and to carbohydrate-protein group (CP) (n = 17), that ingested 30 g of maltodextrin immediately after exercise and 30 g of whey protein in the afternoon. Lean mass was assessed using dual-energy X-ray absorptiometry, handgrip strength by a dynamometer, and strength was evaluated by 1-RM of bench press and leg extension. One mile walk test was performed to assess the functional capacity. RESULTS: Both the PC group (37.3 [35.0-39.7] to 38.1 [35.9-40.5] kg) and the CP group (38.2 [36.0-40.5] to 38.8 [36.5-41.3] kg) increased the total lean mass (p < 0.001). An increase was also observed in both groups for 1-RM bench press, 1-RM leg extension and handgrip strength (p < 0.001). In addition, the time of 1-mile walk test decreased in both groups (p = 0.019). No differences were noted for group and time interaction for these variables (p > 0.05). CONCLUSION: Protein timing has no effect on lean mass, strength and functional capacity gains induced by resistance exercise in postmenopausal women. This trial was registered at ClinicalTrials.gov as NCT03372876.

Association of phase angle with sarcopenia and its components in physically active older women.

OBJECTIVE: The aim of the present study was to associate phase angle (PhA) with sarcopenia and its components in physically active older women. METHODS: A cross-sectional study was performed with 94 physically active older women. PhA and muscle mass were assessed by bioelectrical impedance. Muscle strength was measured by handgrip strength (HGS) and functional capacity was evaluated by 4-meter walk test. Sarcopenia was diagnosed according to the European Consensus on Definition and Diagnosis of Sarcopenia (2010). Participants were evaluated according to the PhA tercile. The individuals were divided into two groups: 1st vs. 2nd and 3rd terciles. The individuals in the first tercile were considered having low PhA (< 5.7º). RESULTS: Low PhA was not associated with sarcopenia (OR = 1.50 (0.520-4.319)), low muscle mass index (OR = 1.50 (0.520-4.319)), low HGS (OR = 3.15 (0.954-10.401)) and low walk speed (OR = 1.46 (0.384-5.534)). In addition, PhA had a weak correlation with walk speed (r = 0.24, p = 0.023) and walk speed was able to predict the PhA variations by 3.9%. CONCLUSION: PhA was not associated with sarcopenia and its components in physically active older women. Although PhA was correlated with walk speed, the biological meaning of this association is questionable, since the power of the prediction was low.

Moderate Increase in Protein Intake Promotes a Small Additional Improvement in Functional Capacity, But Not in Muscle Strength and Lean Mass Quality, in Postmenopausal Women Following Resistance Exercise: A Randomized Clinical Trial.

The aim of this study was to evaluate the effect of a moderate increase in protein intake on muscle strength, functional capacity and lean mass quality improvements in postmenopausal women following resistance exercise. Forty-seven postmenopausal women were randomized in two groups: Normal protein (NP, n = 25), who received a dietary plan containing ~0.8 g protein·kg-1·d-1 (recommended dietary allowance-RDA recommendations); and higher protein (HP, n = 22), which a moderate increase in protein intake was recommended (~1.2 g protein·kg-1·d-1). Resistance training was performed for 10 weeks, three times/week. Muscle strength (handgrip strength and one repetition maximum test-1-RM), functional capacity and lean mass (LM) quality (muscle strength to lean mass ratio) were evaluated. Dietary intake was assessed by nine 24 h food recalls. After intervention, both groups increased similarly the leg extension 1-RM and handgrip strength. Regarding functional capacity tests, both groups increased the balance test score (SPPB) and 10 m walk test speed, with no differences between the groups. In addition, an increase in speed to perform the 6 min and 400 m walk tests was observed over the time, with an additional improvement in the HP group (time × group interaction; p = 0.007 and p = 0.004, respectively). About LM quality, leg extension 1-RM/leg LM improved over the time in both groups (p = 0.050), with no time × group interaction. All these significant changes had a low effect size. In conclusion, a moderate increase in protein intake promoted a small additional improvement in functional capacity, but it did not induce a greater increase in strength and LM quality after 10 weeks of resistance exercise in postmenopausal women. This trial was registered at ClinicalTrials.gov as NCT03024125.

No Improvement in Running Time to Exhaustion at 100% VO2max in Recreationally Active Male Runners With a Preexercise Single-Carbohydrate Mouth Rinse.

BACKGROUND: Carbohydrate (CHO) mouth rinse has been used as an ergogenic strategy due to its central effect; however, the effects of this intervention during short-duration high-intensity exercises are not fully understood. PURPOSE: To investigate the effect of CHO mouth rinse on time to exhaustion in a short-duration high-intensity exercise performed on a treadmill. METHODS: A randomized double-blind, placebo-controlled, crossover study was conducted with 10 (24.1 [4.3] y) recreationally active male runners. The protocol consisted of a warm-up at 65% of VO2max for 5 min followed by 3 min passive rest. At the end of this rest period, the individuals performed their mouth rinse either with CHO (maltodextrin, 6%) or with placebo (industrialized noncaloric juice with the same taste). Immediately after mouth rinse, the subjects ran at velocity equivalent to 100% of individual VO2max until voluntary exhaustion. The perceived effort was obtained through a Borg scale. Blood lactate was quantified before and after the protocol, and heart rate was evaluated during the protocol. RESULTS: No difference was found (P = .90) in time to exhaustion between placebo (193.9 [46.5] s) and CHO mouth rinse (195.1 [51.8] s). Blood lactate, heart rate, and perception of effort increased in both groups, but with no differences (all variables, P > .05) between groups. CONCLUSION: The findings showed that a preexercise single-CHO mouth rinse was ineffective to improve running time to exhaustion at velocity equivalent to 100% VO2max on a treadmill in recreationally active male runners.

Comparison of predictive equations of lean mass in young and postmenopausal women.

BACKGROUND AND AIM: The lean mass (LM) is a predictor of functional capacity, quality of life, and mortality. In this way, the LM should be measured by reliable methods. However, it presents high cost and generally predictive equations are used in clinical practice, but little is known which is the best predictive equation of LM in women. The purpose of the present study was to verify which predictive equation of LM correctly estimates the LM in young and postmenopausal women. METHODS: Eighty-one women aged 19-81 years were evaluated. Body weight, height, waist circumference, and skin folds (bicipital, tricipital, subscapular and suprailiac) were measured. The LM was evaluated by DXA and also estimated using the predictive equations of Hume I, Hume II, Salamat, Kulkarni I, and Kulkarni II. Bland-Altman analysis was performed to evaluate the over/underestimation of the LM by predictive equations. RESULTS: The equations of Salamat, Kulkarni II, Hume I and Kulkarni I overestimated the LM by 0.0 (7.0; -6.9) kg; 2.3 (7.5; -3.0) kg; 5.1 (9.0; 0.4) kg; and 9.7 (16.3, 3.1) kg, respectively; whereas Hume II equation underestimated the LM by -16.9 (-11.5; -22.2) kg. CONCLUSIONS: The equation that presented a better prediction of LM was Salamat. However, it should be used with caution in clinical practice since this equation showed elevated confidence intervals and limits of agreements, and can lead to significant errors for some individuals.

Higher Protein Intake Does Not Improve Lean Mass Gain When Compared with RDA Recommendation in Postmenopausal Women Following Resistance Exercise Protocol: A Randomized Clinical Trial.

The aim of this study was to evaluate the effect of a higher protein intake on lean body mass (LBM) gain in postmenopausal women practicing resistance exercise and compare it to the Recommended Dietary Allowance (RDA) recommendation. Twenty-three postmenopausal women (63.2 ± 7.8 years) were randomized into two groups. The group with higher protein intake (n = 11) (HP) received a dietary plan with ~1.2 g·kg-1·day-1 of protein, while the normal protein (NP) group (n = 12) was instructed to ingest ~0.8 g·kg-1·day-1 of protein (RDA recommendation). Both groups performed the same resistance training protocol, 3 times a week, with progression of the number of sets (from 1 to 6 sets) and 8-12 repetitions. The intervention occurred over 10 weeks. Body composition evaluation was performed by dual-energy X-ray absorptiometry. The diet was evaluated by nine 24-h food recall summaries over the course of the study. During the intervention period, the HP group presented a higher protein (1.18 ± 0.3 vs. 0.87 ± 0.2 g·kg-1·day-1, p = 0.008) and leucine (6.0 ± 1.4 vs. 4.3 ± 0.9 g/day, p < 0.001) intake than the NP group, respectively. At the end of the intervention, there were increases in LBM both in HP (37.1 ± 6.2 to 38.4 ± 6.5 kg, p = 0.004) and in NP (37.6 ± 6.2 to 38.8 ± 6.4 kg, p < 0.001), with no differences between the groups (p = 0.572). In conclusion, increased protein intake did not promote higher LBM gain when compared to RDA recommendation in postmenopausal women performing resistance exercise during 10 weeks. This trial was registered at ClinicalTrials.gov as NCT03024125.