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ABSTRACT: Cabre, HE, Ladan, AN, Moore, SR, Joniak, KE, Blue, MNM, Pietrosimone, BG, Hackney, AC, and Smith-Ryan, AE. Effects of hormonal contraception and the menstrual cycle on fatigability and recovery from an anaerobic exercise test. J Strength Cond Res 38(7): 1256-1265, 2024-This study sought to evaluate the effects of oral contraceptive (OC) and hormonal intrauterine device (H-IUD) use, compared with a eumenorrheic (EUM) cycle, on fatigability and recovery between hormone the phases. Peak power (PP), average power (AP), fatigue index (FI), blood lactate, vessel diameter, and blood flow (BF) were measured from a repeated sprint cycle test (10 × 6 seconds) in 60, healthy, active women (mean ± SD ; age: 26.5 ± 7.0 years, BMI: 22.5 ± 3.7 kg·m -2 ) who used monophasic OC (≥6 months; n = 21), had a H-IUD (≥6 months; n = 20), or had regular naturally occurring menstrual cycle (≥3 months) or had a nonhormonal IUD (EUM; n = 19). Subjects were randomly assigned to begin in either the low-hormone phase (LHP) or high-hormone phase (HHP) and were tested once in each phase. Separate univariate analyses of covariances assessed the change from HHP to LHP between the groups, covaried for progesterone, with significance set at p ≤ 0.05. All groups demonstrated similar changes in PP, AP, FI, blood lactate, vessel diameter, and BF between the phases ( p > 0.05). Although not significant, AP was higher in LHP for OC (Δ -248.2 ± 1,301.4 W) and EUM (Δ -19.5 ± 977.7 W) and higher in HHP for H-IUD (Δ 369.3 ± 1,123.0 W). Oral contraceptive group exhibited a higher FI (Δ 2.0%) and reduced blood lactate clearance (Δ 2.5%) in HHP. In recreationally active women, hormonal contraception and hormone phases may minimally impact fatigue and recovery. Individual elite female athletes may benefit from understanding hormonal contraception type as performance and recovery may slightly vary across the cycle.
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Teste de Esforço , Ciclo Menstrual , Humanos , Feminino , Ciclo Menstrual/fisiologia , Ciclo Menstrual/efeitos dos fármacos , Adulto , Teste de Esforço/métodos , Adulto Jovem , Ácido Láctico/sangue , Contracepção Hormonal , Fadiga/fisiopatologia , Dispositivos Intrauterinos , Fadiga Muscular/efeitos dos fármacos , Fadiga Muscular/fisiologiaRESUMO
Few investigations have evaluated the validity of current body composition technology among racially and ethnically diverse populations. This study assessed the validity of common body composition methods in a multi-ethnic sample stratified by race and ethnicity. One hundred and ten individuals (55 % female, age: 26·5 (sd 6·9) years) identifying as Asian, African American/Black, Caucasian/White, Hispanic, Multi-racial and Native American were enrolled. Seven body composition models (dual-energy X-ray absorptiometry (DXA), air displacement plethysmography (ADP), two bioelectrical impedance devices (BIS, IB) and three multi-compartment models) were evaluated against a four-compartment criterion model by assessing total error (TE) and standard error of the estimate. For the total sample, measures of % fat and fat-free mass (FFM) from multi-compartment models were all excellent to ideal (% fat: TE = 0·94-2·37 %; FFM: TE = 0·72-1·78 kg) compared with the criterion. % fat measures were very good to excellent for DXA, ADP and IB (TE = 2·52-2·89 %) and fairly good for BIS (TE = 4·12 %). For FFM, single device estimates were good (BIS; TE = 3·12 kg) to ideal (DXA, ADP, IB; TE = 1·21-2·15 kg). Results did not vary meaningfully between each race and ethnicity, except BIS was not valid for African American/Black, Caucasian/White and Multi-racial participants for % fat (TE = 4·3-4·9 %). The multi-compartment models evaluated can be utilised in a multi-ethnic sample and in each individual race and ethnicity to obtain highly valid results for % fat and FFM. Estimates from DXA, ADP and IB were also valid. The BIS may demonstrate greater TE for all racial and ethnic cohorts and results should be interpreted cautiously.
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OBJECTIVES: Fat-free mass (FFM) accounts for ~80% of the variance in resting energy expenditure (REE), and this relationship is complicated by adiposity. The objective was to compare adjusted REE and contributions of skeletal lean mass and fat mass (FM) to adjusted REE in women with varying adiposity levels using a novel approach. METHODS: Women were divided into tertiles by body fat percent (%fat): Tertile 1 (T1): %fat = 18.5%-28.4%; Tertile 2 (T2): %fat = 28.5%-33.8%; Tertile 3 (T3): %fat = 34.0%-61.0%. Outcome measures were measured and adjusted REE, body composition (skeletal lean mass, FM, %fat) from dual-energy X-ray absorptiometry, and percent contribution of skeletal lean mass and FM to adjusted REE. RESULTS: The main effect for tertiles (T1 vs. T2 vs. T3) was significant (p = .001); REE was significantly higher in T3 versus both T1 by 281 kcal/day (p = .001) and T2 by 215 kcal/day (p = .001). Expenditure from skeletal lean mass in T1 was significantly higher than T3 by 3.2% (p = .001). T3 had a significantly higher FM contribution than T1 by 5.1% (p = .001) and T2 by 3.9% (p = .001). CONCLUSIONS: Women with elevated %fat experienced lower skeletal lean mass contribution and higher FM contribution to adjusted REE. FM may explain more of the variance in REE between women of different levels of adiposity.
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Adiposidade , Metabolismo Basal , Absorciometria de Fóton , Composição Corporal , Calorimetria Indireta , Metabolismo Energético , Feminino , Humanos , ObesidadeRESUMO
Understanding the effects of acute feeding on body composition and metabolic measures is essential to the translational component and practical application of measurement and clinical use. To investigate the influence of acute feeding on the validity of dual-energy X-ray absorptiometry (DXA), a four-compartment model (4C) and indirect calorimetry metabolic outcomes, thirty-nine healthy young adults (n 19 females; age: 21·8 (sd 3·1) years, weight; 71·5 (sd 10·0) kg) participated in a randomised cross-over study. Subjects were provided one of four randomised meals on separate occasions (high carbohydrate, high protein, ad libitum or fasted baseline) prior to body composition and metabolic assessments. Regardless of macronutrient content, acute feeding increased DXA percent body fat (%fat) for the total sample and females (average constant error (CE):-0·30 %; total error (TE): 2·34 %), although not significant (P = 0·062); the error in males was minimal (CE: 0·11 %; TE: 0·86 %). DXA fat mass (CE: 0·26 kg; TE: 0·75 kg) and lean mass (LM) (CE: 0·83 kg; TE: 1·23 kg) were not altered beyond measurement error for the total sample. 4C %fat was significantly impacted from all acute feedings (avg CE: 0·46 %; TE: 3·7 %). 4C fat mass (CE: 0·71 kg; TE: 3·38 kg) and fat-free mass (CE: 0·55 kg; TE: 3·05 kg) exceeded measurement error for the total sample. RMR was increased for each feeding condition (TE: 1666·9 kJ/d; 398 kcal/d). Standard pre-testing fasting guidelines may be important when evaluating DXA and 4C %fat, whereas additional DXA variables (fat mass and LM) may not be significantly impacted by an acute meal. Measuring body composition via DXA under less stringent pre-testing guidelines may be valid and increase feasibility of testing in clinical settings.
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High-intensity interval training (HIIT) promotes positive cardiometabolic and body composition changes. Essential amino acids (EAA) may support changes associated with HIIT, but evaluation of potential synergistic effects is lacking. The purpose of this study was to compare independent and combined effects of HIIT and EAA on total body composition and metabolism in men and women considered overweight/obese; an exploratory aim was to evaluate the modulatory effects of sex. Sixty-six healthy adults (50% female; Age: 36.7 ± 6.0 years; BMI: 32.0 ± 4.2 kg/m2) completed 8 weeks of: (1) HIIT, 2 days/weeks; (2) EAA supplementation, 3.6 g twice daily; (3) HIIT + EAA; or (4) control. Body composition, resting metabolic rate (RMR), substrate metabolism (respiratory exchange ratio; RER), and cardiorespiratory fitness were measured at baseline, 4 weeks, and 8 weeks; cardiometabolic blood markers were measured at baseline and 8 weeks. Differences between groups were assessed by linear mixed models covaried for baseline values, followed by 95% confidence intervals (CI) on adjusted mean change scores. There were no significant changes in body composition (p > 0.05) for any group. Changes in RER, but not RMR, occurred with HIIT (mean change; [95% CI]: - 0.04; [- 0.07, - 0.02]) and EAA (- 0.03; [- 0.06, - 0.01]) after 8 weeks. Cardiorespiratory fitness increased following 8 weeks of HIIT (+ 5.1 ml/kg/min [3.3,6.8]) and HIIT + EAA (+ 4.1 ml/kg/min [1.0,6.4]). Changes with HIIT + EAA were not significantly different from HIIT. There were no changes in cardiometabolic markers (p > 0.05) and no sex interaction (p > 0.05). HIIT is efficacious for promoting positive changes in cardiorespiratory fitness and resting substrate metabolism in adults considered overweight/obese. Addition of EAA did not significantly enhance HIIT-induced adaptations. ClinicalTrials.gov ID#NCT04080102.
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Aminoácidos Essenciais/administração & dosagem , Treinamento Intervalado de Alta Intensidade , Obesidade/metabolismo , Sobrepeso/metabolismo , Adulto , Biomarcadores/sangue , Composição Corporal , Índice de Massa Corporal , Aptidão Cardiorrespiratória , Metabolismo Energético , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
ABSTRACT: Cabre, HE, Greenwalt, CE, Gould, LM, Hirsch, KR, Blue, MNM, and Smith-Ryan, AE. Exploring the "Athlete's Paradox": Division I cross-country runners demonstrate similar muscle characteristics to recreationally trained young adults. J Strength Cond Res 35(11): 3213-3217, 2021-Endurance training can influence body composition and muscle characteristics. Endurance athletes have demonstrated elevated intramuscular fat (IMF), yet individuals with greater body fat also demonstrate elevated IMF. The purpose of this study was to examine differences in muscle characteristics (echo intensity [EI] and muscle cross-sectional area [mCSA]) and body composition between Division I collegiate athletes and college-age adults matched for percent fat (%fat). Thirty cross-country athletes (XC) and 30 normal-weight (NW) recreationally active college students (male athletes: n = 30; female athletes: n = 30; mean ± SD: age: 19.2 ± 1.1 years; body mass: 61.7 ± 8.7 kg; %fat: 18.0 ± 5.2%) underwent a panoramic ultrasound scan of the vastus lateralis to evaluate EI and mCSA. A full-body dual-energy x-ray absorptiometry scan was used to assess fat mass (FM), lean mass (LM), and %fat. Independent t-tests were used to evaluate mCSA, EI, and body composition. Significance level was set at ≤ 0.05. There were no significant differences between the XC and NW cohorts in mCSA (mean difference [MD; XC - NW], -1.30 ± -0.40 cm3; p = 0.340) or EI (MD: 3.97 ± 2.66 a.u.; p = 0.478). Body composition was not different between the groups: FM (MD: -0.14 ± -0.54 kg; p = 0.848), LM (-3.07 ± 1.25 kg; p = 0.268), or bone mineral content (-0.21 ± 0.03 kg; p = 0.120). There were also no significant differences for any outcome variables when stratified by male athletes (p = 0.097-0.468) or female athletes (p = 0.055-0.700). These results suggest that XC athletes may have similar muscle characteristics to NW individuals when matched for %fat. Understanding and tracking muscle characteristics in XC athletes may be important for performance, injury prevention, and the transition to retirement.
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Atletas , Composição Corporal , Absorciometria de Fóton , Adolescente , Adulto , Composição Corporal/fisiologia , Feminino , Humanos , Masculino , Músculo Quadríceps/diagnóstico por imagem , Ultrassonografia , Adulto JovemRESUMO
Obesity is a highly prevalent chronic disease that impacts >40% of reproductive-aged females. The pathophysiology of obesity is complex and can be understood simply as a chronic energy imbalance whereby caloric intake exceeds caloric expenditure with an energy surplus stored in adipose tissue. Obesity may be categorized into degrees of severity as well as different phenotypes on the basis of metabolic health and underlying pathophysiology. Obesity and excess adiposity have a significant impact on fertility and reproductive health, with direct effects on the hypothalamic-pituitary-ovarian axis, the ovary and oocyte, and the endometrium. There are significant adverse pregnancy outcomes related to obesity, and excess weight gain before, during, and after pregnancy that can alter the lifelong risk for metabolically unhealthy obesity. Given the high prevalence and pervasive impact of obesity on reproductive health, there is a need for better and individualized care for reproductive-aged females that considers obesity phenotype, underlying pathophysiology, and effective and sustainable interventions to treat obesity and manage weight gain before, during, and after pregnancy.
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Obesidade , Saúde Reprodutiva , Humanos , Feminino , Obesidade/fisiopatologia , Obesidade/metabolismo , Obesidade/epidemiologia , Gravidez , Reprodução/fisiologia , Infertilidade Feminina/fisiopatologia , Infertilidade Feminina/metabolismo , Infertilidade Feminina/terapia , Infertilidade Feminina/etiologia , Infertilidade Feminina/epidemiologia , Metabolismo Energético , Fertilidade/fisiologia , Fatores de Risco , Complicações na Gravidez/fisiopatologia , Complicações na Gravidez/metabolismo , Complicações na Gravidez/epidemiologia , Complicações na Gravidez/etiologia , Complicações na Gravidez/terapia , Resultado da Gravidez/epidemiologia , Fatores Etários , AdultoRESUMO
BACKGROUND: Women can spend up to 40% of their lives in the postmenopausal state. As women begin to transition into menopause, known as perimenopause, changes in hormonal concentrations and body composition dramatically increase overall cardiometabolic risk. Dietary patterns and interventions can be utilized to prevent and treat cardiovascular disease (CVD) and some dietary patterns over others may be more beneficial due to their specific effects on the health aspects of menopause. In this narrative review, we summarize key cardiovascular alterations that occur during the menopause transition and explore current dietary recommendations to address CVD risk as well as explore the new frontier of precision nutrition and the implications for nutrition prescription during menopause. SUMMARY: Popular dietary interventions for CVD such as the Dietary Approaches to Stop Hypertension (DASH) diet and the Mediterranean Diet (MED) have limited data in women following menopause. However, both diets improve CVD risk biomarkers of total cholesterol and low-density lipoprotein cholesterol as well as lower oxidative stress and inflammation and improve endothelial function. As the menopause transition increases the risk for developing metabolic syndrome, insulin insensitivity, and dyslipidemia, the DASH and MED diets may be impactful dietary strategies for mediating CVD risk in menopausal women. However, these are "one-size-fits-all" approaches that neglect individual characteristics such as genetic predisposition and environmental factors. Precision nutrition considers individual factors for nutrition prescription, spanning from evaluating food intake preferences and behaviors to deep phenotyping. Data from a large-scale investigation of the menopause transition suggests nutritional strategies that address postprandial glycemic responses, and the gut microbiome may attenuate some of the unfavorable effects of menopause on CVD risk factors. KEY MESSAGES: Considering menopause, women are a clinical population that would greatly benefit from precision nutrition. Future research should explore the use of machine learning and artificial intelligence in a precision nutrition framework to modify the DASH and MED diets to address adverse effects that occur during the menopause transition are vital for supporting women's health as they age.
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OBJECTIVE: This study characterized the impact of physical activity (light, moderate, and vigorous [VIG] active minutes per day) and body composition (percent body fat [%BF] and fat-free mass index) on total menopausal symptoms (TMSs) in 72 premenopausal, perimenopausal (PERI), or postmenopausal women. METHODS: Activity minutes were collected from wearable fitness trackers. Body composition was evaluated using a whole-body dual-energy x-ray absorptiometry scan. TMSs were quantified using The North American Menopause Society Questionnaire. RESULTS: Significant associations were observed between TMSs and %BF ( r = 0.464, P < 0.001) and VIG ( r = -0.245, P = 0.038). %BF and VIG were significant predictors for TMSs across groups ( R2 = 0.146 and R2 = 0.092, respectively), but only %BF maintained for PERI ( R2 = 0.421, P < 0.001). CONCLUSIONS: %BF predicted nearly half of the variance in PERI TMSs, whereas VIG predicted 9% of the sample variance, demonstrating an important influence of body fat accumulation and intense physical activity in the menopause transition. High-intensity exercise interventions to alleviate body composition changes may also reduce menopausal-related symptoms for PERI women.
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Doenças dos Genitais Femininos , Menopausa , Feminino , Humanos , Composição Corporal , Exercício Físico , Pré-Menopausa , Tecido Adiposo , Absorciometria de FótonRESUMO
The effects of female sex hormones on optimal performance have been increasingly recognized as an important consideration in exercise and sport science research. This narrative review explores the findings of studies evaluating the effects of menstrual cycle phase in eumenorrheic women and the use of hormonal contraception (oral contraceptives and hormonal intrauterine devices) on metabolism, muscular strength, and recovery in active females. Ovarian hormones are known to influence metabolism because estrogen is a master regulator of bioenergetics. Importantly, the menstrual cycle may impact protein synthesis, impacting skeletal muscle quality and strength. Studies investigating muscular strength in eumenorrheic women report equivocal findings between the follicular phase and luteal phase with no differences compared to oral contraceptive users. Studies examining recovery measures (using biomarkers, blood lactate, and blood flow) do not report clear or consistent effects of the impact of the menstrual cycle or hormonal contraception use on recovery. Overall, the current literature may be limited by the evaluation of only one menstrual cycle and the use of group means for statistical significance. Hence, to optimize training and performance in females, regardless of hormonal contraception use, there is a need for future research to quantify the intra-individual impact of the menstrual cycle phases and hormonal contraceptive use in active females.
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This study examined the effects of creatine (Cr) loading on body mass (BM) and fluid markers of total body water (TBW), extra-cellular fluid (ECF), and intra-cellular fluid (ICF) across the menstrual cycle (MC). Thirty moderately active females, either naturally-menstruating (NM) or using hormonal contraceptives (HC), were randomized to Cr (Cr; 4 × 5 g/day of creatine monohydrate for 5 days; n = 15) or a non-caloric placebo (PL; n = 15) using a double-blind, placebo-controlled design, with a menstrual phase crossover. BM, TBW, ECF, and ICF were measured at pre- and post-supplementation in randomized order of follicular phase (FP; NM: MC days 0−8, HC: inactive pill days) or luteal phase (LP; NM: ≤15 days from next projected cycle start date, HC: active pill days) using bioelectrical impedance spectroscopy. Acute hydration status and salivary estrogen were used as covariates. Change in BM was not different between groups across MC ([PL-Cr] Δ 0.40 ± 0.50 kg; p = 0.427) or between MC phase across groups ([FP-LP] Δ 0.31 ± 0.48 kg; p = 0.528). TBW (p = 0.802), ECF (p = 0.373), and ICF (p = 0.795) were not different between supplement groups at pre-supplementation/FP time points. There were no significant differences between the NM and HC subjects at any time point, for any outcome (p > 0.05). Following LP supplementation, significant changes were observed in TBW (Cr: Δ 0.83 ± 0.38 L, PL: Δ −0.62 ± 0.38 L; p = 0.021), ECF (Cr: Δ 0.46 ± 0.15 L, PL: Δ −0.19 ± 0.15 L; p = 0.013), and ICF (Cr: Δ 0.74 ± 0.23 L, PL: Δ −0.02 ± 0.23 L; p = 0.041). These data demonstrate an increase in all fluid compartments in the LP following Cr loading, without observed alterations in body weight for females.
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Creatina , Suplementos Nutricionais , Feminino , Humanos , Peso Corporal , Líquido Extracelular , Compartimentos de Líquidos Corporais , Método Duplo-CegoRESUMO
INTRODUCTION: Chronic pain affects 19% of adults in the United States, with increasing prevalence in active and aging populations. Pain can limit physical activity and activities of daily living (ADLs), resulting in declined mental and social health. Nutritional interventions for pain currently target inflammation or joint health, but few influence both. Collagen, the most abundant protein in the human body and constituent of the extra cellular matrix, is such a nutraceutical. While there have been reports of reductions in pain with short-term collagen peptide (CP) supplementation, there are no long-term studies specifically in healthy middle-aged active adults. PURPOSE: To determine the effects of daily CP consumption over 3, 6, and 9 months on survey measures of pain, function, and physical and mental health using The Knee Injury & Osteoarthritis Outcomes Score (KOOS) and Veterans Rand 12 (VR-12) in middle-aged active adults. METHODS: This study was a double-blind randomized control trial with three treatment groups (Placebo, 10 g/d CP, and 20 g/d CP). RESULTS: Improvements in ADLs (p = .031, ηp2 = .096) and pain (p = .037, ηp2 = .164) were observed with 10 g/d CP over 6 months, although pain only improved in high frequency exercisers (>180 min/week). Additionally, VR-12 mental component scores (MCS) improved with 10 g/d of CP over 3-9 months (p = .017, ηp2 = .309), while physical component scores (PCS) improved with 20 g/d of CP over 3-9 months, but only in females (p = .013, ηp2= .582). CONCLUSION: These findings suggest 10 to 20 g/d of CP supplementation over 6 to 9 months may improve ADLs, pain, MCS, and PCS in middle-aged active adults.
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Atividades Cotidianas , Osteoartrite do Joelho , Pessoa de Meia-Idade , Feminino , Humanos , Adulto , Osteoartrite do Joelho/tratamento farmacológico , Dor/tratamento farmacológico , Peptídeos , Suplementos Nutricionais , Colágeno/uso terapêutico , Resultado do TratamentoRESUMO
BACKGROUND: Citrulline may amplify the effects of L-arginine and nitric oxide concentration, which may augment vasodilation and blood flow, thereby enhancing aerobic exercise performance. The purpose of this randomized, double-blind, placebo-controlled crossover study was to investigate effects of L-citrulline + Glutathione on aerobic exercise performance and blood flow in well-trained men. METHODS: Twenty-five males (Mean ± SD; Age: 22.2 ± 2.4 yrs; Height: 177.0 ± 4.8 cm; Weight: 75.3 ± 6.9 kg) were randomly assigned to the L-citrulline + Glutathione (Setria Performance Blend: SPB; L-citrulline [2 g] + glutathione [200 mg], 6 capsules) or placebo (PL; 3.1 g cellulose, 6 capsules) group. Participants performed a maximal oxygen consumption treadmill test to determine peak velocity (PV) and returned after eight days of ingesting either PL or SPB. Three timed treadmill runs to exhaustion (TTE) were performed at 90%, 100%, and 110% PV. Brachial artery blood flow and vessel diameter were assessed using ultrasound at 1-hr prior to exercise (1hrPrEX), after each exercise bout, immediately post-exercise (immediate PEX), and 30 minutes post exercise (30minPEX) at visits 2 and 4. Blood analytes were assessed via venous blood draws at visit 1, visit 3, and 1hrPEX, immediate PEX, and 30minPEX at visits 2 and 4. After a 14-day washout, participants repeated the same procedures, ingesting the opposite treatment. Separate repeated measures ANOVAs were performed for TTE, vessel diameter, blood flow, and blood analytes. RESULTS: Blood flow was significantly augmented 30minPEX (p = 0.04) with SPB in comparison with PL. L-citrulline and L-arginine plasma concentrations were significantly elevated immediately PEX (p = 0.001) and 30-minPEX (p = 0.001) following SPB in comparison to PL. CONCLUSION: Acute ingestion of SPB after eight days may enhance blood flow, L-citrulline, and L-arginine plasma concentrations after high-intensity exercise, which may enhance performance. CLINICAL TRIAL REGISTRATION: [https://clinicaltrials.gov/ct2/show/nct04090138], identifier [NCT04090138].
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Citrulina , Suplementos Nutricionais , Masculino , Humanos , Adulto Jovem , Adulto , Citrulina/farmacologia , Estudos Cross-Over , Cápsulas , Glutationa , Método Duplo-Cego , Arginina/farmacologiaRESUMO
INTRODUCTION: The menopause transition yields significant physiological alterations. The purpose was to characterize lean soft tissue (LST), muscle size (muscle cross-sectional area (mCSA)), muscle quality (echo intensity (EI)), and strength across the menopause transition. A secondary aim was to evaluate whole-body protein turnover in a subsample of women. METHODS: Seventy-two healthy women were enrolled in this cross-sectional study based on menopause stage (PRE: n = 24; PERI: n = 24; POST: n = 24). Whole-body LST was measured via dual-energy x-ray absorptiometry, and muscle characteristics (mCSA and EI) were measured via B-mode ultrasound of the vastus lateralis. Maximal voluntary contractions (N·m) of the knee extensors were evaluated. Physical activity (in minutes per day) was accounted for using the International Physical Activity Questionnaire. A subsample of women ( n = 27) ingested 2.0 g of 15 N-alanine to determine whole-body net protein balance (NB; in grams per kilogram of body mass per day). RESULTS: Significant differences were evident in LST ( P = 0.022), leg LST ( P = 0.05), and EI ( P = 0.018) between menopause stages. Bonferroni post-hoc comparisons revealed greater LST in PRE versus PERI (mean difference (MD) ± SE, 3.8 ± 1.5 kg; P = 0.048) and POST (3.9 ± 1.5 lb; P = 0.049). Similarly, EI was significantly higher in PERI PRE (MD, 18.3 ± 7.1 a.u.; P = 0.036). There was no significant difference in mCSA ( P = 0.082) or in maximal voluntary contraction ( P = 0.167). NB was significantly different across groups ( P = 0.026); NB was greater in PRE compared with PERI (MD, 0.39 ± 0.17 g·kg -1 ; P = 0.090), and from PRE to POST (MD, 0.46 ± 0.17 g·kg -1 ; P = 0.042). Physical activity was not significantly different across groups but demonstrated a linear increase from PRE to POST. CONCLUSIONS: The current findings suggest that LST, muscle quality, and protein balance may be negatively influenced by the menopause transition.
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Composição Corporal , Músculo Quadríceps , Humanos , Feminino , Estudos Transversais , Composição Corporal/fisiologia , Músculo Quadríceps/metabolismo , Absorciometria de Fóton , Menopausa , Músculo Esquelético/fisiologiaRESUMO
OBJECTIVE: To explore the effects of essential amino acid (EAA) supplementation on high-intensity interval training (HIIT) fatigue, perceived exertion, and training progression in overweight and obese adults. A secondary aim was to explore potential sex-differences on these outcomes. METHODS: Thirty-seven untrained adults (51% female; 36.2 ± 5.9 yrs; 35.5 ± 6.7% body fat) completed eight weeks of HIIT, 2d/wk on a cycle ergometer, either with EAA supplementation (HIIT + EAA; 3.6 g of EAA twice daily, 30 minutes pre and post HIIT) or without supplementation (HIIT). Heart rate (HR) and ratings of perceived exertion (RPE) were recorded throughout each session as indices of within training fatigue. Time to exhaustion (TTE) was recorded for the final interval of each session. Workload progression was determined by change in watts. Differences between groups (with and without EAA) were evaluated at 1wk, 4wks, and 8wks by repeated measure ANOVAs (α = 0.05). RESULTS: There were no differences in TTE (p = 0.983) or workload progression (p = 0.655) with EAA supplementation at any time point. HR and RPE within HIIT sessions were not significantly different with EAA supplementation at any time point (p > 0.05). Results were similar when evaluating males and females separately, but in females, RPE was significantly lower with EAA supplementation at 4wks (Δ: 1.1-2.2; p = 0.016). CONCLUSION: EAA supplementation did not extend TTE during exercise or enhance workload progression across eight weeks of HIIT in untrained, overweight and obese adults. However, EAA consumed 30 minutes before exercise may reduce perceived exertion during the first four weeks of training in women, which may have implications for overall exercise enjoyment and long-term adherence.
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Treinamento Intervalado de Alta Intensidade , Adulto , Masculino , Humanos , Feminino , Treinamento Intervalado de Alta Intensidade/métodos , Sobrepeso , Carga de Trabalho , Obesidade , FadigaRESUMO
Creatine supplementation improves anaerobic performance and recovery; however, to date, these outcomes have not been well explored in females. This study evaluated the effect of creatine monohydrate loading on exercise recovery, measured by heart rate variability (HRV) and repeated sprint performance, in women across the menstrual cycle. In this randomized, double-blind, cross-over study, 39 women (mean ± standard deviation: age: 24.6 ± 5.9 years, height: 172.5 ± 42.3 cm, weight: 65.1 ± 8.1 kg, BF: 27.4 ± 5.8%) were randomized to a creatine monohydrate (n = 19; 20 g per day in 4 × 5 g doses) or non-caloric PL group (n = 20). HRV was measured at rest and after participants completed a repeated sprint cycling test (10 × 6 s maximal sprints). Measurements were conducted before and after supplementation in the follicular/low hormone and luteal/high hormone phases. Creatine monohydrate supplementation did not influence HRV values, as no significant differences were seen in HRV values at rest or postexercise. For repeated sprint outcomes, there was a significant phase × supplement interaction (p = 0.048) for fatigue index, with the greatest improvement seen in high hormone in the creatine monohydrate group (-5.8 ± 19.0%) compared to changes in the PL group (0.1 ± 8.1%). Sprint performance and recovery were reduced by the high hormone for both groups. Though not statistically significant, the data suggests that creatine monohydrate could help counteract performance decrements caused by the high hormone. This data can help inform creatine monohydrate loading strategies for females, demonstrating potential benefits in the high hormone phase.
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Creatina , Ciclo Menstrual , Humanos , Feminino , Adolescente , Adulto Jovem , Adulto , Creatina/farmacologia , Estudos Cross-Over , Ciclismo , Suplementos Nutricionais , ProgesteronaRESUMO
Women are the largest consumers of dietary supplements. Dietary supplements can play a role in health and performance, particularly for women. Growing evidence and innovations support the unique physiological and nutrient timing needs for women. Despite the need for more nutrition and exercise-specific research in women, initial data and known physiological differences between sexes related to the brain, respiration, bone, and muscle support new product development and evidence-based education for active women regarding the use of dietary supplements. In this narrative review, we discuss hormonal and metabolic considerations with the potential to impact nutritional recommendations for active women. We propose four potential areas of opportunity for ingredients to help support the health and well-being of active women, including: (1) body composition, (2) energy/fatigue, (3) mental health, and (4) physical health.
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Composição Corporal , Suplementos Nutricionais , Feminino , Humanos , Exercício Físico/fisiologia , Estado NutricionalRESUMO
Introduction: Activities such as high-intensity resistance training (HIRT) and high-intensity interval training (HIIT) may be more time-efficient modes to stimulate rapid changes in performance and body composition. There is little research evaluating the combined effects of HIRT and HIIT on body composition and strength, particularly when paired with nutritional supplementation. Purpose: To evaluate the chronic effects of pre- and post-workout supplementation on body composition and strength, and to understand sex-specific responses. Materials and methods: 64 untrained males (n = 23) and females (n = 41) (mean ± standard deviation; age: 33.2 ± 10.0 years; %fat: 31.6 ± 7.4%) were randomized to either (1) pre-post supplementation [SUP (n = 25); pre = multi-ingredient caffeine/HMB/vit D; post = whey protein/carbohydrates/glucosamine/vitamins], (2) placebo [PL (n = 24); non-caloric], or (3) control [CON (n = 15)]. All participants completed one repetition max (1RM) strength testing for leg press and bench press at baseline and week 6. Estimates of fat mass (FM) and lean mass (LM) were measured via dual energy x-ray absorptiometry. Participants in the SUP or PL group completed a 6-week supervised exercise intervention consisting of a full-body HIRT workout (3 × 6-8 reps) followed by a HIIT treadmill run (6 × 1 min run: 1 min rest) twice per week. Outcomes were evaluated by separate repeated measure ANOVAs (2 × 3). Results: There were no differences in FM between groups or sex (p = 0.133-0.851). LM increased from baseline to post-testing for all groups [Mean difference [MD(Post-Pre) ± Standard Error (SE) = 0.78 ± 0.12 kg; p < 0.001]. While not significant (p = 0.081), SUP gained more LM compared to PL [MD(SUP-PL) ± SE = 3.5 ± 3.3 kg] and CON [MD(SUP-CON) ± SE = 5.2 ± 3.8 kg]. LM increased over time for both males (0.84 ± 0.24 kg; p = 0.003) and females (0.73 ± 0.14 kg; p < 0.001). The SUP group resulted in a significant increase in 1RM leg press compared to the CON group (89.9 ± 30.8 kg; p = 0.015), with no significant differences compared to PL (p = 0.409). The SUP group had greater increases in 1RM bench press compared to the CON group (9.8 ± 1.8 kg; p < 0.001), with no significant differences compared to PL (p = 0.99). Both sexes increased upper- (5.5 ± 0.7 kg; p < 0.001) and lower-body strength (69.8 ± 4.5 kg p < 0.001) with training. Conclusion: Nutrient supplementation timing appears to augment body composition changes and strength compared to control. Pre-/post-nutrient timing may support greater increases in LM and lower- and upper-body strength in both men and women. Clinical trial registration: [https://clinicaltrials.gov/ct2/show/NCT04230824?cond=NCT04230824&draw=2&rank=1], identifier [NCT04230824].
RESUMO
BACKGROUND: The COVID-19 pandemic forced collegiate athletes to train at home, without access to facilities. The purpose of this study was to evaluate the effect of the COVID-19 stay-at-home order on body composition of Division I Football Players, with a secondary aim to evaluate these changes between players with "higher" (>25 kg/m2) and "lower" (<25 kg/m2) Fat-Free Mass Index (kg/m2). METHODS: Body composition of 29 NCAA Division I Football Players (age=21.0±10 yr, Ht=186.7±5.6 cm, body mass=110.5±22.8 kg) were measured spring season (February) and prior to preseason (June). Whole body dual-energy X-ray absorptiometry scans were used to determine regional (arms, legs, trunk) and total body fat mass (FM), lean mass (LM), and fat-free mass (FFM). Fat-Free Mass Index (FFMI) was calculated as (LM+bone mineral content [BMC])/height2); participants were stratified by FFMI higher (N.=16) and lower (N.=13). RESULTS: Total LM (mean difference±standard error: 0.80±1.65 kg, P=0.016) increased from pre- to post-COVID stay-at-home. No significant changes in total FM were seen. Players with lower FFMI showed a significant decrease in trunk FM (-0.55±0.19 kg, P=0.016). Players with higher FFMI showed a significant increase in total LM (0.96±0.42 kg, P=0.038). CONCLUSIONS: These results suggest no detrimental effect on body composition.