Glycated hemoglobin (HbA1c) is independently associated with the bioelectrical impedance phase angle in junior sumo wrestlers: A pilot study.

The study explores the relationship between phase angle (PhA), an indicator of cellular health, and metabolic health parameters among junior sumo wrestlers in Japan. Given the demanding lifestyle and high-energy diets of sumo wrestlers that predispose them to metabolic syndrome post-retirement, this study focuses on a younger cohort. The primary aim is to evaluate if PhA could serve as an early indicator of metabolic health issues within this unique demographic. A total of 14 sumo wrestlers aged 9-17 years were assessed to determine the relationship between PhA and various metabolic markers, including glycated hemoglobin (HbA1c), using a TANITA MC-780A-N body composition analyzer and standard blood tests. Bivariate regression analysis and Pearson's correlation revealed a negative relationship between PhA and HbA1c even after adjusting for age and weight (ß = -0.496, r2 = 0.776, r = -0.756, p = 0.004). The results indicate a significant negative relationship between PhA and HbA1c levels, suggesting that lower PhA values, which indicate poorer cellular integrity, are associated with higher HbA1c levels, signifying impaired glycemic control. These findings underscore the potential of PhA as a valuable biomarker for monitoring metabolic health in young sumo wrestlers, with implications for early intervention and management strategies.

Predictors of Water Turnover in Older Adults: A Doubly Labeled Water- and Triaxial Accelerometer-Based Study.

BACKGROUND: Water is one of the most essential nutrients for life. The water turnover (WT), total body water (TBW), and total energy expenditure (TEE) can be measured using the doubly labeled water (DLW) method. WT and TBW are lower in older adults than in young adults, and the former are susceptible to dehydration, necessitating to identify predictors of the WT in older adults. OBJECTIVES: The current study aimed to examine the association between WT and physical activity, physical function, and body composition in Japanese adults aged ≥65 y and identify predictors for WT in this population. METHODS: This study enrolled 133 older adults (women, n = 61; men, n = 72) aged 65-88 y. WT, TBW, TEE, fat-free mass (FFM), and percent body fat (%Fat) were determined using the DLW method. The fitness age score (FAS) was obtained from 5 physical fitness tests. Physical activity and the step count were assessed using a previously validated triaxial accelerometer. Multiple regression analyses were performed with WT as the dependent variable. RESULTS: WT was positively associated with weight, physical activity level (PAL), moderate-vigorous physical activity, and TEE, and negatively associated with sedentary behavior. We examined potential predictors for WT using age, sex, height, weight, FFM, %Fat, TEE, PAL, and FAS in older Japanese adults. CONCLUSIONS: Our results confirmed that age, sex, weight, FFM, TEE, and PAL are the potential predictors of WT in older Japanese adults aged ≥65 y.

Impact of curcumin supplementation on exercise performance and muscle damage after a soccer match: a double-blind placebo-controlled cross-over study.

PURPOSE: Curcumin ingestion can mitigate muscle damage, soreness, and inflammation following a laboratory-based eccentric exercise. Similar effects were observed in recent field-based studies wherein responses were evaluated after a soccer match. However, various potential confounding factors, such as matching opponent skill levels and daily training conditions, may have influenced the outcomes. In the present study, we investigated whether curcumin intake ameliorates changes in muscle damage markers following a soccer match while controlling for the potential confounding factors. METHODS: Fifteen collegiate athletes were tested in a randomized, double-blind, cross-over manner. They were recruited from the same college soccer team and thus followed the same daily training regimen and competition levels. Furthermore, athletes positioning during matches were counterbalanced. They consumed either 180 mg/day of curcumin or a placebo starting 1 h before the match and continuing for 2 days after a match (two 45-min plays and a 15-min half-time). Muscle soreness, jump performance (including countermovement jump and rebound jump index), and inflammatory and muscle damage markers (high-sensitive C-reactive protein, serum creatine kinase activity, and urinary N-terminal fragment of titin concentration) were evaluated before and after the match. The washout period between matches was set at 1 week. RESULTS: After the match, all markers showed similarity between the placebo and curcumin conditions (all P > 0.208). CONCLUSION: These findings indicate that ingesting 180 mg/day of curcumin may not expedite recovery from muscle damage elicited by soccer matches in collegiate soccer players.

Prevalence of Poor Sleep Quality and its Association with Lifestyle Habits, Competition-Based Activities, and Psychological Distress in Japanese Student-Athletes During the COVID-19 Pandemic.

Objectives The present study clarified the prevalence of poor sleep quality and its relation to lifestyle habits, competitive-based activities, and psychological distress among Japanese student-athletes in the initial pandemic period (2020) and 1 year later (2021). Methods In the present study, student-athletes were defined as individuals belonging to university athletic clubs. The data of two cross-sectional surveys (2020: n = 961 and 2021: n = 711) were collected from student-athletes in 6 universities in Japan. First, the prevalence of poor sleep quality (Pittsburgh sleep quality index score > 5) was investigated. Relationships between poor sleep quality and lifestyle habits, competition-based activities, and psychological distress were then explored using multivariate logistic regression analysis adjusted for age, sex, and body mass index. Results The prevalence of poor sleep quality was 33.6% in 2020 and 36.6% in 2021. Poor sleep quality in 2020 was related to late bedtime, taking supplements before bed, part-time job (no late night), stressors of expectations and pressure from others, and psychological distress, whereas that in 2021 was related to early wake-up time, skipping breakfast, taking caffeinated drinks before bed, use of smartphone/cellphone after lights out, stressors of motivation loss, and psychological distress. Conclusions In both 2020 and 2021, one-third of student-athletes had poor sleep quality and psychological distress was its common risk factor. Lifestyle habits and competition stressors associated with poor sleep quality were pandemic-specific in 2020, but similar to the prepandemic period in 2021.

Nutritional and Training Strategies for Actual Competition in World-Class Japanese Female Wrestler: A Case Report.

Wrestlers have a risk of relative energy deficiency in sports because they believe that they can gain an advantage over their opponents by temporarily adopting weight-making strategies even women. However, precise methods of making weight and the effect of manipulating body mass (BM) on health and performance in female wrestlers have not been reported. Our study aimed to report a case of weight making in a world-class female wrestler, who won the world competition seven times in 5-y and had oligomenorrhea. We obtained the BM, blood, urine, and saliva samples, hand grip strength, subjective condition a month before the match (baseline), and 3-d before the match (day-3), and food and physical activity records during baseline and 10 d before the competition. The wrestler lost 4.7% of BM from baseline to day-3 and 7.6% of BM to the match by method to reduce energy intake and enhance dehydration. Hand grip strength did not change by weight loss. After weigh-in, the wrestler took the recovery food containing 4.9 g/kg BM of carbohydrate. Although these weight strategies may at least contribute to the success of wrestlers, the impact on health needs to be clarified in future studies.

The bioelectrical impedance analysis (BIA) international database: aims, scope, and call for data.

BACKGROUND: Bioelectrical impedance analysis (BIA) is a technique widely used for estimating body composition and health-related parameters. The technology is relatively simple, quick, and non-invasive, and is currently used globally in diverse settings, including private clinicians' offices, sports and health clubs, and hospitals, and across a spectrum of age, body weight, and disease states. BIA parameters can be used to estimate body composition (fat, fat-free mass, total-body water and its compartments). Moreover, raw measurements including resistance, reactance, phase angle, and impedance vector length can also be used to track health-related markers, including hydration and malnutrition, and disease-prognostic, athletic and general health status. Body composition shows profound variability in association with age, sex, race and ethnicity, geographic ancestry, lifestyle, and health status. To advance understanding of this variability, we propose to develop a large and diverse multi-country dataset of BIA raw measures and derived body components. The aim of this paper is to describe the 'BIA International Database' project and encourage researchers to join the consortium. METHODS: The Exercise and Health Laboratory of the Faculty of Human Kinetics, University of Lisbon has agreed to host the database using an online portal. At present, the database contains 277,922 measures from individuals ranging from 11 months to 102 years, along with additional data on these participants. CONCLUSION: The BIA International Database represents a key resource for research on body composition.

Comparison of Bioelectrical Impedance Indices for Skeletal Muscle Mass and Intracellular Water Measurements of Physically Active Young Men and Athletes.

BACKGROUND: Bioelectrical impedance analysis (BIA) is a minimally invasive, safe, easy, and quick technology used to determine body composition. OBJECTIVES: We compared the relationship among impedance indices obtained using single-frequency BIA, multi-frequency BIA, bioelectrical impedance spectroscopy (BIS), and skeletal muscle mass (SMM) of physically active young men and athletes using the creatine (methyl-d3) dilution method. We also compared the SMM and intracellular water (ICW) of athletes and active young men measured using a reference stable isotope dilution and BIS method, respectively. METHODS: We analyzed data from 28 men (mean age, 20 ± 2 y) who exercised regularly. Single-frequency BIA at 5 kHz and 50 kHz (R5 and R50), multi-frequency BIA (R250-5), and BIS (RICW) methods of determining the SMM were compared. The deuterium and sodium bromide dilution methods of obtaining the total body water, ICW, and extracellular water measurements were also used, and the results were compared to those acquired using bioimpedance methods. RESULTS: The correlation coefficients between SMM and L2/R5, L2/R50, L2/R250-5, and L2/RICW were 0.738, 0.762, 0.790, and 0.790, respectively (P < 0.01). The correlation coefficients between ICW and L2/R5, L2/R50, L2/R250-5, and L2/RICW were 0.660, 0.687, 0.758, and 0.730, respectively (P < 0.001). However, the correlation coefficients of L2/R50, L2/R250-5, and L2/RICW for SMM and ICW were not significantly different. CONCLUSIONS: Our findings suggest that single-frequency BIA at L2/R50, multi-frequency BIA, and BIS are valid for assessing the SMM of athletes and active young men. Additionally, we confirmed that the SMM and ICW were correlated with single-frequency BIA, multi-frequency BIA, and BIS. Bioimpedance technologies may be dependable and practical means for assessing SMM and hydration compartment status of active young adult males; however, cross-validation is needed.

Comparison of three type of muscle glycogen loading interventions using a very-high-carbohydrate diet in an elite male racewalker: a case report.

PURPOSE: Muscle glycogen storage before a race is necessary for endurance athletes to achieve the best performance. Generally, the recommended carbohydrate intake for preparation over 90 min of the race is 10-12 g·kg--1·day--1. However, it remains unclear whether an elite athlete with an already high-carbohydrate diet can further increase muscle glycogen through a very-high-carbohydrate intake. Therefore, we compared the effects of three types of glycogen loading in a 28-year-old male athlete who belongs to the top 50 racewalkers in the world, consuming a daily energy intake of 4507 kcal and a carbohydrate intake of 12.7 g·kg--1·day--1. METHODS: The racewalker consumed very-high-carbohydrate diets three times for 2 days each, 13.7 g·kg--1·day--1 for trial 1, 13.9 g·kg--1·day--1 for trial 2, and 15.9 g·kg--1·day-1 for trial 3. Muscle glycogen concentrations in the anterior (vastus lateralis and vastus intermedius) and posterior thighs (semimembranosus, semitendinosus, and biceps femoris) were measured using carbon-13 magnetic resonance spectroscopy. RESULTS: Muscle glycogen concentrations in both the anterior and posterior thighs increased in all trials, particularly in trial 3. Body mass also increased by 1.5 kg in trials 1 and 2 and by 1.8 kg in trial 3 before and after the trials. The participant felt satiated throughout the day and experienced stomach discomfort during trial 3. CONCLUSION: We found that a 2-day very-high-carbohydrate diet and tapering of training could further increase the muscle glycogen concentration in athletes. However, we speculated that 15.9 g·kg--1·day--1 carbohy.

Total daily energy expenditure has declined over the past three decades due to declining basal expenditure, not reduced activity expenditure.

Obesity is caused by a prolonged positive energy balance1,2. Whether reduced energy expenditure stemming from reduced activity levels contributes is debated3,4. Here we show that in both sexes, total energy expenditure (TEE) adjusted for body composition and age declined since the late 1980s, while adjusted activity energy expenditure increased over time. We use the International Atomic Energy Agency Doubly Labelled Water database on energy expenditure of adults in the United States and Europe (n = 4,799) to explore patterns in total (TEE: n = 4,799), basal (BEE: n = 1,432) and physical activity energy expenditure (n = 1,432) over time. In males, adjusted BEE decreased significantly, but in females this did not reach significance. A larger dataset of basal metabolic rate (equivalent to BEE) measurements of 9,912 adults across 163 studies spanning 100 years replicates the decline in BEE in both sexes. We conclude that increasing obesity in the United States/Europe has probably not been fuelled by reduced physical activity leading to lowered TEE. We identify here a decline in adjusted BEE as a previously unrecognized factor.

Skeletal muscle mass can be estimated by creatine (methyl-d3) dilution and is correlated with fat-free mass in active young males.

BACKGROUND: Assessing whole-body skeletal muscle mass (SMM) and fat-free mass (FFM) is essential for the adequate nutritional management and training evaluation of athletes and trained individuals. This study aimed to determine the relationship between SMM assessed using the creatine (methyl-d3) dilution (D3-creatine) method and SMM estimated by whole-body magnetic resonance imaging (MRI) in healthy young men undergoing exercise training. Additionally, we examined the association between FFM measured using the four-component (4C) method (FFM4C) and the total body protein value estimated using 4C (TBpro4C). METHODS AND RESULTS: We analyzed the data of 29 males (mean age, 19.9 ± 1.8 years) who exercised regularly. SMM measurements were obtained using the D3-creatine method (SMMD3-creatine) and MRI (SMMMRI). The SMMD3-creatine adjusted to 4.3 g/SMM kg was significantly higher than SMMMRI (p < 0.01). The fit of the creatine pool size compared with SMMMRI was 5.0 g/SMMMRI kg. SMMMRI was significantly correlated with both SMMD3-creatine adjusted to 4.3 g/kg and 5.1 g/kg. TBpro4C was significantly lower than SMMMRI (p < 0.01). Contrastingly, FFM4C was significantly higher than SMMMRI (p < 0.01). CONCLUSIONS: SMMD3-creatine adjusted to 4.3 g/SMM kg-a previously reported value-may differ for athletes and active young males. We believe that a value of 5.0-5.1 g/SMM kg better estimates the total muscle mass in this population. Traditional FFM estimation highly correlates with SMMMRI in well-trained young males, and the relationships appear strong enough for total body protein or SMM to be estimated through the FFM value.

Variation in human water turnover associated with environmental and lifestyle factors.

Water is essential for survival, but one in three individuals worldwide (2.2 billion people) lacks access to safe drinking water. Water intake requirements largely reflect water turnover (WT), the water used by the body each day. We investigated the determinants of human WT in 5604 people from the ages of 8 days to 96 years from 23 countries using isotope-tracking (2H) methods. Age, body size, and composition were significantly associated with WT, as were physical activity, athletic status, pregnancy, socioeconomic status, and environmental characteristics (latitude, altitude, air temperature, and humidity). People who lived in countries with a low human development index (HDI) had higher WT than people in high-HDI countries. On the basis of this extensive dataset, we provide equations to predict human WT in relation to anthropometric, economic, and environmental factors.

Human total, basal and activity energy expenditures are independent of ambient environmental temperature.

Lower ambient temperature (Ta) requires greater energy expenditure to sustain body temperature. However, effects of Ta on human energetics may be buffered by environmental modification and behavioral compensation. We used the IAEA DLW database for adults in the USA (n = 3213) to determine the effect of Ta (-10 to +30°C) on TEE, basal (BEE) and activity energy expenditure (AEE) and physical activity level (PAL). There were no significant relationships (p > 0.05) between maximum, minimum and average Ta and TEE, BEE, AEE and PAL. After adjustment for fat-free mass, fat mass and age, statistically significant (p < 0.01) relationships between TEE, BEE and Ta emerged in females but the effect sizes were not biologically meaningful. Temperatures inside buildings are regulated at 18-25°C independent of latitude. Hence, adults in the US modify their environments to keep TEE constant across a wide range of external ambient temperatures.

Relationship between Measured Aerobic Capacity and Total Energy Expenditure Obtained by the Doubly Labeled Water Method in Community-Dwelling, Healthy Adults Aged 81-94 Years.

The doubly labeled water method is a gold-standard method for the measurement of total energy expenditure in daily life. We aimed to identify the relationship between measured aerobic capacity and total energy expenditure, activity energy expenditure, or physical activity level using the doubly labeled water method in adults of advanced old age. A total of 12 physically independent older adults (10 men and 2 women), aged 81-94 years, participated in this study. The aerobic capacity was evaluated according to the lactate threshold. Total energy expenditure under free-living conditions was assessed using the doubly labeled water method, and self-reported physical activity was obtained using the Japanese version of the International Physical Activity Questionnaire. The lactate threshold was significantly positively correlated with total energy expenditure, activity energy expenditure, and physical activity level after adjusting for age and sex. We found that the aerobic capacity of the lactate threshold was positively and independently correlated with total energy expenditure, activity energy expenditure, or physical activity level. The present results suggest that maintaining aerobic capacity is an important factor in preventing frailty, although further research is required.

Food Quotient Assessments Using One-Week Dietary Records and Food Frequency Questionnaires of Young Japanese Runners.

The food quotient (FQ), which is the rate of macronutrient composition calculated from daily meals, can equal the respiratory quotient over a long term. The FQ is needed to estimate the total energy expenditure (TEE) in doubly labeled water studies. Usually, dietary records (DR) are used for dietary assessment in clinical nutritional studies; however, the DR method's disadvantage is that it takes time to calculate the results. In comparison, the food frequency questionnaires (FFQ) method is a simple and quick way to calculate results. This study aimed to assess the FQ in Japanese runners, and to compare the two dietary assessment methods, DR and FFQ, to examine whether FFQ is useful in calculating the FQ in healthy young adults and runner. The study consisted of 27 runners and 22 healthy young adults. The participants recorded and took pictures all their meals for 1 wk and provided the FFQ for the same week. The FQ was calculated using the proportions of proteins, fats, carbohydrates, and alcohol. There were no significant differences between the FQs of the runners 0.867 (male: 0.873, female: 0.863) and the healthy young adults 0.871 (male: 0.875, female: 0.867) according to the DR methods. There were no differences in the FQs between DR and FFQ methods for all groups. A significant correlation between the FQs (r=0.502, p<0.01), estimated using the DR, and the FQs estimated using the FFQ was observed. These results suggest that use of the FFQ method can provide comparable data for runners and healthy young adults.

Total energy expenditure is repeatable in adults but not associated with short-term changes in body composition.

Low total energy expenditure (TEE, MJ/d) has been a hypothesized risk factor for weight gain, but repeatability of TEE, a critical variable in longitudinal studies of energy balance, is understudied. We examine repeated doubly labeled water (DLW) measurements of TEE in 348 adults and 47 children from the IAEA DLW Database (mean ± SD time interval: 1.9 ± 2.9 y) to assess repeatability of TEE, and to examine if TEE adjusted for age, sex, fat-free mass, and fat mass is associated with changes in weight or body composition. Here, we report that repeatability of TEE is high for adults, but not children. Bivariate Bayesian mixed models show no among or within-individual correlation between body composition (fat mass or percentage) and unadjusted TEE in adults. For adults aged 20-60 y (N = 267; time interval: 7.4 ± 12.2 weeks), increases in adjusted TEE are associated with weight gain but not with changes in body composition; results are similar for subjects with intervals >4 weeks (N = 53; 29.1 ± 12.8 weeks). This suggests low TEE is not a risk factor for, and high TEE is not protective against, weight or body fat gain over the time intervals tested.

Comparative evaluation of obesity-related parameters in junior sumo wrestlers and children with obesity.

PURPOSE: Exercise is a key factor in preventing obesity and metabolic syndrome. Sumo wrestlers increase their body size from childhood for athletic advantage; however, the risk of metabolic syndrome in junior sumo wrestlers is undetermined. Preventive measures against pediatric obesity should be initiated during childhood to prevent obesity in adulthood, considering its high global incidence. We comparatively evaluated the risk factors for metabolic syndrome in junior sumo wrestlers and children with obesity. METHODS: We enrolled 70 male children (age 9-17 years [sumo group, n = 14] and 9-14 years [other sports and non-exercise groups, n = 28 each]) and evaluated their anthropometric parameters (height, weight, body mass index z-score, obesity rate, waist circumference, waist to height ratio) and hematological parameters (total, low-density, high-density, and non-high-density lipoprotein-cholesterol; triglycerides; plasma glucose, and glycated hemoglobin levels). RESULTS: The BMI z-score, obesity rate, waist circumference (p < 0.05, along with the non-exercise group), and systolic blood pressure were significantly higher and the high-density cholesterol level was lower in the sumo group than in the other sports group (p < 0.05). The waist to height ratio was significantly higher in the non-exercise group than in the other sports group (p < 0.05). No significant difference was found in other blood lipid, plasma glucose (significantly lower level than the reference range in the sumo group, p < 0.05), and glycated hemoglobin (within the reference range in all groups) levels among the three groups. CONCLUSION: Junior sumo wrestlers had a larger body size and higher blood pressure than children with obesity who exercised regularly. This provides direction for future research into targeted preventive interventions against metabolic syndrome for junior sumo wrestlers with large body size.

Association between Water and Energy Requirements with Physical Activity and Fat-Free Mass in Preschool Children in Japan.

Water and energy are essential for the human body. The doubly labeled water (DLW) method measures water turnover (WT) and total energy expenditure (TEE), which serves as a benchmark for the adequate intake (AI) of water and estimated energy requirements (EER). The objective of the current study was to examine the association of WT and TEE with physical activity and body composition in Japanese preschool children. We included 41 preschool children (22 girls, 19 boys) aged 3-6 in this study. WT, TEE, and fat-free mass (FFM) were obtained using DLW. Physical activity was measured using a triaxial accelerometer and categorized as light (LPA; 1.5-2.9 Metabolic equivalents, METs) and of moderate-to-vigorous intensity (MVPA; ≥3.0 METs). Exercise duration (Ex) was defined as ≥4.0 METs of physical activity. WT and TEE moderately positively correlated with Ex, but not with LPA. WT moderately positively correlated with BW and FFM while TEE strongly. We established predictive equations for WT and TEE using body weight (BW), FFM, step count, and Ex to guide the AI of water and EER in Japanese preschool children. We found that FFM and step count are the determinants of TEE, and that BW and Ex are the determinants of WT in preschool children.

Metabolic flexibility during sleep.

Known as metabolic flexibility, oxidized substrate is selected in response to changes in the nutritional state. Sleep imposes an extended duration of fasting, and oxidized substrates during sleep were assumed to progressively shift from carbohydrate to fat, thereby gradually decreasing the respiratory quotient (RQ). Contrary to this assumption, whole-room indirect calorimetry with improved time resolution revealed that RQ re-ascended prior to awakening, and nadir of RQ in non-obese young adults occurred earlier in women than men after bedtime. The transient decrease in RQ during sleep was blunted in metabolically inflexible men with smaller amplitude of diurnal rhythm in RQ. Similarly, the effect of 10 years difference in age on RQ became significant during sleep; the decrease in RQ during sleep was blunted in older subjects. Inter-individual difference in RQ become apparent during sleep, and it might serve as a window to gain insight into the early-stage pathogenesis of metabolic inflexibility.