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.

Individually optimized estimation of energy expenditure in rescue workers using a tri-axial accelerometer and heart rate monitor.

Objectives: This study aimed to provide an improved energy expenditure estimation for heavy-load physical labor using accelerometer data and heart rate (HR) measured by wearables and to support food preparation and supply management for disaster relief and rescue operations as an expedition team. Methods: To achieve an individually optimized estimation for energy expenditure, a model equation parameter was determined based on the measurements of physical activity and HR during simulated rescue operations. The metabolic equivalent of task (MET), which was measured by using a tri-axial accelerometer and individual HR, was used, where two (minimum and maximum) or three (minimum, intermediate, and maximum) representative reference points were selected for each individual model fitting. In demonstrating the applicability of our approach in a realistic situation, accelerometer-based METs and HR of 30 males were measured using the tri-axial accelerometer and wearable HR during simulated rescue operations over 2 days. Results: Data sets of 27 rescue operations (age:34.2 ± 7.5 years; body mass index (BMI):22.9 ± 1.5 kg/m2) were used for the energy expenditure estimation after excluding three rescue workers due to their activity type and insufficient HR measurement. Using the combined approach with a tri-axial accelerometer and HR, the total energy expenditure increased by 143% for two points and 133% for three points, compared with the estimated total energy expenditure using only the accelerometer-based method. Conclusion: The use of wearables provided a reasonable estimation of energy expenditure for physical workers with heavy equipment. The application of our approach to disaster relief and rescue operations can provide important insights into nutrition and healthcare management.

Blood Glucose Levels during Decathlon Competition: An Observational Study in Timing of Intake and Competing Time.

During a men's decathlon, a combined event conducted over two consecutive days, fluctuations in blood glucose were measured using flash glucose monitoring. Because decathletes repeatedly intake and exercise, high and low blood glucose levels are observed, but the actual conditions have not yet been clarified. Low blood glucose levels (<80 mg/dL) were observed in nine athletes, while high blood glucose levels (>139 mg/dL) were observed in all athletes at least once during the competition days. Furthermore, low blood glucose levels were observed in nine athletes at least once during and after intake ("intake" refers to consuming energy-containing food and beverages). Additionally, high blood glucose levels were observed in nine athletes at least once during and after intake. Five athletes had low blood glucose during competing time. It was suggested that even if they had eaten a meal just prior to the competition, their intake was likely insufficient for their energy expenditure. A significant positive correlation was found between the mean blood glucose level and the number of intakes on competition days. It is believed that meals may have had a strong influence on blood glucose, even on competition days with a high frequency of eating and exercise for the decathlon.

Running exercise and food restriction affect bone chemical properties in young female rats.

PURPOSE: To investigate the effects of a combination of running and food restriction on the chemical properties of the bone in young female rats using Raman spectroscopy. Furthermore, we investigated whether the chemical property parameters correlated with the bone-breaking strength. METHODS: Female Sprague-Dawley rats (7 weeks old) were randomly divided into four groups: sedentary and ad libitum feeding (SED, n = 8), voluntary running exercise and ad libitum feeding (EX, n = 8), sedentary and 30% food-restricted (SED-FR, n = 8), and voluntary running exercise and 30% food-restricted (EXFR, n = 8). The experiment was conducted for a period of 12 weeks. Four parameters measured by Raman spectroscopy were used to evaluate the bone chemical quality. RESULTS: Exercise and restriction had significant interactions on the mineral to matrix ratio. The mineral- to-matrix ratio in the SED-FR group was significantly higher than that in the SED group and significantly lower in the EX-FR group than that in the SED-FR group. Running exercise had significant effects on increasing the crystallinity and carbonate-to-phosphate ratio. In the ad libitum intake condition, there were significant positive correlations between breaking energy and crystallinity (r = 0.593) and between breaking energy and carbonate-to-phosphate ratio (r = 0.854). CONCLUSION: Our findings show that running exercise and food restriction, alone or in combination, affect the chemical properties of bone. Furthermore, under ad libitum intake conditions, positive correlations were found between the breaking energy and crystallinity, or carbonate-to-phosphate ratio.

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.

Association between Dietary Consumption of Meals Combining the Five Food Groups and Stage of Change in the Fifth and Sixth Elementary and Junior High School-Aged Children in Sports Clubs: A Cross-Sectional Research at Soccer Clubs.

This study examined the relationship between dietary intake and stage of change for "combining the five food groups" (grains, fish and meat, vegetables, milk, and fruits) and examined characteristics of dietary intake by stage of change among fifth and sixth graders in elementary and junior high school in sports clubs. The 395 children who completed the self-reported dietary consumption form and questionnaire on stage of change for combining the five food groups were analyzed. Logistic regression analysis was conducted to analyze the relationship between intake of the combined five food groups and stage of change, with frequency of the five meals as dependent variable and stage of change as independent variable. Compared to the precontemplation stage, action (A) and maintenance stages (M) were associated with a higher frequency of the number of meals combining the five food groups (A, stage adjusted odds ratio [AOR]: 5.11, 95% confidence interval (CI): 1.50-17.36, p=0.009; M, AOR: 3.84, 95%CI: 1.58-9.33, p=0.003). In breakfast, the number of and each of combining the five food groups meal, and in dinner, the number of combining the five food groups meal, vegetable dishes and fruits were significantly higher in the A and M than in the pre-action stages. These findings suggest that the number of times meals combining the five food groups are consumed was associated with stage of change while breakfast and dinner showed differences in meal consumption between stages in the fifth and sixth grades elementary and junior high school students belonging to sports clubs.

Energy Expenditure of Disaster Relief Operations Estimated Using a Tri-Axial Accelerometer and a Wearable Heart Rate Monitor.

The management of nutrition, food, and health for disaster relief personnel is one of the crucial aspects for carrying out effective rescue activities during large-scale natural disasters, such as a big earthquake, flooding, and landslide following heavy rainfall or man-made disasters, such as widespread fire in industrial areas. Rescue workers, such as fire fighters and rescue teams who work on the disaster relief operations, have to work long, hard, and irregular hours that require energy (both intake and expenditure), with especially altered eating patterns. Reliable estimates of the energy expenditure (TEE) for such disaster relief operations have not been fully established. Here, we propose to clarify the energy expenditure for each type of large-scale disaster activity conducted by fire fighters. Thirty fire fighters (survey participants in this research) who participated in the simulation training of large-scale disaster activities wore tri-axial accelerometers and heart rate monitors during training; and, post-training, 28 fire fighters submitted complete activity record tables. An estimation formula combining tri-axial accelerometer and heart rate monitor data was used. Additionally, energy expenditure per hour (excluding resting energy expenditure: REE) (per average body weight of participants) was calculated for 10 types of large-scale disaster response activities. We propose utilization of these data as a reference value for examining the TEE of firefighting and rescue operations in future large-scale disasters.

Enzymatically modified isoquercitrin in soy protein temporarily enhanced the plasma amino-acid concentrations, antioxidant index, and plasma hormone levels: a randomized, double-blind cross-over trial.

This study investigated the effects of a dietary protein supplement containing enzymatically modified isoquercitrin (EMIQ) on plasma amino-acid levels in healthy people. A randomized double-blind cross-over trial (UMIN000044791) was conducted with a sample of nine healthy individuals. These participants ingested soy protein with or without 42 mg EMIQ for 7 days after performing mild exercise. Plasma amino-acid levels were measured before ingestion and at 15, 30, 45, 60, 90, 120, 180, and 240 min after ingestion on the last day. The concentrations of total amino acids at 0 and 120 min and easily oxidized amino acids at 120 min were significantly higher in the plasma of individuals who consumed 42 mg EMIQ. Oxidative stress levels were lower and plasma testosterone levels were higher in participants who ingested soy protein with 42 mg EMIQ than in those who did not. These results suggest that daily ingestion of soy protein with 42 mg EMIQ can be useful for effective protein absorption.

Dietary nitrate supplementation increases nitrate and nitrite concentrations in human skin interstitial fluid.

Acute dietary nitrate (NO3-) supplementation can increase [NO3-], but not nitrite ([NO2-]), in human skeletal muscle, though its effect on [NO3-] and [NO2-] in skin remains unknown. In an independent group design, 11 young adults ingested 140 mL of NO3--rich beetroot juice (BR; 9.6 mmol NO3-), and 6 young adults ingested 140 mL of a NO3--depleted placebo (PL). Skin dialysate, acquired through intradermal microdialysis, and venous blood samples were collected at baseline and every hour post-ingestion up to 4 h to assess dialysate and plasma [NO3-] and [NO2-]. The relative recovery rate of NO3- and NO2- through the microdialysis probe (73.1% and 62.8%), determined in a separate experiment, was used to estimate skin interstitial [NO3-] and [NO2-]. Baseline [NO3-] was lower, whereas baseline [NO2-] was higher in the skin interstitial fluid relative to plasma (both P < 0.001). Acute BR ingestion increased [NO3-] and [NO2-] in the skin interstitial fluid and plasma (all P < 0.001), with the magnitude being smaller in the skin interstitial fluid (e.g., 183 ± 54 vs. 491 ± 62 µM for Δ[NO3-] from baseline and 155 ± 190 vs. 217 ± 204 nM for Δ[NO2-] from baseline at 3 h post BR ingestion, both P ≤ 0.037). However, due to the aforementioned baseline differences, skin interstitial fluid [NO2-] post BR ingestion was higher, whereas [NO3-] was lower relative to plasma (all P < 0.001). These findings extend our understanding of NO3- and NO2- distribution at rest and indicate that acute BR supplementation increases [NO3-] and [NO2-] in human skin interstitial fluid.

Meal Timing and Sleeping Energy Metabolism.

There is a physiological link between sleep and eating. Insufficient sleep is a risk factor for overeating and excess body weight gain, and molecules such as orexin and insulin play a role in the control of sleep and energy intake. The effects of dietary timing on sleep and energy metabolism were examined in this review. First, we examined sleep energy metabolism and sleep quality under time-restricted eating, including skipping breakfast or dinner. Second, the mechanisms, benefits, and translational potential of the effects of time-restricted diets on sleep were discussed. Time-restricted eating under controlled conditions, in which daily caloric intake was kept constant, affected the time course of energy metabolism but did not affect total energy expenditure over 24 h. In free-living conditions, time-restricted eating for extended durations (4-16 weeks) decreased energy intake and body weight, and the effects of early time-restricted eating were greater than that of midday time-restricted eating. Although assessment of sleep by polysomnographic recording remains to be performed, no negative effects on the subjective quality of sleep have been observed.

Female athlete triad affects rat intestinal morphology and sucrase-isomaltase expression.

Female athletes follow a strict diet and perform rigorous exercise to boost their performance, which induces health issues called the female athlete triad (FAT), defined as the combination of disordered eating, amenorrhoea and low bone mineral density. It is known to have a significant effect on bones. However, its effects on the small intestine, which is responsible for nutrient uptake into the body, remain unclear. In this study, we created an animal model of FAT to examine its effects on digestive and absorptive molecules in the small intestine. Thirty 5-week-old female Sprague-Dawley (sd) rats with an initial body weight of about 147 g were divided into control (Con, n = 7), exercise (Ex, n = 7), food restriction (FR, n = 8) and exercise plus food restriction (FAT, n = 8) groups. The rats were subjected to 4 weeks of wheel running (Ex, FAT) and 50-40 % food restriction (FR, FAT) to examine the effects on bone and typical digestive enzymes and transporters in the jejunum. Two-way ANOVA and the Kruskal-Wallis test were used for statistical analysis of normal and non-normal data, respectively. Four weeks of exercise and food restriction decreased bone weight (vs. other group P < 0·01) and bone breaking power (vs. other group P < 0·01). Villus height decreased in the jejunum (vs. other group P < 0·01), but the expression of typical macronutrients digestive enzyme and absorptive molecules remained unchanged. In contrast, sucrase-isomaltase gene (v. Ex P = 0·02) and protein expression were increased (vs. other group P < 0·05). The study findings show that FAT affects sucrase-isomaltase without histone methylation changes.

Self-Efficacy of Parents of Boys in Sports Clubs on Meal Preparation and Boys' Dietary Intake: A Cross-Sectional Study of Soccer Clubs.

This study examined the relationship between parents' self-efficacy for preparing meals combining the five food groups (grains, fish and meat, vegetables, milk, and fruits) and the dietary intake of their children who were elementary and junior high school students belonging to a sports club. A total of 365 children completed a self-reported dietary intake form, and their parents completed a questionnaire on self-efficacy for preparing meals combining the five food groups. Logistic regression analysis was conducted to assess the relationship between the children's intake of the combined five food groups and parents' self-efficacy score, with frequency of meals combining the five food groups as the dependent variable and the self-efficacy score as the independent variable. In a multivariate logistic regression analysis that was higher self-efficacy scores were associated with a higher frequency of meals that contained all five food groups, with an odds ratio of 1.06 (95% confidence interval: 1.00-1.12; p=0.036). Significant positive correlations were also found between parents' self-efficacy and the number of times children consumed four food types (fish and meat, vegetables, milk, and fruits) at breakfast and three food types (grains, milk, and fruits) at dinner. These findings suggest that parents' self-efficacy for preparing meals combining the five food groups was associated with the number of meals with all five food groups consumed by their children, who were fifth and sixth graders in elementary and junior high school and belonged to sports clubs.

Does earlier acquisition of motor competence promote pubertal physical activity in Japanese elementary school children: A 4-year follow-up study.

This 4-year follow-up study investigated which profile of motor competence (MC) in early childhood more strongly correlated with moderate-to-vigorous physical activity (MVPA) in early pubescence. A total of 247 first-grade children (152 boys) aged 6 to 7 years old participated in the baseline measurement. MVPA was measured using an accelerometer annually until the fifth grade. Body fat percentage was assessed using dual-energy X-ray absorptiometry at baseline. MC included fundamental movement skills (FMS) and motor performance, which were assessed in terms of locomotor and object control. FMS was assessed by the Test of Gross Motor Development-2, while motor performance (locomotor: run, hop, jump, and side-step, object control: throw, kick, and hand dribble) was assessed by Japanese Physical Fitness and Motor Abilities Test at baseline. Multiple regression analysis showed that locomotor and object control performance were significant predictors of MVPA in later grades in boys but not in girls. These associations between locomotor performance and MVPA mainly remained significant after controlling for body fat and MVPA at baseline. FMS in both genders was not a significant predictor of MVPA in early pubescence. This study suggests that appropriate strategies for increasing MVPA from prepubescence to early pubescence may differ between boys and girls.

Soy protein intake increased bone mineral density under nonenergy-deficiency conditions but decreased it under energy-deficiency conditions in young female rats.

Many young individuals attempt to lose too much weight because of a false body image, which induces low bone mineral density (BMD) resulting from energy restriction. In addition, a decrease in estrogen has been observed along with the decrease in BMD. Estrogen is responsible for maintaining bone mass, and soybeans contain high levels of isoflavones, which have estrogen-like effects. Thus, we hypothesized that soy protein prevents low BMD caused by energy deficiency in young female rats. The purpose of this study was to examine the effect of soy protein intake on bone loss by energy deficiency in young female rats. Female Sprague-Dawley rats (6 weeks old) were randomly divided into the following 4 experimental groups: ad libitum feeding and casein diet (AL-Cas); ad libitum feeding and soy diet (AL-Soy); 40% energy restriction and casein diet (ER-Cas); and 40% energy restriction and soy diet (ER-Soy). The experimental period was 10.5 weeks. The AL-soy group had significantly higher BMD of the femur than the AL-Cas group (AL-Cas = 156 ± 5 mg/cm2, AL-Soy = 165 ± 7 mg/cm2; P < .05). Meanwhile, the ER-Soy group had significantly lower BMD of the tibia, femur, and lumbar spine than the ER-Cas group (ER-Cas = 147 ± 7 mg/cm2, ER-Soy = 133 ± 10 mg/cm2; P < .01). These results show that compared with ad libitum control groups, soy protein resulted in higher BMD under nonenergy deficiency, but under energy-deficiency conditions, it resulted in lower BMD.

Female Athlete Triad and Male Athlete Triad Syndrome Induced by Low Energy Availability: An Animal Model.

Energy availability (EA) is defined the difference in energy intake and exercise energy expenditure. Reduction of EA (i.e. Low energy availability, LEA) often causes abnormalities of reproduction system and drastic bone loss in some female athletes, the phenomenon is called as female athlete triad. More than ever before, it is considered a serious problem, the reason of these are (1) the syndrome occurred in female athletes but also male athletes, (2) LEA is leads to dysfunction of various organs other than reproductive system (Relative energy deficiency in sport, RED-S). On the other hand, we have focused on this syndrome and have proposed novel insights into the physiological effects of LEA on bone and solutions through nutritional treatment by recreating it in animal models. In this review, we will summarize the epidemiological and physiological perspectives of these diseases from historical background to recent findings, and introduce the usefulness of using animal models to explore mechanisms and treatments.

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.

Association Between Age of Achieving Gross Motor Development Milestones During Infancy and Body Fat Percentage at 6 to 7 Years of Age.

OBJECTIVES: The later achievement of gross motor milestones during infancy is associated with adiposity in early childhood. However, the associations between gross motor development and adiposity after entering primary school are unclear. This study examined the associations between the ages at which six gross motor milestones were achieved and adiposity during early school years. METHODS: This retrospective study was conducted in 2012 and 2013. Data were collected from 225 first-grade primary school children (mean age, 6.9 years; 39% girls). Adiposity was assessed using dual-energy X-ray absorptiometry and expressed as body fat percentage. Data describing the ages of achieving six gross motor milestones (holding head up, sitting, crawling, standing supported, walking supported, and independent walking) were obtained from the Maternal and Child Health Handbooks. RESULTS: Mean body fat percentage was 21.7%. Multiple linear regression analyses revealed that later ages of achieving crawling (p < .001 [95% confidence interval: 0.33-1.16]), standing supported (p < .001 [95% confidence interval: 0.64-1.65]), and walking supported [p = .013 (95% confidence interval: 0.13-1.07)] were associated with increased fat. However, the ages of achieving holding head up (p = .053), sitting (p = .175), and independent walking (p = .736) were not statistically significant. CONCLUSIONS: Achieving crawling, standing supported, and walking supported later predict increased body fat when aged 6-7 years. The practice of observing gross motor milestone achievements may allow early targeted interventions to optimize body composition before beginning school and thereby, potentially prevent childhood obesity.

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.

Estimating Total Energy Expenditure for Fire-Fighters during Large Scale Disaster Response Training Using a Tri-Axial Accelerometer.

The present study was conducted to estimate total energy expenditure (TEE) of fire-fighters using tri axial-accelerometers in conjunction with an activity log survey on a large number of subjects undergoing training mimicking a large-scale disaster. Subjects were 240 fire-fighters participating in a two-day fire-fighting training dedicated to large-scale natural disasters. Data was analyzed by job type of activity group and the job rank, and by comparing the average. The average TEE of the total survey training period is about 3619 (±499) kcal, which is the same value of expenditure for professional athletes during the soccer game season. From the activity group, the rescue and other teams consumed significantly more energy than the fire and Emergency Medical Team (EMS) teams. From the job rank, Fire Captain (conducting position) consumed significantly lower energy than the Fire Lieutenant and Fire Sergeant. Furthermore, it was found that a middle position rank consumed the most energy. This research supports a need to reconsider the current rescue food (and protocols) to supplement the energy expenditure of fire-fighters. In addition, since there was a significant difference between the job type and the job rank, it is necessary to examine the energy amount and shape suitable for each.

Effect of ginger extract ingestion on skeletal muscle glycogen contents and endurance exercise in male rats.

PURPOSE: Skeletal muscle glycogen is a determinant of endurance capacity for some athletes. Ginger is well known to possess nutritional effects, such as anti-diabetic effects. We hypothesized that ginger extract (GE) ingestion increases skeletal muscle glycogen by enhancing fat oxidation. Thus, we investigated the effect of GE ingestion on exercise capacity, skeletal muscle glycogen, and certain blood metabolites in exercised rats. METHODS: First, we evaluated the influence of GE ingestion on body weight and elevation of exercise performance in rats fed with different volumes of GE. Next, we measured the skeletal muscle glycogen content and free fatty acid (FFA) levels in GE-fed rats. Finally, we demonstrated that GE ingestion contributes to endurance capacity during intermittent exercise to exhaustion. RESULTS: We confirmed that GE ingestion increased exercise performance (p<0.05) and elevated the skeletal muscle glycogen content compared to the non- GE-fed (CE, control exercise) group before exercise (Soleus: p<0.01, Plantaris: p<0.01, Gastrocnemius: p<0.05). Blood FFA levels in the GE group were significantly higher than those in the CE group after exercise (p<0.05). Moreover, we demonstrated that exercise capacity was maintained in the CE group during intermittent exercise (p<0.05). CONCLUSION: These findings indicate that GE ingestion increases skeletal muscle glycogen content and exercise performance through the upregulation of fat oxidation.