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.

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.

The incidence of Jarisch-Herxheimer reactions and associated risk factors in pregnant women and nonpregnant women: A retrospective chart review at a university hospital in Japan.

AIMS: Jarisch-Herxheimer reactions (JHR) is a transient adverse event that occurs during initial antimicrobial treatment for syphilis patients, and is known to develop uterine contractions and fetal distress in pregnant women complicated with syphilis. The aim of this study is to identify risk factors for JHR in patients with syphilis, and to clarify whether pregnancy status is a risk factor for JHR, and to describe the characteristics of pregnant women who develop JHR. METHODS: This was a retrospective chart review in a singleton university hospital in Japan. We collected data of syphilis patients who were diagnosed and treated at department of obstetrics and gynecology, dermatology between January 2010 and May 2022. There were no validated diagnostic criteria for JHR, we defined JHR as one or more of the following in addition to raised body temperature (≧38.0°C) within 24 h of initial antibiotic treatment: headache, chills, myalgias, tachycardia (≧110 bpm), new rash. RESULTS: There were 30 syphilis patients. Of whom nine (30%) were pregnant women and all their neonates were not diagnosed with congenital syphilis. Five patients (17%) developed JHR at the time of initial treatment (JHR group, n = 5). There was no difference between JHR group and non-JHR group (n = 25) in pregnancy status. Secondary syphilis was an only significant risk factor for JHR. Two pregnant women with JHR were both treated for secondary syphilis in the third trimester of pregnancy. CONCLUSION: Pregnancy status was not a risk factor for JHR in syphilis patients. Further research is needed.

Relationship between placental hemodynamics and placental histological analysis in third trimester.

AIM: To investigate whether vascularization index (VI), flow index (FI), and vascularization flow index (VFI) correlate with the pathological structure of the placenta and whether there were any differences in VI, FI, VFI, and placental pathological structure between the normal and preeclampsia (PE) groups. METHODS: Fifty-five pregnant women (normal group, n = 27; PE group, n = 28) underwent VI, FI, and VFI at four locations in the placenta during the second and third trimesters. Two hematoxylin and eosin (HE)-stained specimens of the postpartum placenta were prepared. We randomly selected two of these locations and used ImageJ, an open-source image package, to quantify intervillous blood vessels (IBV), intervillous spaces (IS), and intervillous blood vessels + intervillous spaces (IBV + IS) per unit placenta and analyzed their correlation with VI, FI, and VFI. RESULTS: There was no positive correlation between VI, FI, VFI, IBV, IS, and IBV + IS. There were no significant differences in VI, FI, and VFI between the normal and PE groups; however, there were significant differences in IBV, IS, and IBV + IS in the PE group compared to those in the normal group. CONCLUSIONS: Placental hemodynamics measured by VI, FI, and VFI were not positively correlated with placental morphology in the third trimester. There were no differences in the VI, FI, and VFI in the third trimester between the normal and PE groups, suggesting that these may reflect placental circulatory insufficiency.

Acute Myositis in a Pregnant Woman Complicated With COVID-19 and Hyperemesis Gravidarum: A Case Report.

Myalgia is the most frequently reported neuromuscular symptom in COVID-19 patients, with a frequency of around 20% in pregnant women. Acute myositis due to COVID-19 is severe and requires medical intervention. There have been some reports of acute myositis due to COVID-19, mostly in elderly men, but rarely in pregnant women. Here we report a case of a pregnant woman who was diagnosed with acute myositis following COVID-19 illness early in her pregnancy. She had been affected by morning sickness since the 6th week of gestation and was diagnosed with COVID-19 at the 12th week. Muscle pain appeared in her limbs 5 days after the diagnosis of COVID-19, with a predominance of pain in the lower limbs, and her gait gradually became unstable. We concluded that it was acute myositis complicated by COVID-19 and hypokalemia, but we could not determine whether hypokalemia or COVID-19 or both were the cause of the muscle damage in this case. Pregnant women diagnosed with COVID-19 often complain of myalgia and fatigue, and when a pregnant woman's symptoms are severe we should keep in mind that they may be suffering from muscle damage that needs medical intervention.

Validation of skeletal muscle mass estimation equations in active young adults: A preliminary study.

We analyzed the validity of the estimation equations for skeletal muscle mass (SMM) using mass of appendicular lean soft tissue (ALST), evaluated by dual-energy X-ray absorptiometry (DXA), in healthy young males undergoing training, and compared it with the results obtained using whole-body magnetic resonance imaging (MRI). We hypothesized that a novel variable, that is, trunk and trunk-to-appendicular ratio of lean soft tissues (trunk/ALST), would be useful in reducing estimation errors in athletes or physically active participants. We analyzed the data of 30 participants (mean age 19.9 ± 1.8 years). SMM was measured using whole-body MRI, while mass of trunk and ALST was assessed using DXA. Three previously utilized estimation equations were retrieved from the literature and used for comparison. The estimated SMM values using previous equations highly correlated with measured SMM, which was determined by MRI, but the mean estimated SMM values were significantly lower than the measured-SMM values. Stepwise regression analysis revealed that mass of ALST, trunk/ALST ratio, and percent body fat were significant predictors of SMM and were incorporated as the new suggested variables. This equation accounted for 90.3% of the variance in SMM. While the previous equations' estimated SMM correlated with measured-SMM in participants with trunk/ALST ratios ≤1.05, they underestimated SMMs in those with trunk/ALST ratios >1.05. The present study confirms that the previously used equations underestimate the actual SMM, particularly in participants with high trunk/ALST ratios (>1.05). The current equation may be used in healthy and active young males, including athletes, as a preliminary tool.

The utility of shock index and heart rate in the management of postpartum blood loss in pregnant women complicated with hypertensive disorders in pregnancy.

BACKGROUND: Although the shock index (SI) (heart rate/systolic blood pressure) and heart rate (HR) are a helpful indicator in the management of postpartum blood loss, there are few reports of SI in pregnant women complicated with hypertensive disorders in pregnancy (HDP). The purpose of this study was to examine whether SI and HR would be a clinically helpful indicator, and to detect the cutoff value for judging abnormal obstetric bleeding. METHODS: This was a retrospective case-control study in 107 patients with HDP in a singleton tertiary perinatal medical facility. The values of postpartum highest SI (peak SI) and highest HR (peak HR), and the amount of bleeding until peak SI and peak HR were retrospectively examined and analyzed. We used the receiver operating characteristic analysis to assess the diagnostic value of peak SI and peak HR for judging abnormal obstetric bleeding. RESULTS: Peak SI and peak HR were significantly related to the amount of bleeding up to peak SI and up to peak HR. The cutoff values of peak SI with blood loss volumes above 500 ml, 1000 ml, and 1500 ml were 0.77, 0.76, and 0.99, respectively. The cutoff values of peak HR with blood loss volumes above 500 ml, 1000 ml, and 1500 ml were 97, 98, and 103, respectively. CONCLUSION: In cases of pregnant women complicated with HDP, both SI and HR were probably useful indicators in the management of postpartum blood loss. Further prospective trials are warranted to confirm these results.

Urinary N-Terminal Fragment of Titin Reflects Muscle Damage After a Soccer Match in Male Collegiate Soccer Players.

ABSTRACT: Tanabe, Y, Shimizu, K, Kondo, E, Yasumatsu, M, Nakamura, D, Sagayama, H, and Takahashi, H. Urinary N-terminal fragment of titin reflects muscle damage after a soccer match in male collegiate soccer players. J Strength Cond Res 35(2): 360-365, 2021-Previous studies have demonstrated that noninvasive urinary N-terminal fragment of titin (U-titin) concentration highly correlates with serum creatine kinase (CK) activity, a classic invasive muscle damage marker. This finding indicates that U-titin could be used to estimate muscle damage. However, these results were achieved using a laboratory-based eccentric exercise model. Therefore, it remains unclear whether U-titin is useful for evaluating muscle damage occurring in field sports events. As a result, we evaluated whether U-titin concentration closely relates to serum CK activity after a soccer match. Seventeen collegiate soccer players (age: 20 ± 1 year; height: 172 ± 6 cm; body mass: 65 ± 5 kg; Yo-Yo intermittent recovery test level 2, 1,135 ± 196 m) completed a test match (2 halves of 45 minutes separated by 15 minutes of normal half-time). U-titin concentration, serum CK activity, countermovement jump performance, and muscle soreness were assessed 2 hours before the match and 30 minutes, 24 hours, and 48 hours after the match. U-titin concentrations and CK activity similarly increased at 24 hours and returned to the baseline value at 48 hours after the match. Moreover, the percentage of changes in U-titin concentration from baseline after the match significantly and positively correlated with serum CK activity (r = 0.82, p < 0.05). These results suggest that the noninvasive marker U-titin can be used to assess muscle damage conditions in field sports events, such as soccer matches.

Evaluation of fat-free mass hydration in athletes and non-athletes.

PURPOSE: To evaluate the hydration of fat-free mass (FFM) in athletes and non-athletes. METHODS: We analyzed the data of 128 healthy young adults (athletes: 61 men, 36 women; non-athletes: 19 men, 12 women) using the two-component (2C), 3C and 4C models. Under-water weighing or air-displacement plethysmography and deuterium dilution methods were used for estimating body density and total body water, respectively. The bone mineral content (BMC) was determined using whole-body scans by dual-energy X-ray absorptiometry. RESULTS: There was no significant difference in FFM hydration between the athletes (men, 72.3 ± 1.3%; women, 71.8 ± 1.3%) and non-athletes (men, 72.1 ± 1.2%; women, 72.2% ± 1.0%) in the 3C model. The total mean FFM hydration (72.1% ± 1.3%) was similar to the corresponding value in the literature (~ 73%). The estimation error of the percentage fat by the 2C vs the 4C model was significantly and highly correlated with hydration (r = 0.96), BMC (r = - 0.70), and total body protein (r = - 0.86) in the 4C model FFM. CONCLUSION: Although FFM hydration was similar in athletes and non-athletes, it would be underestimated or overestimated when the 2C model is used for evaluation, and the biological FFM hydration value deviates from the 73% value inter-individually. Despite that this inter-individual variation in FFM hydration is low in terms of between-individual standard deviation (1.3%), the BMC and total body protein differ greatly in athletes, and when it affects FFM hydration, it may also affect the percentage fat measurement in the 2C model. Thus, FFM hydration would not be affected by FFM, percent body fat, or the athletic status.

The influence of outdoor thermal environment on young Japanese females.

The influence of short wave solar radiation appears to be strong outdoors in summer, and the influence of airflow appears to be strong outdoors in winter. The purpose of this paper was to clarify the influence of the outdoor environment on young Japanese females. This research shows the relationship between the physiological and psychological responses of humans and the enhanced conduction-corrected modified effective temperature (ETFe). Subjective experiments were conducted in an outdoor environment. Subjects were exposed to the thermal environment in a standing posture. Air temperature, humidity, air velocity, short wave solar radiation, long wave radiation, ground surface temperature, sky factor, and the green solid angle were measured. The temperatures of skin exposed to the atmosphere and in contact with the ground were measured. Thermal sensation and thermal comfort were measured by means of rating the whole-body thermal sensation (cold-hot) and the whole body thermal comfort (comfortable-uncomfortable) on a linear scale. Linear rating scales are given for the hot (100) and cold (0), and comfortable (100) and uncomfortable (0) directions only. Arbitrary values of 0 and 100 were assigned to each endpoint, the reported values read in, and the entire length converted into a numerical value with an arbitrary scale of 100 to give a linear rating scale. The ETFe considered to report a neither hot nor cold, thermally neutral sensation of 50 was 35.9 °C, with 32.3 °C and 42.9 °C, respectively, corresponding to the low and high temperature ends of the ETFe considered to report a neither comfortable nor uncomfortable comfort value of 50. The mean skin temperature considered to report a neither hot nor cold, thermally neutral sensation of 50 was 33.3 °C, with 31.0 °C and 34.3 °C, respectively, corresponding to the low and high temperature ends of the mean skin temperature considered to report a neither comfortable nor uncomfortable comfort value of 50. The acceptability raised the mean skin temperature even for thermal environment conditions in which ETFe was high.

The Energy Required to Synthesize Lean and Adipose Tissue in Rats.

Although the energy stored in lean tissue (LT) and adipose tissue (AT) is well known, the energy required to synthesize these tissues is less clear. While elucidating the energy required for AT synthesis may not be so important, the elucidation of the energy required for LT synthesis is important for individuals who aim to increase their skeletal muscle. Theoretically the energy at the point at which ΔLT/Δbody weight (BW) reaches 100% on a regression curve, which indicates the relationship between ΔLT/ΔBW and the energy used to accumulate body tissue, is considered to be the energy expended to synthesize LT. We therefore investigated the relationship using rats. Rats of different ages, and rats in exercised or sedentary states were used because their ΔLT/ΔBW was expected to be different. ΔLT/ΔBW was higher in the 4-wk-old group than in the 8-wk-old group and higher in the exercise group than in the sedentary group. We found a positive correlation between ΔLT/ΔBW and the energy expended to synthesize tissues that accumulated in the body. This energy was lower in the 8-wk-old group, which had a lower ΔLT/ΔBW in comparison to the 4-wk-old group, but was not affected by exercise. The regression curve revealed that the energy expended to synthesize LT was 2.9 kcal/g, while that expended to synthesize AT was 1.1 kcal/g. Therefore, combined with the energy accumulated to the tissues, the energy required to accumulate LT is approximately 4.0 kcal/g, while that required to accumulate AT is approximately 8.5 kcal/g.

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.

Secondary syphilis in the third trimester of pregnancy.

Syphilis infections discovered late in pregnancy, as in this case, may not be treated long enough for delivery. The Japanese guidelines should be revised because they do not describe the mode of delivery for pregnant women infected with syphilis.

Evaluation of Energy Balance Estimated From Total Energy Expenditure and Body Composition Changes in Junior Sumo Wrestlers: An Observational Study Over Six Months.

Background Sumo is a sport that requires wrestlers to develop their physique from childhood for athletic advantage. However, the energy expenditure and energy balance required for the growth of junior Sumo wrestlers remain unclear. This study aimed to determine the energy balance of junior Sumo wrestlers over six months using doubly labeled water (DLW) and bioelectrical impedance analysis (BIA). Methodology A total of 12 male Sumo wrestlers were affiliated with a local Sumo club (average age = 15 ± 1 years). The total energy expenditure (TEE) was measured using DLW, whereas body composition was evaluated using BIA. Daily physical activity was quantified using a tri-accelerometer (Active style Pro HJA-750C). Results The TEE was 4,194 ± 734 kcal/day, while daily physical activity without training was 786 ± 50 minutes. Within six months, the body weight increased by 2.0 ± 3.2 kg, fat-free mass (FFM) was augmented by 2.1 kg, while fat mass did not change significantly. The surplus energy accumulated was 5.6 ± 213 kcal/day. Conclusions The excess energy of junior Sumo wrestlers predominantly increases their FFM. To increase their physical prowess, wrestlers adhere to a lifestyle characterized by high-intensity training and attenuated daily physical activity.

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.

Later efficacy of nusinersen treatment in adult patients with spinal muscular atrophy: A retrospective case study with a median 4-year follow-up.

BACKGROUND: Spinal muscular atrophy (SMA) is a hereditary neuromuscular disorder characterized by skeletal muscle atrophy and weakness. New treatments for SMA have been developed namely, the drugs nusinersen, onasemnogene abeparvovec, and risdiplam. However, there are limited reports on their effects on adult patients with SMA, particularly over long periods. Therefore, this study aimed to determine the efficacy of nusinersen treatment in adult patients with SMA. METHODS: We retrospectively reviewed patients with SMA type 2 or 3 who received nusinersen treatment between January 2018 and January 2023. All patients were evaluated using the Hammersmith Functional Motor Scale-Expanded (HFMSE) before the commencement of nusinersen treatment, and the change with respect to the baseline HFMSE score was compared. RESULTS: A total of six patients, three patients each with SMA type 2 or 3, were treated with nusinersen. The median age of the patients before the commencement of nusinersen treatment was 51.5 years (range, 33-59 years), and the median treatment period was 50.5 months (range, 33-57 months). Three patients showed an increased tendency of improvement on the HFMSE at 15-26 months after nusinersen treatment, and the HFMSE score was maintained in two patients. Significant adverse events were observed in three patients: one subdural hematoma, one incidental bone fracture, and one cheek dermatofibrosarcoma. CONCLUSIONS: Nusinersen treatment showed later efficacy in adult patients with SMA type 2 or 3. The distinct efficacy of nusinersen requires further investigation using a large number of cases and a long follow-up period.

Clinical features and a mutation with late onset of limb girdle muscular dystrophy 2B.

OBJECTIVE AND METHODS: Dysferlin encoded by DYSF deficiency leads to two main phenotypes, limb girdle muscular dystrophy (LGMD) 2B and Miyoshi myopathy. To reveal in detail the mutational and clinical features of LGMD2B in Japan, we observed 40 Japanese patients in 36 families with LGMD2B in whom dysferlin mutations were confirmed. RESULTS AND CONCLUSIONS: Three mutations (c.1566C>G, c.2997G>T and c.4497delT) were relatively more prevalent. The c.2997G>T mutation was associated with late onset, proximal dominant forms of dysferlinopathy, a high probability that muscle weakness started in an upper limb and lower serum creatine kinase (CK) levels. The clinical features of LGMD2B are as follows: (1) onset in the late teens or early adulthood, except patients homozygous for the c.2997G>T mutation; (2) lower limb weakness at onset; (3) distal change of lower limbs on muscle CT at an early stage; (4) impairment of lumbar erector spinal muscles on muscle CT at an early stage; (5) predominant involvement of proximal upper limbs; (6) preservation of function of the hands at late stage; (7) preservation of strength in neck muscles at late stage; (8) lack of facial weakness or dysphagia; (9) avoidance of scoliosis; (10) hyper-Ckaemia; (11) preservation of cardiac function; and (12) a tendency for respiratory function to decline with disease duration. It is important that the late onset phenotype is found with prevalent mutations.

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.

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.

Body Cell Mass to Fat-Free Mass Ratio and Extra- to Intracellular Water Ratio Are Related to Maximal Oxygen Uptake.

Fat-free mass (FFM) is a heterogeneous compartment comprising body cell mass (BCM), intracellular water (ICW), extracellular solids, and extracellular water (ECW). The BCM/FFM and ECW/ICW ratios vary among individuals and decrease with age. This study aimed to determine whether BCM/FFM and ECW/ICW ratios are predictors of maximal oxygen uptake (V̇̇O2peak) independently of age, sex, and objectively measured physical activity (PA). A total of 115 Japanese males and females, aged 55.3 ± 8.0 years (mean ± standard deviation), were included in the study. Anthropometry, explosive leg muscle power, and V̇̇O2peak were measured, and BCM, FFM, ICW, and ECW were estimated. Step count and PA were objectively measured using a triaxial accelerometer. Blood flow volume was assessed using ultrasonography. BCM and ICW were negatively correlated with age, whereas FFM and ECW were not significantly correlated with age. FFM, ICW/ECW, BCM/FFM, step counts, moderate and vigorous PA, and leg muscle power were positively correlated with V̇̇O2peak, even after adjusting for age and sex (p < .05). Multiple regression analysis indicated that either BCM/FFM or ECW/ICW, leg power, and objectively measured PA were associated with V̇̇O2peak independent of age, sex, and FFM. Blood flow volume was significantly correlated with ECW (p < .05), but not with BCM. The BCM/FFM and ECW/ICW ratios were significant predictors of V̇̇O2peak, independent of age, sex, FFM, leg power, and objectively measured PA.