Motohiko Miyachi

Waseda University | Sōdai · Faculty of Sport Sciences

Context Lean body mass is essential for health, yet consensus regarding the effectiveness of protein interventions in increasing lean body mass is lacking. Objective The aim of this systematic review was to evaluate the dose–response relationship of the effects of protein intake on lean body mass. Data Sources The PubMed and Ichushi-Web databases w...

Background Inter-individual variations in gut microbiota composition are observed even among healthy populations. The gut microbiota may exhibit a unique composition depending on the country of origin and race of individuals. To comprehensively understand the link between healthy gut microbiota and host state, it is beneficial to conduct large-scal...

Background In an effort to increase people’s adherence to active lifestyles, contemporary physical activity (PA) guidelines now include low-dose PA. Methods PA was evaluated in 583 participants of the Nutritional and Physical Activity Intervention Study (NEXIS) cohort (30–65 years old); 349 inactive participants (MVPA, 2.7 ± 1.0 MET-h/day) were ra...

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...

This study investigated the effects of white meat, such as chicken, intake combined with resistance training on muscle mass and strength in the elderly women, and whether the underlying mechanism involves changes in the gut microbiota. Ninety‐three volunteers (age 59–79 years) were randomly allocated to sedentary control with placebo (Sed + PL) or...

The differences in the association of objectively measured physical activity with disability between frail and non-frail older adults remain unclear. We (1) evaluated the dose-dependent relationship between daily steps and disability in older adults with and without frailty and (2) examined the interaction between steps and frailty status in relati...

Background Resistance training is a well‐known exercise therapy for preventing and improving lacks of muscle mass, strength, and quality with advances in age; however, its effects on arterial stiffness are not beneficial. Additionally, a higher intake of protein, which is an effective nutrient for muscle health, results in lower arterial stiffness....

Background Reports that collect and organize dietary reference intake (DRI) data for military operations in different countries and regions worldwide are limited.This scoping review aimed to collect and organize information on the status of formulating a DRI for military operations in each country. Methodology For the information search, we querie...

Objective Barley, abundant in β-glucan, a soluble dietary fiber, holds promise in obesity prevention. Given the microbial metabolism of dietary fiber in the gastrointestinal tract, we investigated the role of gut microbiota in non-obese individuals consuming high levels of barley. Methods Our study enrolled 185 participants from “The cohort study...

Urban design is the science (not an art) of (re)building and (re)arranging the built environment to influence people’s behaviour. It can influence stress through several physiological, psychological, and social mechanisms. This interdisciplinary paper aims to offer a comprehensive framework on how urban design attributes affect stress through physi...

Background Sarcopenic obesity (SO) is defined as a decrease in lean body mass and an increase in body fat mass (BFM) due to aging. Detecting SO in elderly women is important from the perspective of extending healthy life expectancy. While various indices of SO are currently used, there is no global consensus regarding diagnostic criteria for SO. Th...

Aims High non-fasting triglycerides (TG) concentration is linked to the development of atherosclerosis, and physical activity is commonly recommended to reduce postprandial TG concentration and cardiovascular diseases. Previous studies have demonstrated that acute whole-body (walking and running) or lower-body (leg cycling) aerobic exercise reduces...

Objective Water is an essential nutrient for all organisms and is important for maintaining life and health. We aimed to develop a biomarker-calibrated equation for predicting water turnover (WT) and pre-formed water (PW) using the doubly labelled water (DLW) method. Design Cross-sectional study. Setting General older population from the Kyoto–Ka...

Background/objectives While some dietary guidelines have established daily water requirements for adults, those for older adults are not well defined. Factors associated with water turnover (WT), indicating water requirements and preformed water (PW), referring to fluids consumed from food and beverages, remain poorly understood. Therefore, we aime...

Purpose Body cooling during and after exercise stimulates energy intake (EI). Cooling vests can also reasonably decrease body temperature under various sport occasions. This study examined the acute effects of wearing a cooling vest on EI and appetite after exercise and rest. Methods Fifteen healthy young men underwent four trials randomly in a th...

Objectives Poor cardiorespiratory fitness (CRF) and high body mass index (BMI) increased the risk of developing metabolic Syndrome (MetS) mostly in Caucasians. However, the sex-specific combined association of CRF and BMI on MetS considering health-related behaviors has yet to be thoroughly examined in Japanese. This study aims to investigate the s...

Background There are now many different types of activity trackers, including pedometers and accelerometers, to estimate step counts per day. Previous research has extensively examined step-count measurements using activity trackers across various settings while simultaneously wearing different devices.; however, older adults frequently display dis...

Background The self-monitoring of physical activity is an effective strategy for promoting active lifestyles. However, accurately assessing physical activity remains challenging in certain situations. This study evaluates a novel floor-vibration monitoring system to quantify housework-related physical activity. Objective This study aims to assess...

Media release: https://www.eurekalert.org/news-releases/1040733

Despite accumulating evidence that suggests a unique gut microbiota composition in athletes, a comprehensive understanding of this phenomenon is lacking. Furthermore, seasonal variation in the gut microbiota of athletes, particularly during the off-season, remains underexplored. This study aimed to compare the gut microbiotas between athletic subje...

Media release: https://www.jaist.ac.jp/whatsnew/press/2024/04/10-1.html

Sports science focuses on enhancing athletes’ performance, requiring a multifaceted approach. It is evolving from a purely muscle-centred approach to an interdisciplinary one. This paper investigates built environment design science, a dimension less explored in relation to enhancing athlete performance in sports science. The discussion is divided...

Despite accumulating evidence that suggests a unique gut microbiota composition in athletes, a comprehensive understanding of this phenomenon is lacking. Furthermore, seasonal variation in the gut microbiota of athletes, particularly during the off-season, remains underexplored. This study aimed to compare the gut microbiotas between athletic subje...

Background Physical activity or biomarker-calibrated energy intake (EI) alone is associated with mortality in older adults; the interaction relationship between the combined use of both factors and mortality has not been examined. We evaluated the relationship between mortality and calibrated EI and step counts in older adults. Methods This prospe...

Aim The gut microbiota has emerged as a new intervention target for sarcopenia. Prior studies in humans have focused on the association between gut microbiota and skeletal muscle quantity, while the evidence on muscle function and quality is lacking. This study aimed to identify gut microbiota genera associated with skeletal muscle function, quanti...

The genetic underpinnings of elite sprint performance remain largely elusive. For the first time, we uncovered rs10196189 (GALNT13) in the cross-ancestry, genome-wide analysis of elite sprint and power-oriented athletes and their controls from Jamaica, the USA, and Japan, and replicated this finding in two independent cohorts of elite European athl...

Although better diet quality is inversely associated with mortality risk, the association between diet quality and mortality remains unclear in frail and non-frail older adults. Thus, we aimed to examine this association in older Japanese adults. A prospective cohort study. We used the data of 8,051 Japanese older adults aged ≥65 years in the Kyoto...

Background Although water is essential to the maintenance of health and life, standard values for human water requirements are yet to be determined. This study aimed to evaluate the distribution of water turnover (WT) according to sex and age, estimated using a prediction equation, in Japanese adolescents and adults. Methods This cross-sectional s...

Escherichia coli harboring polyketide synthase (pks⁺E. coli) has been suggested to contribute to colorectal cancer development. Physical activity is strongly associated with lower colorectal cancer risks, but its effects on pks⁺E. coli remain unclear. The aim of this study was to investigate the association between pks⁺E. coli prevalence and physic...

Objective This study aimed to determine the effects of different energy loads on the gut microbiota composition and the rates of energy and nutrient excretion via feces and urine. Method s A randomized crossover dietary intervention study was conducted with three dietary conditions: overfeeding (OF), control (CON), and underfeeding (UF). Ten healt...

Aerobic capacity is a fitness measure reflecting the ability to sustain whole-body physical activity as fast and long as possible. Identifying the distribution of aerobic capacity in a population may help estimate their health status. This study aimed to estimate standard values of aerobic capacity (peak oxygen uptake [V˙O2peak]/kg and anaerobic th...

DNA methylation-based age estimators (DNAm ageing clocks) are currently one of the most promising biomarkers for predicting biological age. However, the relationships between cardiorespiratory fitness (CRF), measured directly by expiratory gas analysis, and DNAm ageing clocks are largely unknown. We investigated the relationships between CRF and th...

BACKGROUND The self-monitoring of physical activity is an effective strategy for promoting active lifestyles. However, accurately assessing physical activity remains challenging in certain situations. This study evaluates a novel floor-vibration monitoring system to quantify housework-related physical activity. OBJECTIVE This study aims to assess...

A cross-sectional study involving 224 healthy Japanese adult females explored the relationship between ramen intake, gut microbiota diversity, and blood biochemistry. Using a stepwise regression model, ramen intake was inversely associated with gut microbiome alpha diversity after adjusting for related factors, including diets, Age, BMI, and stool...

Introduction: The gut microbiome plays a fundamental role in host homeostasis through regulating immune functions, enzyme activity, and hormone secretion. Exercise is associated with changes in gut microbiome composition and function. However, few studies have investigated the gut microbiome during training periodization. The present study aimed t...

Introduction: The prevalence of frailty is on the rise with the aging population and increasing life expectancy, which often is accompanied by comorbidities. Frailty can be effectively detected using Frailty index such as KCL index. Early detection of frailty allows applying measures that reduce the conversion rate to frail, and improve the quality...

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 (V̇O...

Background: Barley, a grain rich in soluble dietary fiber β-glucan, is expected to lower blood pressure. Conversely, individual differences in its effects on the host might be an issue, and gut bacterial composition may be a determinant. Methods: Using data from a cross-sectional study, we examined whether the gut bacterial composition could exp...

DNA methylation-based age estimators (DNAm aging clocks) are currently one of the most promising biomarkers for predicting biological age. However, the relationships between objectively measured physical fitness, including cardiorespiratory fitness, and DNAm aging clocks are largely unknown. We investigated the relationships between physical fitnes...

This study aimed to identify the modifiable cardiovascular risk factors associated with longitudinal changes, which are nine functional and structural biological vascular aging indicators (BVAIs), to propose an effective method to prevent biological vascular aging. We conducted a longitudinal study of 697 adults (a maximum of 3636 BVAI measurements...

Objectives: Frailty has been shown to be a mediator of the risk of excess death due to depression in older adults, although this relationship has not been sufficiently investigated. Our objective was to evaluate this relationship. Methods: We used data from 7,913 Japanese people aged≥65 years who participated in the Kyoto-Kameoka prospective coh...

Background: This study aimed to elucidate whether total body composition or thigh muscularity is more closely associated with lower extremity performance in older women. Methods: Sixty-seven Japanese women aged 60-77 years voluntarily participated in this study. Fat mass (FM) and lean soft tissue mass (LSTM) of each body segment and total body were...

Factors associated with dynamic changes in the objectively measured physical activity have not been well understood. We aimed to 1) evaluate the longitudinal change in the physical activity trajectory according to sex which is associated with age and to 2) determine the factors associated with the dynamic change in physical activity-related variabl...

Background Aerobic capacity, which strongly determines health status, is the ability to sustain whole-body physical activity as fast and as long as possible. This study integrated previously reported data on the aerobic capacity (peak oxygen uptake [VO2peak]/kg and anaerobic threshold [AT]/kg) of Japanese individuals. Additionally, we estimated the...

Purpose: Whether the association between objectively assessed physical activity and mortality differs between adults with versus those without frailty is unclear. We investigated this association in community-dwelling older adults. Methods: This prospective study used the data of 4165 older adults aged 65 years or older from the Kyoto-Kameoka st...

[Purpose] Very few studies have been conducted on the benefits of water exercise for older adults with sarcopenic obesity. Whether the water exercise intervention is effective for improving sarcopenia and/or obesity remains unclear. This study aimed to investigate the effects of water exercise on body composition and components of metabolic syndrom...

Arterial stiffness increases with age and is an independent risk factor for death from future cardiovascular diseases. Habitual exercise has been recommended as one of the effective treatments and prevention for hypertension and cardiovascular diseases. In this presentation, I would like to introduce the results of research on the effects of differ...

Aims This study determined the relationship between intra-individual variability in day-to-day nutrition-related lifestyle behaviors (meal timing, eating window, food intake, movement behaviors, sleep conditions, and body weight) and glycemic outcomes under free-living conditions in adults without type 2 diabetes. Methods We analyzed 104 adults wi...

Dietary plant lignans are converted inside the gut to enterolignans enterodiol (ED) and enterolactone (EL), which have several biological functions, and health benefits. In this study, we characterized the gut microbiome composition associated with enterolignan production using data from a cross−sectional study in the Japanese population. We identi...

The phase angle (PhA), measured via bioelectrical impedance analysis, is considered an indicator of cellular health, where higher values reflect higher cellularity, cell membrane integrity, and better cell function. This study aimed to examine the relationship between PhA and exercise habits or objectively measured physical activity. We included 11...

Previous cross-sectional studies have indicated that low relative appendicular lean mass (ALM) against body weight (divided by body weight, ALM/Wt, or divided by body mass index, ALM/BMI) was negatively associated with metabolic syndrome (MetS). Conversely, previous cross-sectional studies have indicated that the absolute ALM or ALM divided by squa...

Objectives: We aimed to examine the relationship between the fat-free mass index (FFMI; FFM/height2) and appendicular skeletal muscle mass index (ASMI; ASM/height2), measured using both bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA), and investigate the effects of age and obesity. We also evaluated the suitabilit...

Background: Whether sleep quality and duration-combination assessed from multiple domains are strongly associated with mortality risk in older adults remains unelucidated. We aimed to clarify these relationships. Methods: We enrolled 7,668 older (age ≥65) Japanese adults in the Kyoto-Kameoka prospective cohort study who provided valid responses to...

Purpose: To examine how physical activity (PA) and sitting time (ST) are associated with mortality in older Japanese adults. Methodology: We used the data of 10,233 older Japanese adults aged ≥65 years who provided valid responses to the International Physical Activity Questionnaire-Short Form (IPAQ-SF) by a mail survey. Both PA and ST were asse...

Background Protein supplementation augments muscle strength gain during resistance training. Although some studies focus on the dose-response relationship of total protein intake to muscle mass or strength, the detailed dose-response relationship between total protein intake and muscle strength increase is yet to be clarified, especially in the abs...

We aimed to verify the combined use of two frailty tools in predicting mortality in older adults. We used the data of 10,276 Japanese older adults (aged ≥ 65 years) who provided valid responses to two frailty assessment tools in a mail survey in Japan’s Kyoto‒Kameoka Prospective cohort study. Frailty status was categorized into four groups dependin...

The gut microbiome is an important determinant in various diseases. Here we perform a cross-sectional study of Japanese adults and identify the Blautia genus, especially B. wexlerae , as a commensal bacterium that is inversely correlated with obesity and type 2 diabetes mellitus. Oral administration of B. wexlerae to mice induce metabolic changes a...

Background The Olympic Games represent an opportunity to create a ‘physical activity legacy’ that promotes physical activity at the population level in the host nations and cities. However, previous studies showed little increase in population-level physical activity following the Olympics. The upsurge of public interest in sports and physical acti...

Purpose While the association between diet quality and mortality has been previously demonstrated, the association between frailty and diet quality has not been evaluated well. This study aimed to investigate the association between diet quality and prevalence of both physical and comprehensive frailty, using two validated tools, in a community-bas...

Background Many activity trackers have been developed, but steps can still be inconsistent from one monitor to another. Research question What are the differences and associations between the steps of 13 selected consumer-based and research-grade wearable devices during 1 standardized day in a metabolic chamber and 15-day free-living trials? Meth...

Background/Objective: The 2020 Tokyo Olympics and Paralympic was held in 2021, although postponed due to the spread of COVID-19. This event might have an impact on physical activity (PA) of children and adolescents, but the national data on PA during the pandemic were not available. Therefore, the goal of the 2022 Japan Report Card on Physical Acti...

Little is known about the optimal daily magnesium (Mg) intake for individuals with high levels of physical activity. The aim of this study was to clarify the optimal dietary Mg intake for people with high levels of physical activity in a scoping review. In this review, we searched MEDLINE and Japan Medical Abstracts Society for studies published up...

In older adults, the quantitative decline of the quadriceps femoris is associated with the augmentation of difficulty in the execution of a stand-up task. However, it is unclear whether the cross-sectional areas (CSAs) of individual thigh muscles differ between older adults who can stand up from a 40-cm-height chair on a single leg and those who ca...