Stationarity of the Special Relationship Between the Geographical Distribution of Body Size and Day Length in Japanese Adolescents: Spatial and Temporal Analysis Using a GTWR Model.

Objectives: Northern Japanese children tend to have larger physiques; however, the underlying cause remains unknown. Previous geographical correlation analyses revealed an unusual trend; effective day length was negatively correlated with height and positively correlated with weight (adjusted for height). This paradoxical relationship suggests a thyroid hormone-like effect and possible photoperiodic response.

The fan cooling vest use reduces thermal and perceptual strain during outdoor exercise in the heat on a sunny summer day.

The fan cooling vest is coming into very common use by Japanese outdoor manual workers. We examined that to what extent using this vest reduces thermal strain and perception during outdoor exercise in the heat on a sunny summer day. Ten male baseball players in high school conducted two baseball training sessions for 2-h with (VEST) or without (CON) a commercially available fan cooling vest on a baseball uniform.

Associations of body composition with physical activity, nutritional intake status, and chronotype among female university students in Japan.

Background: Having higher muscle mass in early adulthood is an important factor in preventing sarcopenia. However, university students undergo lifestyle changes compared to their high school years, which may lead to changes in body composition, such as an increase in body fat and a decrease in muscle mass. The study aimed to investigate the association between body composition and lifestyle behaviors, including chronotype, among Japanese female university students, due to the prevalence of underweight among young females in the country.

Thermal strain is greater in the late afternoon than morning during exercise in the gym without airflow and air conditioning on a clear summer day.

Introduction: There are no reports examining the time-of-day effect on team training sessions in the gym without airflow and air conditioning on thermal strain in the summer heat. We investigated this effect during badminton training sessions on a clear summer day.

Methods: Nine male high school badminton players (Mean ± SD; age 17.

Association between Normal Weight Obesity and Skeletal Muscle Mass Index in Female University Students with Past Exercise Habituation.

This study investigated the relationship between normal weight obesity (NW-O) and skeletal muscle mass index (SMI) in 120 female university students who participated in sporting activities during junior and senior high school. The current physical activity level (PAL) was estimated by a factorial method using 24-h physical activity recall. The body mass index (BMI) of the participants ranged from 18.

Determining total energy expenditure in 3-6-year-old Japanese pre-school children using the doubly labeled water method.

The doubly labeled water (DLW, HO) method for calculating the total production of CO over several days is currently considered to be the most accurate technique for the measurement of total energy expenditure (TEE), and the results obtained using this method have been used to review energy requirements. Presently, there is limited data available on TEE in Japanese children. The objective of this study was to assess the TEE in pre-school Japanese children using the DLW method.

The CLOCK 3111T/C polymorphism is associated with hour-by-hour physical activity levels only on weekends among Japanese male and female university students.

Background: CLOCK 3111T/C has been shown to be closely associated with morningness-eveningness, such as sleep-wake rhythms in healthy humans. However, previous studies examined the physical activity (PA) in a single day, and no study has investigated the relationships between CLOCK 3111T/C polymorphism and PA for an entire week. It was hypothesized that the CLOCK 3111T/C polymorphism might be associated with diurnal PA patterns, especially on the weekends.

An association between the physical activity level and skeletal muscle mass index in female university students with a past exercise habituation.

Objectives: This study aims to investigate the association between skeletal muscle mass index (SMI) and physical activity among female university students who had exercise habituation in junior and high school.

Methods: The body composition of 120 Japanese female students was measured using the bioelectrical impedance analysis (BIA) method, and their physical activity level (PAL) was measured using a factorial method. Based on the 'Dietary Reference Intakes for Japanese' (DRIs-J), according to the Ministry of Health, Labour and Welfare, PAL (24-h energy consumption/basal metabolic rate) classifications were defined as low-PAL (PAL < 1.

Relationships among Student-Athletes' Identity, Mental Health, and Social Support in Japanese Student-Athletes during the COVID-19 Pandemic.

The purpose of the two studies was to investigate the relationships among student athletes' identity and mental health during the COVID-19 pandemic. In addition, this study aimed to clarify the relationship between perceived social support from teammates and mental health in student-athletes. Two studies were conducted to investigate and clarify the mental health states of student-athletes in Japan during the COVID-19 pandemic.

Differences in Muscle Activities and Kinematics between Forefoot Strike and Rearfoot Strike in the Lower Limb during 180° Turns.

Background: A forefoot strike (FFS) could be a safer landing technique than a rearfoot strike (RFS) during a cutting motion to prevent anterior cruciate ligament (ACL) injury.

Purpose: This study aimed to determine the joint angles, ground reaction force (GRF), and muscle activity levels associated with FFS and RFS landings during 180° turns.

Study Design: Cross-sectional study.

Male collegiate soccer athletes with severe ankle laxity display increased knee abduction during side-cutting tasks compared to those with only perceived ankle instability.

This study aimed to examine lower limb kinematics during a side-cutting task in male collegiate soccer athletes with severe ankle laxity. Forty-seven participants with a history of ankle sprains and perceived ankle instability were categorized into non-laxity (n = 17), laxity (n = 19), and severe laxity (n = 11) groups using stress radiography tests. Three-dimensional kinematic data during the stance phase of a 45° side-cutting task were analysed.

Longitudinal Physical Development of Future Professional Male Soccer Players: Implications for Talent Identification and Development?

The present study examined if elite youth male association football (soccer) players aged 8-19 y ( = 2,875) from the English talent development system, who ultimately achieved professional status differed in stature, body mass, and physical performance (20-m sprint speed, slalom agility speed, vertical counter-movement jump with arm swing jump height, multistage fitness test distance) compared with their non-professional peers. The study also examined the longitudinal pattern of development of stature, body mass, and physical performance, and if this was different between future professionals and non-professionals, while considering the effects of playing position. Multilevel modeling of the 8,898 individual (player-occasion) data points suggested that from age 12.

Greater thermoregulatory strain in the morning than late afternoon during judo training in the heat of summer.

Purpose: The time-of-day variations in environmental heat stress have been known to affect thermoregulatory responses and the risk of exertional heat-related illness during outdoor exercise in the heat. However, such effect and risk are still needed to be examined during indoor sports/exercises. The current study investigated the diurnal relationships between thermoregulatory strain and environmental heat stress during regular judo training in a judo training facility without air conditioning on a clear day in the heat of summer.

Combined effects of solar radiation and airflow on endurance exercise capacity in the heat.

This study investigated the combined effects of different levels of solar radiation and airflow on endurance exercise capacity and thermoregulatory responses during exercise-heat stress. Ten males cycled at 70% peak oxygen uptake until exhaustion in an environmental chamber (30°C, 50% relative humidity). Four combinations of solar radiation and airflow were tested (800 W⋅m and 10 km⋅h [High-Low], 800 W⋅m and 25 km⋅h [High-High], 0 W⋅m and 10 km⋅h [No-Low], and 0 W⋅m and 25 km⋅h [No-High]).

Ankle laxity affects ankle kinematics during a side-cutting task in male collegiate soccer athletes without perceived ankle instability.

Objectives: To investigate whether ankle joint laxity alone influences lower limb kinematics during a side-cutting task.

Design: A cross-sectional study.

Setting: Sports medicine research laboratory.

Directions of single-leg landing affect multi-segment foot kinematics and dynamic postural stability in male collegiate soccer athletes.

Background: Understanding lower limb kinematics and postural control in different directions of single-leg landings is critical to evaluate postural control and prevent lower limb injuries. However, foot and ankle kinematics and postural control during single-leg landings in different directions are less known.

Research Question: Does the difference in the direction of single-leg landing affect the foot kinematics on the frontal plane and dynamic postural stability?

Methods: A cross-sectional study was conducted.

Rising vs. falling phases of core temperature on endurance exercise capacity in the heat.

Purpose: Core temperature (T) shows rising (05:00-17:00 h) and falling (17:00-05:00 h) phases. This study examined the time-of-day effects on endurance exercise capacity and heat-loss responses to control T in the heat at around the midpoint of the rising and falling phases of T.

Methods: Ten male participants completed cycling exercise at 70% peak oxygen uptake until exhaustion in the heat (30 °C, 50% relative humidity).

Solar Radiation Exposure Has Diurnal Effects on Thermoregulatory Responses During High-Intensity Exercise in the Heat Outdoors.

Otani, H, Goto, T, Goto, H, Hosokawa, Y, and Shirato, M. Solar radiation exposure has diurnal effects on thermoregulatory responses during high-intensity exercise in the heat outdoors. J Strength Cond Res 33(10): 2608-2615, 2019-This study investigated the diurnal effects of variations in solar radiation associated with changing solar elevation angle on thermoregulatory responses during high-intensity exercise in the heat outdoors.

Day length may make geographical difference in body size and proportions: An ecological analysis of Japanese children and adolescents.

There is a north-south gradient in the body heights of Japanese children. A hypothesis had previously been proposed that differences in thyroid hormone activity induced by geographical differences in effective day length (duration of photoperiod exceeding a predetermined light intensity) might cause the differences in height. If thyroid hormone is involved, the effect should extend to body weight.

High-Intensity Demands of 6-a-Side Small-Sided Games and 11-a-Side Matches in Youth Soccer Players.

Purpose: The purposes of the present study were to examine high-intensity running distance during 6-a-side small-sided games (SSGs) and 11-a-side matches (11M) in youth soccer players using speed and metabolic power approaches and the magnitude of difference between the high-intensity running distance calculated with the 2 approaches.

Method: A total of 11 outfield players (age = 16.3 [0.

Exposure to high solar radiation reduces self-regulated exercise intensity in the heat outdoors.

High radiant heat load reduces endurance exercise performance in the heat indoors, but this remains unconfirmed in outdoor exercise. The current study investigated the effects of variations in solar radiation on self-regulated exercise intensity and thermoregulatory responses in the heat outdoors at a fixed rating of perceived exertion (RPE). Ten male participants completed 45-min cycling exercise in hot outdoor environments (about 31°C) at a freely chosen resistance and cadence at an RPE of 13 (somewhat hard).

Inter-rater reliability and validity of angle measurements using smartphone applications for weight-bearing ankle dorsiflexion range of motion measurements.

Objectives: The purpose of this study was to examine the inter-rater reliability, validity, and error of angle measurements for ankle dorsiflexion range of motion while in the weight-bearing position using a smartphone application.

Design: Reliability and validity study.

Setting: Measurement positions were performed by one experienced examiner.

Development and initial validation of the Morningness-Eveningness Exercise Preference Questionnaire (MEEPQ) in Japanese university students.

The aim of this study was to develop a questionnaire to conveniently assess the diurnal preferences of physical activity (PA) in Japanese university students. A total of 219 subjects completed our novel Morningness-eveningness Exercise Preference Questionnaire (MEEPQ). The MEEPQ consisted of 30 items (15 items for the morning and the same 15 items for the evening) rated on a 5-point Likert scale concerning their preference for participating in PA in the morning and evening.