Publications by authors named "Kime R"

Article Synopsis
  • This study explored how oxygen levels change in skeletal muscles during body-weight exercises like Bulgarian split squats and push-ups, focusing on slow movements and sustained force.
  • Thirteen untrained young males participated, and researchers used near-infrared spectroscopy to measure changes in oxygenated and deoxygenated hemoglobin in specific muscles during the exercises.
  • Results indicated that oxygen dynamics varied significantly between different muscles, showing continuous deoxygenation in some areas during squats while revealing distinct patterns in push-ups, suggesting that individual variations in exercise skills could affect outcomes.
View Article and Find Full Text PDF
Article Synopsis
  • Near-infrared spectroscopy (NIRS) has been used for over 30 years to assess skeletal muscle oxidative function during exercise, utilizing indicators like the deoxygenation rate and reoxygenation speed.
  • These indicators correlate well with various muscle characteristics and have applications in studying chronic health issues, notably in patients with ischaemic heart failure.
  • Despite advancements, challenges exist in using NIRS for measurement, particularly due to factors like subcutaneous adipose tissue thickness and variable mean pathlength during exercises, which can skew results and comparisons among different populations.
View Article and Find Full Text PDF

Brown adipose tissue (BAT) may be effective in preventing obesity and type II diabetes; however, there are no established reports on exercise-induced changes in BAT. This study focused on BAT variability in women undergoing resistance training (RT) interventions twice weekly for 10 weeks in cold environments. Fifteen participants were recruited: seven were randomly assigned to an RT group and eight to a control (CT) group.

View Article and Find Full Text PDF
Article Synopsis
  • The study explored how Nattokinase (NK) affects skin temperature after cold water immersion, focusing on blood flow's role in regulating skin temperature.
  • Conducted with nine healthy men in a double-blinded, placebo-controlled design, the research tested NK against a placebo before the participants immersed their hands in cold water for one minute.
  • Results showed that participants who took NK experienced a quicker recovery of skin temperature compared to the placebo group, suggesting NK might help prevent excessive blood vessel constriction, especially beneficial for individuals sensitive to cold.
View Article and Find Full Text PDF
Article Synopsis
  • While treatments for human African trypanosomiasis (HAT) have advanced, new drugs are still needed as eradication becomes feasible.
  • Researchers developed 2,4-diaminothiazoles that show strong effectiveness against the parasite causing HAT, using phenotypic screening to enhance their drug-like properties.
  • Despite promising initial results, the compounds failed to effectively treat the severe stage of the disease due to a shift from a destructive to a static action mechanism, highlighting a need for drugs that actively kill the parasite.
View Article and Find Full Text PDF

The aim of this study was to compare systemic and quadriceps muscle O dynamics between aerobic capacity-matched subjects without (NAP; n = 5) and with (CON; n = 13) attenuation point in deoxygenated haemoglobin concentration (deoxy-Hb) at vastus lateralis (AP) during ramp cycling exercise. Muscle O saturation (SmO) and deoxy-Hb were monitored at the vastus lateralis (VL), rectus femoris (RF), and vastus medialis (VM) by spatial resolved near infrared spectroscopy during exercise. Cardiac output (CO) and pulmonary O uptake (VO) were also continuously measured.

View Article and Find Full Text PDF

There is no evidence of the effect of exercise training on human brown-like adipose tissue vascular density (BAT-d). Here, we report whether whole-body strength training (ST) in a cold environment increased BAT-d. The participants were 18 men aged 20-31 years.

View Article and Find Full Text PDF

Background And Objective: The importance of brown adipose tissue (BAT) is well recognized in healthy infants and children. However, information regarding age-related changes in BAT vascular density (BAT-d) and the impact of BAT-d on body adiposity are lacking. This study aimed to evaluate the normal values of BAT-d, factors influencing BAT-d, and the impact of BAT-d on body adiposity in healthy infants and children.

View Article and Find Full Text PDF

This study examined the relationship between plasma amino acid (AA) concentrations, including branched-chain AAs, and brown adipose tissue density (BAT-d). One hundred and seventy-three subjects (69 men, 104 women) aged 22-68 years were recruited during the winter season. AAs were comprehensively quantified using liquid chromatography-time-of-flight-mass spectrometry.

View Article and Find Full Text PDF

Previous studies have reported that the reduced scattering coefficient (μ') in the vastus lateralis changes during ramp-incremental exercise due to blood volume changes or accumulation of metabolic by-products. We aimed to clarify the influences of deoxygenation and blood volume changes during exercise on μ' dynamics in subjects with various aerobic capacities. Twenty-three healthy young men participated in this study.

View Article and Find Full Text PDF

The primary symptom in patients with chronic heart failure (CHF) is exercise intolerance. Previous studies have reported that reduced exercise tolerance in CHF can be explained not only by cardiac output (a central factor) but also by reduced skeletal muscle aerobic capacity (a peripheral factor). Although exercise training in CHF improves exercise tolerance, few studies have evaluated the effects of exercise training on each specific central and peripheral factor in CHF.

View Article and Find Full Text PDF
Article Synopsis
  • The study compared muscle oxygen dynamics during exercise across three age groups: elderly (73 years), middle-aged (50 years), and young adults (25 years), all performing ramp bicycle exercises to exhaustion.
  • Results showed that elderly participants had lower muscle oxygen saturation and oxygenated hemoglobin levels compared to the other groups, while deoxygenated and total hemoglobin levels were similar across all ages.
  • The findings suggest that muscle oxygen dynamics are relatively maintained in early aging stages but decline in later stages, likely due to reduced oxygen delivery, and different mechanisms affect peak oxygen uptake between age groups.
View Article and Find Full Text PDF

Purpose: Near-infrared spectroscopy (NIRS), performed with a commonly available noninvasive tissue oxygenation monitoring device, is based on the modified Beer-Lambert law (MBLL). Although NIRS based on MBLL (NIRSMBLL) assumes that the optical path length (PL) is constant, the effects of changes in PL during exercise on muscle oxygenation calculated by MBLL are still incompletely understood. Thus, the purposes of this study were to examine the changes in optical properties during ramp incremental exercise and to compare muscle oxygen dynamics measured by time-resolved NIRS with those calculated based on MBLL.

View Article and Find Full Text PDF

Capsinoids are some of the most promising ingredients to increase energy expenditure (EE) due to brown adipose tissue (BAT) activation. However, there is limited information regarding the effect of prolonged capsinoid ingestion (CI) on BAT activity and resting EE (REE) in healthy, middle-aged, normal to overweight subjects (Sub) with distinct BAT characteristics. We examined the changes in BAT density (BAT-d), using near-infrared time-resolved spectroscopy, and REE/kg induced by daily CI.

View Article and Find Full Text PDF

Brown adipose tissue (BAT) mediates adaptive thermogenesis upon food intake and cold exposure, thus potentially contributing to the prevention of lifestyle-related diseases. F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) with computed tomography (CT) (FDG-PET/CT) is a standard method for assessing BAT activity and volume in humans. FDG-PET/CT has several limitations, including high device cost and ionizing radiation and acute cold exposure necessary to maximally stimulate BAT activity.

View Article and Find Full Text PDF

Brown adipose tissue (BAT) plays a role in adaptive thermogenesis in response to cold environments and dietary intake via sympathetic nervous system (SNS) activation. It is unclear whether physical activity increases BAT density (BAT-d). Two-hundred ninety-eight participants (age: 41.

View Article and Find Full Text PDF

Background/objectives: The thermogenic function of brown adipose tissue (BAT) is generally activated in winter and tightly regulated through various metabolic processes. However, the mechanisms mediating these changes have not been elucidated in humans. Here, we investigated the relationships between BAT density (BAT-d) and lipid metabolites in plasma from men and women in the winter and summer.

View Article and Find Full Text PDF

Near-infrared time-resolved spectroscopy (NIR) can quantitatively evaluate mean optical path length (MPL). Since an increase in optical absorbers in the NIR region (e.g.

View Article and Find Full Text PDF
Article Synopsis
  • The study compared muscle oxygen dynamics during exercise between overweight (OW) and normal-weight (NW) women who had similar aerobic capacities.
  • Overweight women showed higher muscle oxygen saturation (SmO) and lower levels of deoxygenated hemoglobin and total hemoglobin changes compared to normal-weight women during graded treadmill exercise.
  • The findings indicate that despite matching pulmonary oxygen uptake, overweight adults had reduced muscle blood volume and oxygen extraction during exercise, which correlated with their peak aerobic capacity.
View Article and Find Full Text PDF
Article Synopsis
  • - Brown adipose tissue (BAT) could help prevent lifestyle-related diseases, and this study investigates the use of near-infrared time-resolved spectroscopy (NIR) to measure human BAT density (BAT-d).
  • - Key parameters measured by NIR include total hemoglobin, oxygenated hemoglobin, deoxygenated hemoglobin, and reduced scattering coefficient, specifically in the supraclavicular region where BAT is found.
  • - Results indicate that total hemoglobin and oxygenated hemoglobin levels increase in winter compared to summer and are associated with cold-induced thermogenesis, suggesting NIR is an effective, quick, and non-invasive way to assess BAT density.
View Article and Find Full Text PDF

Fat layer thickness (FLT) affects near infrared spectroscopy (NIRS) measurement. The aim of this study was to determine an indicator of muscle function with less influence of FLT, even without normalization, by comparing muscle O dynamics during exercise in subjects with similar physical characteristics except for FLT. Healthy male subjects with thick FLT (n = 5, FLT: 5.

View Article and Find Full Text PDF

The aim of this study was to test the effects of aerobic cycling training on O dynamics in several leg muscles in early post-myocardial infarction (post-MI). Fifteen post-MI patients were divided into a 12-week training group (TR, n = 9) or a control/non-training group (CON, n = 6). All participants performed ramp bicycle exercise until exhaustion at two times: within 12-35 days of their MI and then again 12 weeks later.

View Article and Find Full Text PDF

F18-fluorodeoxyglucose (FDG)-positron emission tomography (PET) along with computed tomography (CT) is a standard method for assessing brown adipose tissue (BAT) activity. We tested the usefulness of near-infrared time-resolved spectroscopy (NIRTRS) as a simple and noninvasive method for evaluating BAT density (BAT-d) by examining the effects of some factors known to influence BAT activity. The total hemoglobin concentration as a parameter of BAT-d was evaluated using NIRTRS in the supraclavicular region in 413 Japanese individuals.

View Article and Find Full Text PDF

The aim of this study was to investigate the effects of 8 weeks of training on O dynamics in university rugby players. University rugby players (n = 15) participated in 5 strength training sessions and 4 field-based training sessions per week for 8 weeks. Before and after 8-weeks' training, the subjects performed ramp cycling exercise until exhaustion.

View Article and Find Full Text PDF

The aim of this study was to compare the muscle oxygen dynamics between early post-myocardial infarction (n = 12; MI) and age-matched elderly subjects without MI (n = 12; CON) in several leg muscles during ramp cycling exercise. Muscle oxygen saturation (SmO), deoxygenated-hemoglobin concentration (∆deoxy-Hb), and total-hemoglobin concentration (∆total-Hb) were monitored continuously at the distal site of vastus lateralis (VLd), proximal site of the vastus lateralis (VLp), rectus femoris (RF), vastus medialis (VM), gastrocnemius medialis (GM), and tibialis anterior (TA) muscles by near infrared spatial resolved spectroscopy. At given absolute workloads, higher SmO was observed at VLd, VLp, RF, and VM in MI, compared to CON.

View Article and Find Full Text PDF