Using Support Vector Machines to Classify Road Surface Conditions to Promote Safe Driving.

Accurate detection of road surface conditions in adverse winter weather is essential for traffic safety. To promote safe driving and efficient road management, this study presents an accurate and generalizable data-driven learning model for the estimation of road surface conditions. The machine model was a support vector machine (SVM), which has been successfully applied in diverse fields, and kernel functions (linear, Gaussian, second-order polynomial) with a soft margin classification technique were also adopted. Two learner designs (one-vs-one, one-vs-all) extended their application to multi-class classification. In addition to this non-probabilistic classifier, this study calculated the posterior probability of belonging to each group by applying the sigmoid function to the classification scores obtained by the trained SVM. The results indicate that the classification errors of all the classifiers, excluding the one-vs-all linear learners, were below 3%, thereby accurately classifying road surface conditions, and that the generalization performance of all the one-vs-one learners was within an error rate of 4%. The results also showed that the posterior probabilities can analyze certain atmospheric and road surface conditions that correspond to a high probability of hazardous road surface conditions. Therefore, this study demonstrates the potential of data-driven learning models in classifying road surface conditions accurately.

ATP synthase inhibitory factor 1 (IF1), a novel myokine, regulates glucose metabolism by AMPK and Akt dual pathways.

ATPase inhibitory factor 1 (IF1) is an ATP synthase-interacting protein that suppresses the hydrolysis activity of ATP synthase. In this study, we observed that the expression of IF1 was up-regulated in response to electrical pulse stimulation of skeletal muscle cells and in exercized mice and healthy men. IF1 stimulates glucose uptake via AMPK in skeletal muscle cells and primary cultured myoblasts. Reactive oxygen species and Rac family small GTPase 1 (Rac1) function in the upstream and downstream of AMPK, respectively, in IF1-mediated glucose uptake. In diabetic animal models, the administration of recombinant IF1 improved glucose tolerance and down-regulated blood glucose level. In addition, IF1 inhibits ATP hydrolysis by ß-F1-ATPase in plasma membrane, thereby increasing extracellular ATP and activating the protein kinase B (Akt) pathway, ultimately leading to glucose uptake. Thus, we suggest that IF1 is a novel myokine and propose a mechanism by which AMPK and Akt contribute independently to IF1-mediated improvement of glucose tolerance impairment. These results demonstrate the importance of IF1 as a potential antidiabetic agent.-Lee, H. J., Moon, J., Chung, I., Chung, J. H., Park, C., Lee, J. O., Han, J. A., Kang, M. J., Yoo, E. H., Kwak, S.-Y., Jo, G., Park, W., Park, J., Kim, K. M., Lim, S., Ngoei, K. R. W., Ling, N. X. Y., Oakhill, J. S., Galic, S., Murray-Segal, L., Kemp, B. E., Mantzoros, C. S., Krauss, R. M., Shin, M.-J., Kim, H. S. ATP synthase inhibitory factor 1 (IF1), a novel myokine, regulates glucose metabolism by AMPK and Akt dual pathways.

Living High-Training Low for 21 Days Enhances Exercise Economy, Hemodynamic Function, and Exercise Performance of Competitive Runners.

Living high-training low (LHTL) is performed by competitive athletes expecting to improve their performance in competitions at sea level. However, the beneficial effects of LHTL remain controversial. We sought to investigate whether 21 days of LHTL performed at a 3,000 m simulated altitude (fraction of inspired oxygen [FIO2]=14.5%) and at sea level can improve hematological parameters, exercise economy and metabolism, hemodynamic function, and exercise performance compared with living low-training low (LLTL) among competitive athletes. All participants (age = 23.5 ± 2.1 years, maximal oxygen consumption [VO2max] = 55.6 ± 2.5 mL·kg-1·min-1, 3,000 m time trial performance=583.7 ± 22.9 seconds) were randomly assigned to undergo LHTL (n = 12) or LLTL (n = 12) and evaluated before and after the 21 days of intervention. During the 21-day intervention period, the weekly routine for all athletes included 6-day training and 1-day rest. The daily training programs consisted of >4 hours of various exercise programs (i.e., jogging, high-speed running, interval running, and 3,000 m or 5,000-m time trial). The LHTL group resided in a simulated environmental chamber (FIO2 = 14.5%) for >12 hours per day and the LLTL group at sea level under comfortable conditions. The hematological parameters showed no significant interaction. However, LHTL yielded more improved exercise economy, metabolic parameters (oxygen consumption=-152.7 vs 32.4 mL·kg-1·30min-1, η2 = 0.457, p = 0.000; tissue oxygenation index=6.18 vs .66%, η2 = 0.250, p = 0.013), and hemodynamic function (heart rate = -234.5 vs -49.7 beats·30min-1, η2 = 0.172, p = 0.044; stroke volume = 136.4 vs -120.5 mL/30 min, η2 = 0.191, p = 0.033) during 30 minutes of submaximal cycle ergometer exercise corresponding to 80% maximal heart rate before training than did LLTL. Regarding exercise performance, LHTL also yielded more improved VO2max (5.40 vs 2.35 mL·kg-1·min-1, η2 = 0.527, p = 0.000) and 3,000 m time trial performance (-34.0 vs -19.5 seconds, η2 = 0.527, p = 0.000) than did LLTL. These results indicate that compared with LLTL, LHTL can have favorable effects on exercise performance by improving exercise economy and hemodynamic function in competitive runners.

Impact of blood pressure perturbations on arterial stiffness.

Although the associations between chronic levels of arterial stiffness and blood pressure (BP) have been fairly well studied, it is not clear whether and how much arterial stiffness is influenced by acute perturbations in BP. The primary aim of this study was to determine magnitudes of BP dependence of various measures of arterial stiffness during acute BP perturbation maneuvers. Fifty apparently healthy subjects, including 25 young (20-40 yr) and 25 older adults (60-80 yr), were studied. A variety of BP perturbations, including head-up tilt, head-down tilt, mental stress, isometric handgrip exercise, and cold pressor test, were used to encompass BP changes induced by physical, mental, and/or mechanical stimuli. When each index of arterial stiffness was plotted with mean BP, all arterial stiffness indices, including cardio-ankle vascular index or CAVI (r = 0.50), carotid-femoral pulse wave velocity or cfPWV (r = 0.51), brachial-ankle pulse wave velocity or baPWV (r = 0.61), arterial compliance (r = -0.42), elastic modulus (r = 0.52), arterial distensibility (r = -0.32), ß-stiffness index (r = 0.19), and Young's modulus (r = 0.35) were related to mean BP (all P < 0.01). Changes in CAVI, cfPWV, baPWV, and elastic modulus were significantly associated with changes in mean BP in the pooled conditions, while changes in arterial compliance, arterial distensibility, ß-stiffness index, and Young's modulus were not. In conclusion, this study demonstrated that BP changes in response to various forms of pressor stimuli were associated with the corresponding changes in arterial stiffness indices and that the strengths of associations with BP varied widely depending on what arterial stiffness indices were examined.

Efficacy of Daily Walking as a Potential Predictor of Improved Health-Related Quality of Life in Patients with Type 2 Diabetes in Korea.

This study examines whether health-related quality of life (HRQoL) scores differ due to the frequency of walking or physical activity (PA) throughout a week in diabetic patients in Korea. This population-based cross-sectional study used data from the 2018-2021 Korea National Health and Nutrition Examination Survey. The dependent variable was HRQoL scores as measured with EuroQol-5D (EQ-5D). The independent variables were defined as three types of PA: (1) walking; (2) moderate; and (3) vigorous. An estimated population size of 2,376,066 was included in this study. The mean (95% confidence interval (CI)) age of patients was 60.12 years (59.23, 60.81), and 53.0% were female. The mean (95% CI) of EQ-5D was 0.867 (0.857, 0.877). The majority of diabetic patients reported walking daily (39.05%, 95% CI; 36.28-41.81%), while a significant proportion did not engage in moderate (65.45%, 95% CI; 62.79-68.11%) or vigorous (78.38%, 95% CI; 73.02-77.73%) PA at all. After controlling for covariates, EQ-5D scores significantly increased when patients had walked once per week for at least 10 min in the Tobit regression model. The frequency of walking was the most significant predicting factor for better HRQoL in patients with type 2 diabetes.

Readjustment of circadian clocks by exercise intervention is a potential therapeutic target for sleep disorders: a narrative review.

PURPOSE: Circadian clocks are evolved endogenous biological systems that communicate with environmental cues to optimize physiological processes, such as the sleep-wake cycle, which is nearly related to quality of life. Sleep disorders can be treated using pharmacological strategies targeting melatonin, orexin, or core clock genes. Exercise has been widely explored as a behavioral treatment because it challenges homeostasis in the human body and affects the regulation of core clock genes. Exercise intervention at the appropriate time of the day can induce a phase shift in internal clocks. Although exercise is a strong external time cue for resetting the circadian clock, exercise therapy for sleep disorders remains poorly understood. METHODS: This review focused on exercise as a potential treatment for sleep disorders by tuning the internal circadian clock. We used scientific paper depositories, including Google Scholar, PubMed, and the Cochrane Library, to identify previous studies that investigated the effects of exercise on circadian clocks and sleep disorders. RESULTS: The exercise-induced adjustment of the circadian clock phase depended on exercise timing and individual chronotypes. Adjustment of circadian clocks through scheduled morning exercises can be appropriately prescribed for individuals with delayed sleep phase disorders. Individuals with advanced sleep phase disorders can synchronize their internal clocks with their living environment by performing evening exercises. Exercise-induced physiological responses are affected by age, sex, and current fitness conditions. CONCLUSION: Personalized approaches are necessary when implementing exercise interventions for sleep disorders.

Effects of 12 Weeks of Combined Exercise Training in Normobaric Hypoxia on Arterial Stiffness, Inflammatory Biomarkers, and Red Blood Cell Hemorheological Function in Obese Older Women.

BACKGROUND/OBJECTIVES: The present study examined the effect of 12-week combined exercise training in normobaric hypoxia on arterial stiffness, inflammatory biomarkers, and red blood cell (RBC) hemorheological function in 24 obese older women (mean age: 67.96 ± 0.96 years). METHODS: Subjects were randomly divided into two groups (normoxia (NMX; n = 12) and hypoxia (HPX; n = 12)). Both groups performed aerobic and resistance exercise training programs three times per week for 12 weeks, and the HPX group performed exercise programs in hypoxic environment chambers during the intervention period. Body composition was estimated using bioelectrical impedance analysis equipment. Arterial stiffness was measured using an automatic waveform analyzer. Biomarkers of inflammation and oxygen transport (tumor necrosis factor alpha, interleukin 6 (IL-6), erythropoietin (EPO), and vascular endothelial growth factor (VEGF)), and RBC hemorheological parameters (RBC deformability and aggregation) were analyzed. RESULTS: All variables showed significantly more beneficial changes in the HPX group than in the NMX group during the intervention. The combined exercise training in normobaric hypoxia significantly reduced blood pressure (systolic blood pressure: p < 0.001, diastolic blood pressure: p < 0.001, mean arterial pressure: p < 0.001, pulse pressure: p < 0.05) and brachial-ankle pulse wave velocity (p < 0.001). IL-6 was significantly lower in the HPX group than in the NMX group post-test (p < 0.001). Also, EPO (p < 0.01) and VEGF (p < 0.01) were significantly higher in the HPX group than in the NMX group post-test. Both groups showed significantly improved RBC deformability (RBC EI_3Pa) (p < 0.001) and aggregation (RBC AI_3Pa) (p < 0.001). CONCLUSIONS: The present study suggests that combined exercise training in normobaric hypoxia can improve inflammatory biomarkers and RBC hemorheological parameters in obese older women and may help prevent cardiovascular diseases.

Investigating the effect of road lighting color temperature on road visibility in night foggy conditions.

Night foggy road conditions limit visibility distance of drivers and are associated with higher accident and fatality rates than other weather conditions. Therefore, ensuring road visibility in night foggy road is critical. However, it is difficult to reproduce fog on a real road and only a few studies have researched foggy road conditions and visibility in a laboratory as a small scale. Previous studies have suggested that a color temperature of road lighting is related to visibility. However, many have only investigated the effects of relative transmittance in limited indoor experiments, and the impacts of differences in transmittance on visibility have thus far not been studied in real-scale conditions. In this study, a real-scale test involving 91 subjects was conducted to investigate how the visibility distance under night foggy conditions is affected by different lighting color temperatures. Based on the real scale experiments, the correlation between the visibility distance and lighting color temperature was derived. Road lighting with a low color temperature (i.e., yellow) was found to provide longer visibility distances than that with high color temperatures under night foggy conditions having measured visibility of approximately 102m. The impact of the differences in lighting color increased as the visibility distance decreased. In contrast, road lighting with a high color temperature (i.e., white) improved driver visibility in higher-visibility conditions. Therefore, this study confirmed the correlation between lighting color temperature and visibility distance for different visibility conditions and could serve as a foundation for the development of roadway design standards as well as future studies.

Protein-Added Healthy Lunch-Boxes Combined with Exercise for Improving Physical Fitness and Vascular Function in Pre-Frail Older Women: A Community-Based Randomized Controlled Trial.

Purpose: Preventive or therapeutic interventions are key to maintaining independence in pre-frail and/or frail elderly. Therefore, we investigated whether multi-component interventions were effective in physical fitness levels and vascular functions in pre-frail older women. Patients and Methods: Sixty participants aged ≥ 65 years (81.5 ± 4.3 yrs) were divided equally into control group, diet group, aerobic exercise and diet group, and aerobic exercise with electromyostimulation and diet group. For 8 weeks, the participants received a set of protein-added meals twice daily on weekdays. The aerobic exercise groups performed 45 mins of stepping exercise at 50-70% of the maximal heart rate for 3 days/week, and the aerobic exercise with electromyostimulation was applied on each limb in 8 weeks. Blood pressure, physical fitness, cardiovascular biomarkers, pulse wave velocity, and flow-mediated dilation were measured before and after the 8-week. Results: There were no group differences in age, height, weight, body mass index, free fat mass, and %body fat at baseline. The right grip strength significantly increased in the diet group, aerobic exercise and diet group, and aerobic exercise with electromyostimulation and diet group (p < 0.05). Short physical performance battery, 6-min walking distance, and flow-mediated dilation significantly increased in the aerobic exercise and diet group and aerobic exercise with electromyostimulation and diet group (p < 0.05). Blood pressure and pulse wave velocity did not differ between interventions. High-density lipoprotein-cholesterol levels significantly increased after 8 weeks in all intervention groups (p < 0.05). There were no significant differences in glucose, HbA1c, total cholesterol, low-density lipoprotein-cholesterol, triglyceride, insulin, Homeostatic Model Assessment for Insulin Resistance, nitric oxide, and C-reactive protein levels. Conclusion: These results show that multi-component interventions appear to improve physical fitness and vascular function in pre-frail older women. Thus, possible strategies to prevent early frailty including proper nutrition and exercise may be needed.

New Trend of Physical Activity and Exercise for Health Promotion and Functional Ability.

Regular physical activity and exercise can improve your health and reduce your risk of developing various diseases including type 2 diabetes, cardiovascular disease, and cancer [...].

Relationship between physiological tremor and cognitive function in physically active older women.

PURPOSE: This study aimed to compare the physiological tremor, grip strength, and cognitive function of sedentary and physically active older adults. METHODS: Twenty-four older adults aged ≥65 years participated in this study and were divided into the sedentary (76.5±4.4 years, n=12) and physically active (73.5±3.3 years, n=12) groups. Each group completed the Mini-Mental State Examination (MMSE) for cognitive function assessment. Physiological tremor was measured using an accelerometer for both hands at rest and the left/right hand with a 1,000 g dumbbell on the palm in neutral positions and the elbow flexed at 90°. Physical fitness was measured by grip strength and completion of the Short Physical Performance Battery (SPPB) and the 6-min walk test. RESULTS: The physically active group showed a significantly lower level of physiological tremor in both hands at rest and the left/right hand with a 1,000 g dumbbell on the palm (P<0.05) than that in the sedentary group. For cognitive function, the physically active group showed significantly higher scores than those in the sedentary group (P<0.001). No significant correlation was found between cognitive function and left/right grip strength (left: r = 0.117, P = 0.585; right: r = 0.230, P = 0.279), physiological tremor in both hands at rest (left: r = -0.524, P < 0.001; right: r = -0.508, P < 0.05), and the left/right hand with a 1,000 g dumbbell on the palm (left: r = -0.505, P < 0.05; right: r = -0.458, P < 0.05). CONCLUSION: Physiological tremor of the hands has the potential to be a useful predictor of cognitive function in older adults.

Effect of Low-Intensity Aerobic Training Combined with Blood Flow Restriction on Body Composition, Physical Fitness, and Vascular Responses in Recreational Runners.

This study investigated the effect of low-intensity aerobic training combined with blood flow restriction (LABFR) on body composition, physical fitness, and vascular functions in recreational runners. The participants were 30 healthy male recreational runners, randomized between the LABFR (n = 15) and control (n = 15) groups. The LABFR group performed five sets of a repeated pattern of 2 min running at 40% VO2max and 1 min passive rest, while wearing the occlusion cuff belts on the proximal end of the thigh. The frequency was three times a week for the period of eight weeks. The control group performed the identical running protocol without wearing the occlusion cuff belts. At the end of the training, the participants' body composition (fat mass, body fat, muscle mass, and right and left thigh circumference), physical fitness (power and VO2max), and vascular responses (flow-mediated dilation (FMD), brachial ankle pulse wave velocity (baPWV), ankle brachial index (ABI), systolic blood pressure (SBP) and diastolic blood pressure (DBP)) were measured. The results showed a significant time × group interaction effect on muscle mass (F = 53.242, p = 0.001, ηp2 = 0.664) and right thigh circumference (F = 4.544, p = 0.042, ηp2 = 0.144), but no significant variation in any other factors, including fat mass, body fat, left thigh circumference, FMD, baPWV, ABI, SBP, and DBP (p > 0.05). Overall, our results suggested that eight-week LABFR exerted a positive effect on the body composition, especially muscle mass and thigh circumference, of recreational runners.

Analysis of physiological tremors during different intensities of armcurl exercises using wearable three-axis accelerometers in healthy young men: a pilot study.

PURPOSE: The purpose of this pilot study was to determine whether physiological tremors (PTs) assessed using an accelerometer could be used to evaluate resistance exercise intensity. METHODS: Twenty healthy young men with no prior experience of resistance exercise were recruited. Different intensities (resting, 30%, 50%, and 70% of their predetermined one-repetition maximum (1-RM)) of arm-curl exercise were used to elicit PT. The total work was held equally by varying the number of repetitions, with five sets for each intensity. Sessions of varying intensities were performed randomly with a washout period of at least a week. PT responses were recorded during exercise using accelerometers (3-axis) attached to the wrist and ear. Electromyography (EMG) data were obtained from the biceps brachii muscle during exercise. PT and EMG data were expressed as the average root mean square index. RESULTS: The EMG amplitude increased significantly as exercise intensity increased. Furthermore, PT amplitude significantly increased as exercise intensity increased. Moreover, the Borg rating of perceived exertion (RPE) and lactic acid levels increased significantly. The wrist PT was related to ear PT, EMG, RPE, and lactic acid levels. Additionally, ear PT was associated with EMG, RPE, and lactic acid levels. CONCLUSION: This pilot study identified changes in PT during resistance exercise at different intensities. We suggest that the use of PT analyses during these exercises provides a more intuitive delineation of resistance exercise intensity and fatigue.

The effect of short-term creatine intake on blood lactic acid and muscle fatigue measured by accelerometer-based tremor response to acute resistance exercise.

PURPOSE: The purpose of this study was to investigate the effects of short-term creatine intake on muscle fatigue induced by resistance exercise in healthy adolescent men, i.e., lactic acid concentration and wrist and head tremor measured by an accelerometer. METHODS: Twelve healthy adolescent men who had no experience with creatine intake were included. The subjects were randomly assigned to the creatine group and the placebo group, followed by 5 days of creatine and placebo intake, and 5 times of 5 sets of leg press, leg extension, bench press, and arm curl exercises at 70% repetition maximum (RM). The lactic acid concentration before and after exercising, rate of perceived exertion (RPE), and accelerometer-based wrist tremor and head tremor during exercise were measured. Subsequently, after 7 days to allow for creatine washout, the same exercise treatment and measurement were performed in each group after switching drug and placebo between the groups. RESULTS: The level of lactic acid before and after the acute resistance exercise trial was significantly lower in the creatine group than in the placebo group (P <0.05). The mean RPE during the resistance exercise was significantly lower in the creatine group than in the placebo group (P <0.05). There was no difference between the two groups in the mean wrist tremor during resistance exercise, but the mean head tremor values were significantly lower in the creatine group than in the placebo group in the arm curl, the last event of the exercise trials (P <0.05). CONCLUSION: Short-term creatine intake reduces the blood fatigue factor increased by resistance exercise, and is thought to suppress fatigue, especially in the latter half of resistance exercise. Therefore, these findings indicate that short-term creatine intake can have an improved effect on anaerobic exercise performance.

The effect of oral glucose tolerance testing on changes in arterial stiffness and blood pressure in elderly women with hypertension and relationships between the stage of diabetes and physical fitness levels.

PURPOSE: The purpose of this study was to assess changes in blood glucose level, blood pressure, and arterial stiffness after a 75 g oral glucose tolerance test (OGTT) in elderly women aged over 65 years with hypertension and either normal glycemic control, impaired fasting glucose tolerance, or diabetes mellitus. We also wished to investigate the relationship between stages of diabetes and physical fitness. METHODS: A total of 24 elderly women with hypertension were assigned to a control group (CON; n=7), impaired fasting glucose group (IFG; n=9), and diabetes mellitus group (DM; n=8). In each group, blood glucose level, brachial ankle pulse wave velocity (PWV), and blood pressure were measured at baseline as well as 60 and 120 minutes after a 75 g OGTT. Physical fitness factors such as hand grip strength, balance test, 4 m gait speed test, chair stand test, short physical performance battery, and 6-minute walking test were subsequently assessed. RESULTS: In all three groups, blood glucose levels were significantly increased at 60 and 120 minutes after a 75 g OGTT. In the DM group, blood glucose levels were significantly higher before and after a 75 g OGTT than in the CON group. In the CON group, PWV was significantly increased at 60 minutes after a 75 g OGTT; however, there were no changes in other groups after glucose ingestion. In the CON group, systolic and diastolic blood pressures were significantly decreased at 60 and 120 minutes after a 75 g OGTT compared to baseline. However, there was no change in blood pressure after ingestion in the DM group. The IFG group had greater grip strength than the CON group; however, there were no differences in other variables between the groups. CONCLUSION: After a 75 g OGTT, elderly women with hypertension and diabetes maintain higher blood glucose levels compared to those with hypertension alone. Unlike elderly women with hypertension alone, those with hypertension and diabetes did not show changes in arterial stiffness and blood pressure after a 75 g OGTT. Therefore, elderly women with hypertension and diabetes may not be able to control their blood vessels following a 75 g OGTT due to impaired vascular endothelial function. Moreover, there was no association between diabetes stage and physical fitness in elderly women with hypertension.

Effects of Moderate Combined Resistance- and Aerobic-Exercise for 12 Weeks on Body Composition, Cardiometabolic Risk Factors, Blood Pressure, Arterial Stiffness, and Physical Functions, among Obese Older Men: A Pilot Study.

We demonstrated the hypothesis that combined exercise improves body composition, cardiometabolic risk factors, blood pressure (BP), arterial stiffness, and physical functions, in obese older men. Older men (n = 20) were randomly assigned to combined exercise training (EXP; n = 10) or control groups (CON; n = 10). The combined exercise was comprised of elastic-band resistance training and walking/running on a treadmill and bicycle at 60-70% of maximal heart rate for 3 days/weeks. EXP showed significant decreases in body weight, body mass index, and %body fat (p < 0.05). The exercise program significantly reduced BP, mean arterial pressure, pulse pressure, and brachial-ankle pulse wave velocity. Furthermore, while the plasma levels of low-density lipoprotein cholesterol and epinephrine were significantly reduced in EXP, VO2 peak and grip strength were significantly enhanced (p < 0.05). In conclusion, it is indicated that 12-week regular combined exercise improves body composition, cardiometabolic risk factors, hemodynamics, and physical performance in obese older men.

Analyses of physiological wrist tremor with increased muscle activity during bench press exercise.

PURPOSE: To date, there have been no studies on the response of wrist tremor to increased muscle activity during exercise. This study aimed to evaluate the wrist tremor response with increasing muscle activity during bench press exercise. METHODS: Triceps muscle activity and wrist tremor response were measured by electromyography and an accelerometer, respectively, during bench press exercise in 11 healthy men without weight-training experience. Subjects performed bench press at 30% repetition maximum (RM), and the rating of perceived exertion (RPE) and lactate concentration were measured before and after exercise. One week later, an equivalent number of bench presses at 30% RM was performed without weight load as a control trial (CT). RESULTS: RPEs and lactate concentrations significantly increased after resistance exercise (30% RM) from 7.4 to 14.3 and 1.7 to 4.9, respectively (P<.01), but no such difference was observed in the CT. Muscle activity linearly increased during the 30% RM exercise, and wrist tremors were shown to linearly decrease. A strong negative correlation was observed between the two variables (r=-0.88, P<.001). CONCLUSION: We found that wrist tremors during resistance exercise, as measured using an accelerometer, can be used to predict muscle activity.

Twelve Weeks of Combined Resistance and Aerobic Exercise Improves Cardiometabolic Biomarkers and Enhances Red Blood Cell Hemorheological Function in Obese Older Men: A Randomized Controlled Trial.

The present study examined the effect of a 12-week combined resistance and aerobic exercise training program on cardiometabolic biomarkers and red blood cell (RBC) hemorheological function in 20 obese older men (mean age: 68.8 ± 0.9 years). Subjects were randomly divided into two groups (exercise intervention [EXP; n = 10] and control [CON; n = 10]). The EXP subjects performed resistance and aerobic exercise training program three times per week for 12 weeks, and the CON subjects maintained their regular lifestyle during the intervention period. Body composition was estimated using bioelectrical impedance analysis equipment. Cardiometabolic biomarkers (glucose, insulin, homeostasis model assessment-estimated insulin resistance (HOMA-IR), HOMA ß-cell function, and leptin) and RBC hemorheological parameters (RBC deformability and aggregation) were analyzed. Percent body fat decreased significantly in the EXP group during the intervention period but increased significantly in the CON group. Insulin increased significantly in the CON group over the 12-week period and both insulin and HOMA-IR were significantly higher in the CON group than in the EXP group at post-test. RBC deformability (RBC EI_3Pa) and aggregation (RBC AI_3Pa) improved significantly only in the EXP group. The present study suggests that combined exercise training can be useful for improving cardiometabolic biomarkers and RBC hemorheological parameters in obese older men and may help prevent metabolic syndrome and cardiovascular diseases.

The association of locomotive and non-locomotive physical activity measured by an accelerometer with functional fitness in healthy elderly men: a pilot study.

PURPOSE: The purpose of this study was to investigate the relationship of various aspects of daily physical activity, such as the number of steps, time spent in moderate to vigorous intensity physical activity (MVPA), and locomotive and non-locomotive MVPA measured by a triaxial accelerometer, with the functional fitness in healthy elderly men. METHODS: The subjects of this study were 22 healthy elderly men aged over 65 years. The participants wore a triaxial accelerometer for two weeks to estimate their daily physical activities. The level of functional fitness was measured based on "National Fitness Award 100 in Korea" immediately after the measurement of two weeks of daily physical activities. RESULTS: The results showed that active healthy elderly men with more than 6,500 walking steps per day and more than 60 min per day spent in MVPA showed a significantly higher 2-min marching in place and index of cardiorespiratory endurance compared to less physically active participants. Particularly, locomotive MVPA was significantly associated with cardiorespiratory endurance levels (r = 0.50), whereas non-locomotive MVPA was not associated with other measurements of functional fitness. CONCLUSION: Increased MVPA time, especially the locomotive MVPA, can effectively suppress the decrease in cardiorespiratory endurance level in elderly men. However, no association was observed between non-locomotive MVPA, such as household activities, and functional fitness in healthy elderly men.

Nonfat milk attenuates acute hyperglycemia in individuals with android obesity: A randomized control trial.

BACKGROUND: Elevated android body fat increases the risk of developing cardiometabolic diseases. Postprandial hyperglycemia contributes to the proatherogenic metabolic state evident in android adiposity. Due to the insulinotropic effect of milk-derived proteins, postprandial hyperglycemia has been shown to be reduced with the addition of dairy products. The purpose of this study was to determine whether one serving of nonfat milk added to an oral glucose tolerance test (OGTT) could attenuate postprandial hyperglycemia in individuals with elevated android adiposity and whether these improvements would be associated with metabolic and/or peripheral hemodynamic effects. METHODS: In this placebo-controlled, randomized, crossover experimental study, 29 overweight/obese adults (26 ± 1 year) consumed an OGTT beverage (75 g glucose) combined with either nonfat milk (227 g) or a placebo control (12 g lactose + 8 g protein + 207 g water) that was matched for both carbohydrate and protein quantities. RESULTS: In the whole sample, blood glucose and insulin concentrations increased over time in both trials with no significant differences between trials. Relative increases in peak blood glucose response were significantly related to android body fat (p < 0.05). The subjects in the highest tertiles of android body fat displayed attenuated hyperglycemic responses as well as improvements in flow-mediated dilation (FMD) after milk intake. CONCLUSIONS: A single serving of nonfat milk may attenuate acute hyperglycemia in individuals with elevated android body fat offering a simple and convenient option for managing elevations in blood glucose.