Impact of placement of fitbit HR under laboratory and free-living conditions

© 2020 by the authors. Wrist-worn activity monitors have become accessible for measuring physical activities, but an activity monitor\u27s accuracy worn at different placements is not well understood. This study aimed to examine the differences in measurements of heart rates, step counts, and calories estimated from the fitness tracker worn at different locations and the accuracy of Fitbit HR against criterion measures. Thirty-two healthy adults participated in this study. Participants wore Fitbit HR at four different locations (right proximal, distal, and left proximal, distal). Treadmill exercise consisted of five 5-min phases including slow walking and jogging. Free-living activities involved ten 5-min activities with four different intensities. We found that the placement of Fitbit HR has no significant influence on the measurement outcomes overall. However, significant differences were observed in the step counts between left and right while climbing stairs (p = 0.003) and sports activities (p \u3c 0.001). The accuracy of Fitbit HR measurements against the criterion measure was moderate. However, we found out that Fitbit HR overestimated the calories regardless of their positions and activity types. In conclusion, the different placements of Fitbit HR do not have a significant influence on the measurements and Fitbit HR was moderately associated with criterion reference devices for measures of heart rate and steps

Effect of Exercise Intervention on Flow-Mediated Dilation in Overweight and Obese Adults: Meta-Analysis

The objective of this meta-analysis is to summarize the effect of exercise intervention on flow-mediated dilatation (FMD) in overweight and obese adults. We searched four electronic databases (PubMed/Medline, Scopus, and CINAHL) through June 2016 for relevant studies pertaining to the effectiveness of exercise intervention on FMD. Seventeen of the 91 studies identified met the inclusion criteria. Comprehensive Meta-Analysis software (version 3) was used to compute the standardized mean difference effect size (ES) and 95% CI using a random effects model. We calculated 34 ESs. We found that exercise intervention had medium and positive effects on FMD, with an overall ES of 0.522 (95% CI = 0.257, 0.786). Heterogeneity of ESs was observed ( = 239, ≤ 0.001, 2 = 86.19), and the effect was moderated by comorbidity ( = 6.39, df = 1, = 0.011). A large ES for the combination exercise, low intensity exercise, and comorbidity subgroups (ES = 0.82∼1.24) was found. We conclude that while exercise intervention significantly improves FMD in overweight and obese adults, the effect may depend on the different characteristics of exercise intervention and on participants’ demographics

Optimal Frequency Intensity of Physical Activity to Reduce the Risk of Hypertension in the Korean Population

PURPOSE: Regular physical activity (PA) is an effective lifestyle modification for preventing hypertension. This study aimed to analyze the optimal frequency of PA required to reduce the incidence of hypertension in the Korean population. Most Korean studies have included only small samples and limited age ranges. METHODS: The present study analyzed 16,299,865 participants aged ≥20 years (44.25±12.74 years) from the 2009 to 2012 Korean National Health Insurance Corporation Survey database. The International Physical Activity Questionnaire was used to assess the frequency and intensity of physical activity. Hazard ratios for incident hypertension were analyzed by physical activity participation, age, and sex using multivariable Cox proportional hazard models, with a non-regular physical activity group as reference. RESULTS: A total of 1,322,674 cases of incident hypertension were identified during the mean follow-up period of over 3 years. Hazard ratios for incident hypertension increased with age, with values of 50.4 and 56.1 for men and women in the older age group, respectively. Hazard ratios for incident hypertension were significantly lower in the regular PA group of middle-aged (4%) and older (7%) adults than in the non-regular PA group. The study revealed that moderate-to-vigorous-intensity PA 3-5 times/week was most effective in reducing the risk of incident hypertension in middle-aged and older adults but not in young adults. We observed no additional lowering of incident hypertension risk in the group undergoing moderate-to-vigorous PA at a frequency of 6-7 days/week compared to the 35 days/week group. CONCLUSIONS: We suggest PA at a frequency of 3-5 times/week for the prevention of incident hypertension in Korean adults

The Acute and Chronic Effect of Korea Ginseng Supplement on Exercise Performance, Cognitive Function, and Fatigue Recovery

The purpose of this study was to determine the acute and chronic effects of Korean ginseng supplements on exercise performance, cognitive function, and fatigue recovery. The study used double-blind, placebo-controlled, crossover design. Twelve healthy adult males (age = 31 ± 6.86 yrs) were randomly assigned to either KGD or placebo trials. All subjects conducted the exercise consisted with 30 minutes cycling at 70-75% of VO2 max followed by 16 km time trial with 30 minutes resting periods. All subjects were tested for muscular power, strength, endurance, cognitive function, and fatigue. The subjects took KGD (280 ml containing 5.88 mg of ginsenosides) or placebo 90 mins before exercise trials and following 7 days. The blood sample was drawn for IL-6, myoglobin, and total antioxidant capacity immediately after time trial, as well as 2, 24, 48, and 72 hours. After 2 weeks of wash-out period, the subjects were crossed over into the opposite trial and performed the same test. Repeated measures ANOVAs were used to examine the effect of acute and chronic intake of ginseng on exercise performance and blood variables. An alpha of .05 was used, and the Greenhouse-Geisser (G-G) adjusted F and degrees of freedom were reported. In a placebo trial, peak power and mean power levels were significantly decreased across time, F (1.47, 13.24) = 4.63, G-G p = .039, h2p = .340 and F (1.46, 13.13) = 5.31, G-G p = .028, h2p = .371 while no differences were found in a ginseng trial. In a placebo trial, average reaction time (ART) was significantly increased across time, F (1.29, 11.63) = 10.81, G-G p = .005, h2p = .546, but in a ginseng trial, no difference in ART was found across time, F (1.54, 13.86) = 4.02, G-G p = .051, h2p = .309. There was a significant increase in TAC across time in a ginseng trial, F (1.42, 11.37) = 5.07, G-G p = .035, h2p = .388 while no difference was found in a placebo trial. No significant differences were found in other variables from placebo and ginseng trails. The 7 days of KRG supplementation significantly reduced the serum myoglobin concentration across time in the KGD trial, F (1.88, 13.17) = 5.18, G-G p = .023, while no difference was found in the placebo trial, F (2.21, 17.66) = .88, G-G p = .443. No significant differences were observed in serum total antioxidant activity and IL-6 between KGD and placebo trials. The study shows that Korean ginseng supplement before stating the exercise improve anaerobic capacity, cognitive function in particular psychomotor vigilance task, and fatigue recovery during cycling exercise. And 7 days of Korean ginseng supplement reduces muscle damage and fatigue after cycling exercise

Exercise Training Attenuates Ovariectomy-Induced Alterations in Skeletal Muscle Remodeling, Apoptotic Signaling, and Atrophy Signaling in Rat Skeletal Muscle

Purpose The effects of aerobic exercise training on soleus muscle morphology, mitochondria-mediated apoptotic signaling, and atrophy/hypertrophy signaling in ovariectomized rat skeletal muscle were investigated. Methods Female Sprague-Dawley rats were divided into control (CON), ovariectomy (OVX), and ovariectomy plus exercise (OVX+EX) groups. After ovarian excision, exercise training was performed using a rat treadmill at 20 m/min, 50 min/day, 5 days/week for 12 weeks. Protein levels of mitochondria-mediated apoptotic signaling and atrophy/hypertrophy signaling in the skeletal muscle (soleus) were examined through western immunoblot analysis. Results The number of myocytes and myocyte cross-sectional area (CSA) were increased and the extramyocyte space was decreased in the OVX group compared to those in the CON group. However, aerobic exercise training significantly increased myocyte CSA and decreased extramyocyte space in the OVX+EX group compared to those in the OVX group. The protein levels of proapoptotic signaling and muscle atrophy signaling were significantly increased, whereas the protein levels of muscle hypertrophy signaling were significantly decreased in the OVX group compared to that in the CON group. Aerobic exercise training significantly decreased the protein levels of proapoptotic signaling and increased the protein level of antiapoptotic protein in the OVX+EX group compared to that in the OVX group. Aerobic exercise training significantly increased the protein levels of hypertrophy signaling and decreased protein levels of atrophy signaling in the OVX+EX group compared to those in the OVX group. Conclusions Treadmill exercise improved estrogen deficiency-induced impairment in skeletal muscle remodeling, mitochondria-mediated apoptotic signaling, and atrophy/hypertrophy signaling in skeletal muscle

The corrective nonlinear simplex search algorithm and its application to the refinement problems of crystal structures

Vita.This dissertation is concerned with the following unconstrained optimization problem: [See PFD for equation]. This problem is known as the refinement problem of crystal structures. Previous contributions of optimization methodology to the direct solution of crystal structures have made use of the phase relationships in the measured structure factors. This dissertation describes the application of a direct approach to the refinement problem of crystal structures using a nonlinear optimization methodology. The first part of this dissertation is concerned with the development of the corrective nonlinear simplex search technique. After investigating several nonlinear search techniques as applied to the refinement problem, we added a new feature to the nonlinear simplex algorithm which resulted in a more nearly optimal solution of the refinement problem. This algorithm, which is named the corrective nonlinear simplex search (CNSS) method, consists of two basic steps: 1. Search for the direction of each variable by an exploratory search method, 2. Then, search for the optimal positions by the flexible polygon search technique which requires four operations: reflection, expansion, contraction, and reduction.

The corrective nonlinear simplex search algorithm and its application to the refinement problems of crystal structures

Vita.This dissertation is concerned with the following unconstrained optimization problem: [See PFD for equation]. This problem is known as the refinement problem of crystal structures. Previous contributions of optimization methodology to the direct solution of crystal structures have made use of the phase relationships in the measured structure factors. This dissertation describes the application of a direct approach to the refinement problem of crystal structures using a nonlinear optimization methodology. The first part of this dissertation is concerned with the development of the corrective nonlinear simplex search technique. After investigating several nonlinear search techniques as applied to the refinement problem, we added a new feature to the nonlinear simplex algorithm which resulted in a more nearly optimal solution of the refinement problem. This algorithm, which is named the corrective nonlinear simplex search (CNSS) method, consists of two basic steps: 1. Search for the direction of each variable by an exploratory search method, 2. Then, search for the optimal positions by the flexible polygon search technique which requires four operations: reflection, expansion, contraction, and reduction.

The (S-1, S) Inventory Model with Order Size Dependent Delivery Times

This paper considers (S-1, S) inventory models which have wide applications in reparable spare parts inventory systems and multi-echelon systems. We assume a discrete compound Poisson demand and order size dependent delivery times: when the replenishment order size is n, we assume the delivery time distribution is arbitrary with finite mean b. On the basis of the fact the outstanding orders follow a certain queueing process, we introduce the results of Fakinos (1982). We develop the efficient recursive formulae to find the optimal S under several performance measures as a function of the decision variable S. The results of this paper can be applied to the multi-echelon systems such as METRIC

Refreshing Distributed Multiple View and Replicas

In this paper we prescribe a replication server scheme with an algorithm DRF (Differential Refresh File) to refresh multiple materialized views and replicas in distributed environments. Before sending relevant tuples in server sites to client sites, an effective tuple reduction scheme is developed as a preprocessor to reduce the transmission cost. Because it utilizes differential files without touching base relations, the DRF scheme can help to minimize the number of lucks, which enhances the system's performance