Differences in salient beliefs associated with voluntary exercise training among South Korean firefighters before and after COVID-19.

BACKGROUND: Participating in voluntary exercise training is important to meet occupational requirements as well as firefighters' health and safety. The purpose of this study is to identify salient beliefs associated with voluntary exercise training among firefighters in the pandemic era by comparing outcomes with those from a previous elicitation study, which was carried out before the COVID-19 outbreak. METHODS: A total of 57 firefighters are recruited to participate in an elicitation study. Participants are requested to respond to six open-ended questions related to voluntary exercise training. Content analysis is used to create categories that combine similar factors in each belief. Beliefs mentioned by more than 30% of participants are used for comparison with the results of the previous research. RESULTS: "Improves my physical ability" (n = 44) and "cause injury" (n = 17) are identified as behavioral beliefs in the present study, whereas "makes me tired" and "takes too much time" were also elicited in Lee's study. Normative beliefs are "family members" (n = 45) and "colleagues" (n = 27) and these results are consistent with those in Lee's study. "Lack of time" (n = 28), "exercise facilities" (n = 19), and "COVID-19" (n = 19) are elicited as control beliefs in the present study, whereas "physical condition" (n = 21) and "exercise partners" (n = 14) were elicited as other control beliefs, and "COVID-19" was not mentioned in Lee's study. CONCLUSION: This study can contribute valuable information about salient beliefs associated with exercise training behavior among firefighters, particularly under pandemic conditions. Future researchers should develop tailored exercise training programs for firefighters based on current elicited beliefs.

Comparative Effects of Vigorous-Intensity and Low-Intensity Blood Flow Restricted Cycle Training and Detraining on Muscle Mass, Strength, and Aerobic Capacity.

Traditional high-intensity aerobic training has been shown to improve muscle protein synthesis and aerobic capacity; however, recent research indicates that low-intensity aerobic training with blood flow restriction (BFR) may have similar effects. The purpose of this study was to compare the effects of vigorous-intensity (VI) cycling vs. low-intensity cycling with BFR (LI-BFR) on muscle mass, strength, and aerobic capacity after training and subsequent detraining. Thirty-one physically active subjects were assigned to one of 3 groups: VI (n = 10, 60-70% heart rate reserve [HRR]), LI-BFR (n = 11, 30% HRR with BFR at 160-180 mm Hg), and no exercise control (n = 10, no exercise). Subjects in VI and LI-BFR cycled 3 times per week for 6 weeks (total 18 sessions). Body composition, muscle mass, strength, and aerobic capacity were measured pre, post, and after 3 weeks of detraining. A group × time interaction (p = 0.019) effect for both knee flexion and leg lean mass was found. For both VI and LI-BFR groups, knee flexion strength was significantly increased between pre and post (p = 0.024, p = 0.01) and between pre and 3 week-post (p = 0.039, p = 0.003), respectively. For the LI-BFR group, leg lean mass was significantly increased between pre and 3 week-post (p = 0.024) and between post and 3 week-post (p = 0.013). However, there were no significant differences between groups for any variables. The LI-BFR elicits an increase in the knee flexion muscle strength over time similar to the VI. An increase in the leg lean mass over time was seen in the LI-BFR, but not in VI and CON.

Three-dimensional augmentation for hyperspectral image data of water quality: An Integrated approach using machine learning and numerical models.

This research introduces a comprehensive methodology to enhance hyperspectral image data (HSD) utility, specifically focusing on the three-dimensional (3-D) augmentation of Chlorophyll-a (Chl-a). This study comprises three significant steps: (1) the augmentation of limited field water quality data in terms of time interval and number of variables using neural network models, (2) the generation of 3-D data using numerical models, and (3) the extension of the hyperspectral image data into 3-D data using machine learning models. In the first phase, Multilayer Perceptron (MLP) models were developed to train water quality interactions and successfully generated high-frequency water quality data by adjusting biased measurements and predicting detailed water quality variables. In the second phase, high-frequency data generated by MLP models were applied to develop two numerical models. These numerical models successfully generated 3-D data, thereby demonstrating the effectiveness of integrating numerical modeling with neural networks. In the final phase, ten machine learning models were trained to generate 3-D Chl-a data from HSD. Notably, the Gaussian Process Regression model exhibited superior performance, effectively estimating 3-D Chl-a data with robust accuracy, as evidenced by an R-square value of 0.99. The findings align with theories of algal bloom dynamics, further validating the effectiveness of the approach. This study demonstrated the successful integrated development for HSD extension using machine learning models, numerical models, and original HSD, highlighting the potential of such integrated methodologies in advancing water quality monitoring and estimation. Notably, the approach leverages readily accessible data, allowing for the swift generation of results and bypassing time-consuming data collection processes. This research marks a significant step towards more robust, comprehensive water quality monitoring and prediction, thereby facilitating better management of aquatic ecosystems.

Improving Cardiorespiratory and Muscular Function of Korean Firefighters: A Kinect-Based Mixed Reality Device Exercise Intervention Randomized Control Trial.

OBJECTIVE: This study addresses declining physical fitness among Korean firefighters due to a low exercise participation rate caused by the absence of exercise instructors. The research explores Virtual Mate (VM), a Kinect-based mixed reality device, as a potential solution, but its capacity to replace training instructors in enhancing physical fitness remains uncertain. METHODS: Twenty Korean male firefighters were divided into two groups: the exercise group received an 8-week intervention using VM, while the control group maintained regular physical activity. Cardiopulmonary function and muscle function were measured. RESULTS: After 8 weeks, the exercise group demonstrated a significant improvement in VO 2peak . Furthermore, there were notable enhancements in the strength and endurance of most knee, shoulder, and trunk flexors and extensors. CONCLUSIONS: Integrating VM into an exercise program can effectively improve cardiorespiratory and muscular function in Korean firefighters.

Comparing the effects of 3 weeks of upper-body vibration training, vibration and stretching, and stretching alone on shoulder flexibility in college-aged men.

This study compared the effects of 3 weeks of upper-body vibration training, vibration and stretching, and stretching alone on shoulder flexibility in college-aged men. Twenty-one men were randomly assigned to vibration-stretching (VS; n = 8), vibration only (VO; n = 6), or stretching only (SO; n = 7) groups that trained 3 times per week for 3 weeks. All 3 groups performed 9 total sets of 30-second stretches. The VS group performed four 30-second upper-body vibration exercises and five 30-second upper-body stretching exercises. The VO group performed nine 30-second upper-body vibration exercises. The SO group performed nine 30-second upper-body stretching exercises. Shoulder flexion (SF), shoulder extension (SE), and shoulder transverse extension (STE) were assessed by a Leighton Flexometer and back scratch tests bilaterally (BSR, BSL) were measured via tape measure. A 1-way analysis of variance (ANOVA) evaluated groups at baseline and a 2-way repeated-measures ANOVA evaluated the interventions over time. At baseline, there were no group differences in age, height, or weight. There was a significant (p < 0.01) time main effect for each flexibility outcome variable (SF: +6.1%, +3.9%, +3.4%; SE: +8.9%, +13.5%, +26.9%; STE: +12.8%, +8.7%, +24.3%; BSR: +4.4 cm, +3.4 cm, +3.1 cm; BSL: +3.6 cm, +2.3 cm, +6.1 cm) for SO, VO, and VS, respectively. Shoulder extension was the only variable that showed a significant (p < 0.05) interaction effect for group by time. In conclusion, vibration training, alone or combined with stretching, is a viable alternative to a standard stretching routine when attempting to increase shoulder flexibility. Adding vibration training to a flexibility regimen may improve the likelihood of regularly performing flexibility sessions because of increased variety.

Identification of pollutant sources and evaluation of water quality improvement alternatives of a large river.

While pollutants are the most important factors for the deterioration of surface water quality, the identification of major pollutant sources for rivers is challenging, especially in areas with diverse land covers and multiple pollutant inputs. This study aims to identify the significant pollutant sources from the tributaries that are affecting the water quality and identify the limiting nutrient for algal growth in the Geum river to provide a management alternative for an improvement of the water quality. The positive matrix factorization (PMF) was applied for pollutant source identification and apportionment of the two major tributaries, Gab-cheon and Miho-cheon. Positive matrix factorization identifies three and two major pollutant sources for Gab-cheon and Miho-cheon, respectively. For Gab-cheon, wastewater treatment plants, urban, and agricultural pollution are identified as major pollutant sources. Furthermore, for Miho-cheon, agricultural and urban pollution were identified as major pollutant sources. Total phosphorus (TP) is also identified as a limiting nutrient for algal growth in the Geum river. Water quality control scenarios were formulated and improvement of water quality in the river locations was simulated and analyzed with the Environmental Fluid Dynamic Code (EFDC). Scenario results were evaluated using a water quality index. The reduction of total phosphorus (TP) from the tributaries has greatly improved the water quality, especially algal bloom in the downstream stations.

Ultra-weak photon emission during wrist curl and cycling exercises in trained healthy men.

Human ultra-weak photon emission (UPE) is related to the activity of respiratory chain and oxygen consumption. Investigations on UPE and its response to exercise are almost non existent. Since human UPE is an indicator of reactive oxygen species (ROS) levels, we used exercises as a model to study UPE. To continue the research on the relationship between human UPE and exercise, it was decided to carry out measurements of UPE in response to different exercise modes with 20 healthy male subjects. The performed exercises were wrist curls with a dumbbell and indoor cycling. Regarding wrist curl exercises, 70% of the subjects for the first exercise and 65% for the second exercise did not show any significant changes in UPE. Also, the statistical analysis did not show significant changes of the UPE levels. In terms of cycling exercise, 85% of subjects did not show any significant increase of UPE. The gathered data showed that a majority of the subjects didn't show an increase of the UPE during both types of exercises. Our results imply that the UPE is not only affected by oxygen consumption, but also by the intensity, the type of exercise, and the physiology of the subject.

Reliability of the one-repetition maximum test based on muscle group and gender.

The purpose of the present study was to examine the influence of muscle group location and gender on the reliability of assessing the one-repetition maximum (1RM) test. Thirty healthy males (n = 15) and females (n = 15) who experienced at least 3 months of continuous resistance training during the last 2 years aged 18-35 years volunteered to participate in the study. The 1RM for the biceps curl, lat pull down, bench press, leg curl, hip flexion, triceps extension, shoulder press, low row, leg extension, hip extension, leg press and squat were measured twice by a trained professional using a standard published protocol. Biceps curl, lat pull down, bench press, leg curl, hip flexion, and squat 1RM's were measured on the first visit, then 48 hours later, subjects returned for their second visit. During their second visit, 1RM of triceps extension, shoulder press, low row, leg extension, hip extension, and leg press were measured. One week from the second visit, participants completed the 1 RM testing as previously done during the first and second visits. The third and fourth visits were separated by 48 hours as well. All four visits to the laboratory were at the same time of day. A high intraclass correlation coefficient (ICC > 0.91) was found for all exercises, independent of gender and muscle group size or location, however there was a significant interaction for muscle group location (upper body vs. lower body) in females (p < 0.027). In conclusion, a standardized 1RM testing protocol with a short warm-up and familiarization period is a reliable measurement to assess muscle strength changes regardless of muscle group location or gender. Key pointsThe one repetition maximum (1RM) test is considered the gold standard for assessing muscle strength in non-laboratory situations.This study was done to examine the influence of muscle group location and gender on the reliability of assessing the 1RM test.The standardized 1RM testing protocol with a short warm-up and familiarization period is a reliable measurement technique to assess muscle strength changes regardless of muscle group location or gender.

Changes in Physical Fitness among Elementary and Middle School Students in Korea before and after COVID-19.

The present study aimed to analyze changes in health-related physical fitness among Korean elementary and middle school students before (2019) and after (2021) the COVID-19 pandemic. Data collection was completed by requesting the physical activity promotion system (PAPS) data from elementary and middle school students. This information is obtained annually by the Goyang Office of Education in Gyeonggi-do, Korea. The collected data were measured in 2019 and 2021. Data were collected from 17,000 children in the fifth and sixth grades of elementary school and about 24,000 boys and girls in the first, second, and third grades of middle school. Chi-square analyses were used to examine data from each school's health-related physical fitness examinations. Our results indicated that physical fitness levels were significantly lower in 2021 than in 2019 across the following six areas: cardiorespiratory endurance, power, muscular strength, flexibility, obesity, and overall health-related physical fitness (p < 0.05). In addition, the ratio of students with excellent physical fitness (PAPS Grades 1 and 2) significantly decreased from 2019 to 2021, while the ratio of students with poor physical fitness (PAPS Grades 3, 4, and 5) increased (p < 0.05). In addition, there were some differences according to grade and gender. Discussions regarding the impact of decreases in physical activity on physical fitness, interpretations of physical fitness in the context of a pandemic, and practical measures that can be implemented to improve health and fitness among children and adolescents in such situations remain essential.

Process and Outcome Evaluations of Interventions to Promote Voluntary Exercise Training Among South Korean Firefighters.

The main aim of the present study is to evaluate reach, dose, fidelity, and outcomes of the interventions for promoting voluntary exercise training among South Korean firefighters. Four interventions for promoting voluntary exercise training among firefighters (i.e., virtual reality exercise system intervention, poster intervention, monitor intervention, and wearable health device intervention) were performed in a fire station located in Seoul, South Korea. To evaluate reach and dose received related to each intervention, participants were asked to answer several simple questions. Three process evaluators completed a 20-item survey to share their impressions related to the quality of intervention delivery. Paired t test was used to examine mean changes in primary (i.e., mean minutes of exercise training per week) and secondary outcomes (i.e., beliefs and intention) between pre- and postinterventions. More than 60% of participants experienced monitor and wearable health device interventions. Process evaluators tend not to agree with a statement saying that the number of the virtual reality exercise equipment was appropriate. Among firefighters who participated in exercise training less than 150 min per week at 1-month follow-up, mean minutes of exercise training per week increased by 67.95 min after interventions. Future studies need to examine whether the monitor and wearable health device interventions effectively increase exercise training participation among firefighters in other fire stations located in Seoul, South Korea.

Effect of different types of resistance exercise on arterial compliance and calf blood flow.

Low-intensity blood flow restricted (LI-BFR) resistance training has been shown to produce comparable increases in muscle hypertrophy to traditional high-intensity (HI) resistance training. However, a comparison of the acute vascular responses between the two types of exercise has not been made. The purpose of this study is to compare the acute vascular responses of HI, low-intensity (LI), and LI-BFR resistance exercise. Using a randomized, cross-over design, 11 young (28 ± 5 years) males completed three acute resistance exercise bouts (HI, LI and LI-BFR). Before (Pre), and starting at 15- and 45-min after each exercise bout, large (LAEI) and small (SAEI) artery compliance and calf blood flow were assessed. Calf blood flow was normalized per unit pressure as calf vascular conductance (CVC). Repeated measures (condition × time) ANOVA revealed a main time effect for LAEI and a main condition effect for SAEI. LAEI increased following exercise but returned to baseline at 45-min post. SAEI was greater during the HI condition compared to the LI or LI-BFR conditions. There was a significant condition × time interaction for CVC. CVC was elevated at 15- and 45-min post during the HI condition and at 15-min following the LI condition. CVC was not altered following the LI-BFR condition. These results suggest that HI, LI, and LI-BFR resistance exercise cause similar acute increases in large artery compliance but HI causes greater increases in small artery compliance and calf vascular conductance than LI or LI-BFR resistance exercise.

Effects of 4 weeks of traditional resistance training vs. superslow strength training on early phase adaptations in strength, flexibility, and aerobic capacity in college-aged women.

This study compared SuperSlow resistance training (SRT) to traditional resistance training (TRT) during early phase adaptations in strength, aerobic capacity, and flexibility in college-aged women. Subjects were randomly assigned to SRT (n = 14); TRT (n = 13); or control (CON; n = 8) groups. To equalize training times, TRT trained 3 times per week for 25 minutes each session, whereas SRT trained twice a week for 35 minutes each session. Both groups trained for 4 weeks, whereas the CON group maintained normal daily activities. Workouts consisted of 5 exercises: shoulder press, chest press, leg press, low row, and lat pull down. The SRT group completed 1 set of each exercise at 50% 1RM until momentary failure with a 10-second concentric and a 10-second eccentric phase. The TRT group completed 3 sets of 8 repetitions at 80% 1RM for each exercise, with 4 seconds of contraction time for each repetition. Groups were statistically similar at baseline. There was a significant (p ≤ 0.01) time main effect for flexibility with the greatest improvements occurring for the training groups (SRT 14.7% and TRT 11%). All strength tests had significant (p ≤ 0.01) time main effects but no group or group by time interactions. Both training groups had large percent improvements in strength compared to CON, but the large variability associated with the SRT group resulted in only the TRT group being significantly different from the CON group. In conclusion, percent improvements were similar for the TRT and SRT groups, but only the TRT group reached statistical significance for the strength improvements, and both groups were equally effective for improving flexibility.

Effects of 12 weeks of combined exercise training on visfatin and metabolic syndrome factors in obese middle-aged women.

Visfatin is a highly expressed protein with insulin-like functions located predominantly in visceral adipose tissue and has been linked to obesity and increased health risks. The purpose of this study was to examine the effects of 12 weeks of combined exercise training on visfatin and metabolic syndrome factors in obese middle-aged women. Subjects were randomly assigned to either a training (n = 10) or control (n = 10) group. The training group exercised for 1 hour, 3 days per week during the 12 week supervised training program. The training program included 3 sets of 10 repetition maximum (10RM) resistance exercise as well as aerobic exercise at an intensity of 60-70% of their heart rate reserve (HRR). The control group was asked to maintain their normal daily activities. Two-way (group X time) repeated measured analysis of variance revealed no significant main effects, but there was a significant group X time interaction for the following variables: body weight (p < 0.01), percent body fat (% fat) (p < 0.01), waist hip ratio (WHR) (p < 0.01), diastolic blood pressure (DBP) (p < 0.05), fasting glucose level (p < 0.01), triglyceride levels (TG) (p < 0.01), high density lipoprotein cholesterol levels (HDL-C) (p < 0.05), and visfatin (p < 0.01). In conclusion, the 12 week combined resistance and aerobic training program used in this study was very effective for producing significant benefits to body composition and metabolic syndrome factors, as well as lowering visfatin levels in these obese middle-aged women. Key pointsRecent studies have linked visfatin to obesity and increased health risks.The study was done to investigate the effects of 12 weeks of combined exercise training on visfatin and metabolic syndrome factors in obese middle-aged women.The exercise program used in this study was found to be very effective for lowering visfatin levels in obese middle-aged women.

Localized Corrosion Resistance on Additively Manufactured Ti Alloys by Means of Electrochemical Critical Localized Corrosion Potential in Biomedical Solution Environments.

This study proposes a new method, electrochemical critical localized corrosion potential (E-CLCP), in order to evaluate localized corrosion resistance of biomedical additive manufacturing (AM) titanium (Ti) alloys. The procedures for determining E-CLCP are completely different from that of the electrochemical critically localized corrosion temperature (E-CLCT) method (ISO 22910:2020). However, its application should be limited to pH and temperature of the human body because of the temperature scan. E-CLCP displays the localized corrosion resistance of AM Ti alloys based on the human body's repassivation kinetics, whereas E-CLCT displays the localized corrosion resistance of the alloys based on passive film breakdown in much harsher corrosive environments.

The Effects of Number of Fire Dispatches and Other Situational Factors on Voluntary Exercise Training Among Korean Firefighters: A Multilevel Logistic Regression Analysis.

According to previous research, participation in exercise training (ET) by South Korean firefighters varies with shift type, and the effect of shift type is greater in large cities than in small towns. However, shift types differ among regions, depending on the number of dispatches. Therefore, the present study examined the impact of the number of fire dispatches and other situational factors on ET. A series of multilevel logistic regression analysis was applied to analyze the data collected from South Korean firefighters (N = 5219) in 2017. According to the firefighters, participation in ET is higher among those who have someone to instruct their ET (Coefficient (Coef) = 0.057, SE = 0.017, p < 0.001) and who can do ET while on duty (Coef = 0.048, SE = 0.014, p < 0.001). The number of fire dispatches had a significant effect on participation in ET (Coef = -0.000, SE = 0.000, p < 0.01), meaning that the firefighters' participation in ET varies with the number of fire dispatches in each region. Our main findings indicate that the number of fire dispatches is a key factor affecting ET participation among firefighters, and the other situational factors also play a role. Therefore, ET programs that firefighters can participate in between calls should be established.

Predicting Voluntary Exercise Training among Korean Firefighters: Using Elicitation Study and the Theory of Planned Behavior.

Background: Firefighters are required to have high levels of aerobic and anaerobic power because they often perform physically demanding work in dangerous environments. Therefore, it is important to find out salient factors influencing voluntary exercise training among Korean firefighters based on well-validated theory. Methods: The present study conducted an elicitation study to elicit salient behavioral, normative, and control beliefs about exercise training among Korean firefighters and identified salient beliefs that have a significant indirect effect on behavior through intention using structural equation modeling. Results: Although ten modal salient beliefs obtained from our elicitation study are similar to those elicited from previous TPB belief-based research with a focus on exercise behavior, only three of these (i.e., "improves my physical ability" (coef. = 0.078, p = 0.006), "takes too much time" (coef. = 0.064, p = 0.023), and "colleagues" (coef. = 0.069, p = 0.016) indirectly influenced exercise training behavior through intention among Korean firefighters. Conclusions: Our results may contribute to the literature by providing important information suggesting that three modal salient beliefs are major cognitive determinants of exercise training behavior among Korean firefighters and they may play an essential role in developing effective programs or policies for promoting Korean firefighters' exercise training.

Relationship between Shift Type and Voluntary Exercise Training in South Korean Firefighters.

BACKGROUND: According to the National Fire Agency, 69% of South Korean firefighters prefer the three circuit system. Since the three circuit system involves working for 24 h consecutively, it could reduce work performance of firefighters and their participation in exercise training (ET) and fitness levels could be affected by shift type. The present study examined the impact of shift type on ET and identified the interaction effect between shift type and city size on ET among South Korean firefighters. METHODS: A series of logistic regression models were used to analyze the data collected from incumbent outside workers among Korean firefighters (N = 5196) in 2017. RESULTS: Firefighters under the 3 circuit system participated in ET less frequently than did those under the 21 circuit system, and the difference was greater in large cities than in small towns. This could be because of the greater opportunity to participate in leisure activities in large cities, or because participating in ET is easier for firefighters in small towns, who tend to be less busy than those in large cities. CONCLUSIONS: The three circuit system is not feasible in the present situation in South Korea. Therefore, an environment suitable for the three circuit system should be established.

Echocardiography Evaluation of Left Ventricular Diastolic Function in Elderly Women with Metabolic Syndrome.

To date, we found no published reports on the effects of metabolic syndrome and physical activity levels on left ventricular (LV) diastolic function in elderly women aged over 65 years. Our study involved patients with echocardiographically normal LV ejection fractions (≥50%) and normal LV dilatation diameters (≤55 mm). Elderly women with metabolic syndrome (n = 20) and healthy elderly women (n = 17) were selected and assessed with the National Cholesterol Education Program Adult Treatment Panel III, a metabolic syndrome diagnostic instrument. We compared the LV function indices and physical activity levels according to the presence (metabolic syndrome group) or absence (normal group) of metabolic syndrome. The LV end-systolic (LVES) diameter was significantly smaller (p = 0.037) and LV outflow tract (LVOT) diameter was significantly larger (p = 0.030) in the metabolic syndrome group. The left arterial dimension at end-systole (p = 0.024), left arterial volume (LAV) index (p = 0.015), early peak mitral inflow velocity (E, p = 0.031), early diastolic mitral annulus motion velocity (E'-septal, p = 0.044), (E'-lateral, p = 0.008), and E/late peak mitral inflow velocity ratio (E/A, p = 0.006) values were significantly lower and physical activity levels (p = 0.034) were significantly higher in the metabolic syndrome group. These results indicated that the metabolic syndrome group had relatively high physical activity levels compared to the normal group, which may have positively affected the LVES, LVOT, left atrial volume index, E, E', and E/A values.

Analysis of physical fitness and technical skills of youth soccer players according to playing position.

The purpose of this study was to compare performance factors of youth soccer players according to position. A total of 101 high school soccer players were selected and were classified into goalkeeper (n=7), defense (n=37), midfield (n=39), and forward (n=18) positions. All subjects were subjected to the Wingate test for anaerobic capacity, shuttle run test for aerobic capacity, and pass, kick, dribble, and shooting tests for soccer skills. There was no significant difference in aerobic capacity according to position. However, anaerobic capacity was significantly higher in defenders than midfielders (P<0.05), and soccer skills were significant lower in goalies than in other positions (P<0.01). The results show significant differences in anaerobic capacity and soccer skills according to position in youth soccer players. Therefore, we suggest that middle and high school soccer players should improve aerobic, an-aerobic capacity, and soccer skills irrespective position to achieve high-level soccer performance.