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Although the treadmill and cycle ergometer are commonly used for exercise stress electrocardiography (ECG) testing, they are often difficult to perform with children. We herein evaluated the utility and safety of the 2-minute jump test (2MJT) as a simple, alternative exercise test. One hundred patients, including 60 male patients, with an average age at study commencement of 10.7±3.5 years (mean±standard deviation) and with no exercise restriction who underwent a cardiac check-up between November 2020 and March 2022 at the study center were included. After recording their resting ECG, they jumped for 2 minutes during ECG recording, and the change in heart rate (HR), ECG findings, and occurrence of adverse events were investigated. As a result, patients jumped 185±60 times in two minutes, and their HR increased from 76±13 beats/min at rest to 172±18 beats/min at peak during the test. Ninety (90%) patients attained the ideal target HR of > 150 beats/minute. During the recovery period after loading, five patients had abnormal ECG findings (ventricular extrasystoles, second-degree atrioventricular block, and atrial extrasystoles in two, two, and one patient, respectively) but completely resolved spontaneously within three minutes. Our findings suggested that the 2MJT is a useful and safe exercise test capable of inducing sufficient increase in HR in a short time in children. [ABSTRACT FROM AUTHOR]

Background: Rating of perceived exertion (RPE) is considered a valid method for prescribing prolonged aerobic steady-state exercise (SSE) intensity due to its association with physiological indicators of exercise intensity, such as oxygen uptake (V̇O2) or heart rate (HR). However, these associations between psychological and physiological indicators of exercise intensity were found during graded exercise tests (GXT) but are currently used to prescribe SSE intensity even though the transferability and validity of the relationships found during GXT to SSE were not investigated. The present study aims to verify whether (a) RPE-HR or RPE-V̇O2 relations found during GXTs are valid during SSEs, and (b) the duration and intensity of SSE affect these relations. Methods: Eight healthy and physically active males (age 22.6 ± 1.2 years) were enrolled. On the first visit, pre-exercise (during 20 min standing) and maximal (during a GXT) HR and V̇O2 values were measured. Then, on separate days, participants performed 4 SSEs on the treadmill by running at 60% and 80% of the HR reserve (HRR) for 15 and 45 min (random order). Individual linear regressions between GXTs' RPE (dependent variable) and HRR and V̇O2 reserve (V̇O2R) values (computed as the difference between maximal and pre-exercise values) were used to predict the RPE associated with %HRR (RPEHRR) and %V̇O2R (RPEV̇O2R) during the SSEs. For each relation (RPE-%HRR and RPE-%V̇O2R), a three-way factorial repeated measures ANOVA (α = 0.05) was used to assess if RPE (dependent variable) was affected by exercise modality (i.e., RPE recorded during SSE [RPESSE] or GXT-predicted), duration (i.e., 15 or 45 min), and intensity (i.e., 60% or 80% of HRR). Results: The differences between RPESSE and GXT-predicted RPE, which were assessed by evaluating the effect of modality and its interactions with SSE intensity and duration, showed no significant differences between RPESSE and RPEHRR. However, when RPESSE was compared with RPEV̇O2R, although modality or its interactions with intensity were not significant, there was a significant (p = 0.020) interaction effect of modality and duration yielding a dissociation between changes of RPESSE and RPEV̇O2R over time. Indeed, RPESSE did not change significantly (p = 0.054) from SSE of 15 min (12.1 ± 2.0) to SSE of 45 min (13.5 ± 2.1), with a mean change of 1.4 ± 1.8, whereas RPEV̇O2R decreased significantly (p = 0.022) from SSE of 15 min (13.7 ± 3.2) to SSE of 45 min (12.4 ± 2.8), with a mean change of −1.3 ± 1.5. Conclusion: The transferability of the individual relationships between RPE and physiological parameters found during GXT to SSE should not be assumed as shown by the results of this study. Therefore, future studies modelling how the exercise prescription method used (e.g., RPE, HR, or V̇O2) and SSE characteristics (e.g., exercise intensity, duration, or modality) affect the relationships between RPE and physiological parameters are warranted. [ABSTRACT FROM AUTHOR]

Background Rating of perceived exertion (RPE) is considered a valid method for prescribing prolonged aerobic steady-state exercise (SSE) intensity due to its association with physiological indicators of exercise intensity, such as oxygen uptake (V̇O2) or heart rate (HR). However, these associations between psychological and physiological indicators of exercise intensity were found during graded exercise tests (GXT) but are currently used to prescribe SSE intensity even though the transferability and validity of the relationships found during GXT to SSE were not investigated. The present study aims to verify whether (a) RPE-HR or RPE-V̇O2 relations found during GXTs are valid during SSEs, and (b) the duration and intensity of SSE affect these relations. Methods Eight healthy and physically active males (age 22.6 ± 1.2 years) were enrolled. On the first visit, pre-exercise (during 20 min standing) and maximal (during a GXT) HR and V̇O2 values were measured. Then, on separate days, participants performed 4 SSEs on the treadmill by running at 60% and 80% of the HR reserve (HRR) for 15 and 45 min (random order). Individual linear regressions between GXTs’ RPE (dependent variable) and HRR and V̇O2 reserve (V̇O2R) values (computed as the difference between maximal and pre-exercise values) were used to predict the RPE associated with %HRR (RPEHRR) and %V̇O2R (RPEV̇O2R) during the SSEs. For each relation (RPE-%HRR and RPE-%V̇O2R), a three-way factorial repeated measures ANOVA (α = 0.05) was used to assess if RPE (dependent variable) was affected by exercise modality (i.e., RPE recorded during SSE [RPESSE] or GXT-predicted), duration (i.e., 15 or 45 min), and intensity (i.e., 60% or 80% of HRR). Results The differences between RPESSE and GXT-predicted RPE, which were assessed by evaluating the effect of modality and its interactions with SSE intensity and duration, showed no significant differences between RPESSE and RPEHRR. However, when RPESSE was compared with RPEV̇O2R, although modality or its interactions with intensity were not significant, there was a significant (p = 0.020) interaction effect of modality and duration yielding a dissociation between changes of RPESSE and RPEV̇O2R over time. Indeed, RPESSE did not change significantly (p = 0.054) from SSE of 15 min (12.1 ± 2.0) to SSE of 45 min (13.5 ± 2.1), with a mean change of 1.4 ± 1.8, whereas RPEV̇O2R decreased significantly (p = 0.022) from SSE of 15 min (13.7 ± 3.2) to SSE of 45 min (12.4 ± 2.8), with a mean change of −1.3 ± 1.5. Conclusion The transferability of the individual relationships between RPE and physiological parameters found during GXT to SSE should not be assumed as shown by the results of this study. Therefore, future studies modelling how the exercise prescription method used (e.g., RPE, HR, or V̇O2) and SSE characteristics (e.g., exercise intensity, duration, or modality) affect the relationships between RPE and physiological parameters are warranted.

Abstract Purpose Waste collection is considered particularly heavy work, although no previous study has yet investigated the strain of bulk waste collection. The aim of this study is to determine the workload of bulk waste workers in practice. Method We conducted a cross-sectional field-study. Fourteen male volunteers from the bulk waste collection of the municipal sanitation department in Hamburg, Germany, were included. Performance was determined by cardiopulmonary exercise testing under laboratory conditions. During the shift, each worker was accompanied by a researcher, and heart rate (HR) was recorded under field conditions using an HR watch with a belt system. We examined mean HR, relative heart rate (RHR), relative aerobic strain (RAS), calculated oxygen uptake ( $$\mathrm{\overset{.}{V}O}_2$$ V . O 2 ) and individual ventilatory threshold 1 (VT1) as parameters of workload during their daily work. Results During the shift, HR was scaled: 102 bpm (SD 10.2), RHR: 36.9%, $$\mathrm{\overset{.}{V}O}_2$$ V . O 2 : 1267 ml/min (SD 161), RAS: 49.4% (SD 9.3), and $$\mathrm{\overset{.}{V}O}_2$$ V . O 2 in relation to VT1: 75% (SD 18.5). There was no significant difference between oxygen consumption during the main task of lifting and carrying bulky waste and the individual $$\mathrm{\overset{.}{V}O}_2$$ V . O 2 at VT1. Conclusion Although the burden of the main task of lifting and carrying bulky waste is very high (at VT1 for more than 3 h), interruptions from other tasks or formal breaks spread the burden over the entire shift. The total workload exceeded most recommendations in the literature across the different work periods. However, the total burden remains below VT1, the only parameter that takes individual endurance performance into account. We recommend again VT1 as an individual upper limit for prolonged occupational work.

Purpose: Waste collection is considered particularly heavy work, although no previous study has yet investigated the strain of bulk waste collection. The aim of this study is to determine the workload of bulk waste workers in practice. Method: We conducted a cross-sectional field-study. Fourteen male volunteers from the bulk waste collection of the municipal sanitation department in Hamburg, Germany, were included. Performance was determined by cardiopulmonary exercise testing under laboratory conditions. During the shift, each worker was accompanied by a researcher, and heart rate (HR) was recorded under field conditions using an HR watch with a belt system. We examined mean HR, relative heart rate (RHR), relative aerobic strain (RAS), calculated oxygen uptake ( V. O 2 ) and individual ventilatory threshold 1 (VT1) as parameters of workload during their daily work. Results: During the shift, HR was scaled: 102 bpm (SD 10.2), RHR: 36.9%, V. O 2 : 1267 ml/min (SD 161), RAS: 49.4% (SD 9.3), and V. O 2 in relation to VT1: 75% (SD 18.5). There was no significant difference between oxygen consumption during the main task of lifting and carrying bulky waste and the individual V. O 2 at VT1. Conclusion: Although the burden of the main task of lifting and carrying bulky waste is very high (at VT1 for more than 3 h), interruptions from other tasks or formal breaks spread the burden over the entire shift. The total workload exceeded most recommendations in the literature across the different work periods. However, the total burden remains below VT1, the only parameter that takes individual endurance performance into account. We recommend again VT1 as an individual upper limit for prolonged occupational work. [ABSTRACT FROM AUTHOR]

The present study aimed at designing a simple, affordable, yet safe transfer assistive device (TAD) for lower limb impaired individuals in the context of a developing country. The preliminary study carried out, comprising a pilot survey with the involvement of stakeholder's views to design and develop the proposed device that had a unique feature. To evaluate the present TAD in terms of user's comfort of use and level of physical strain, subjects including 19 healthy students serving as "patients" have participated in a laboratory-simulated setting. Data was collected based on user's physiologic effort and rate of perceived exertion using Heart rate monitoring device (Polar RS 400 heart taster) and Borg's scale, respectively. The data were analysed statistically and revealed that the regression equation for predicting the RPE from HR showed 31.3 % of the variance in RPE was predictable from the level of HR. The ANOVA significance also indicates the model is statistically significant with (p < 0.013). Similarly, the estimated strain level has computed in terms of %HRR, and the physical strain averaged over the subjects who performed the task (n = 19) was expressed in terms of (mean ± SD) %HRR were ( 16.21 ± 7.64 %) which was a relatively smaller strain level as compared to the previous research report. The present device found a potentially affordable solution for reducing fatigue and strain level that might develop during unassisted transfer. Similarly, the unique feature of the armpit support has contributed to dynamic contact force reduction and as double safety support. The use of transfer assistive device is associated with increased patient satisfaction and privacy of users Improved patient adherence and cooperation with caregivers in rehabilitation center. Encourages the rehabilitation settings to use transfer assistive devices instead of manual handling there by increase the recovery period. [ABSTRACT FROM AUTHOR]

OBJECTIVES: Contrary to leisure-time physical activity, occupational physical activity (OPA) may have harmful health effects, called the physical activity paradox. A proposed mechanism is that OPA can elevate the heart rate (HR) for several hours per day. We aimed to investigate the association between the mean intensity of OPA and HR variability (HRV) indices the following night. METHODS: Three cohorts (NOMAD, DPhacto, and Physical Workload and Fitness) involving blue-collar workers from different sectors were merged in this study. HR monitors (Actiheart) recorded 24-hour inter-beat intervals (IBI) for up to four consecutive days. The relative intensity of the mean HR during work was estimated by HR reserve (%HRR), and time-domain indices of HRV were analyzed during the following night. Data were analyzed using a multilevel growth model to test the association between mean %HRR during work and HRV indices at night in a day-by-day analysis adjusted for age, BMI, alcohol consumption, smoking, and occupation. RESULTS: The dataset included a sample of 959 Danish blue-collar workers, with a mean %HRR during work of 31%, and 42% worked at an intensity ≥30%HRR. The multilevel model showed negative within- and between-subject associations between %HRR during work and HRV indices at night. CONCLUSIONS: Our results indicate a higher %HRR during work to associate with lower HRV indices the following night and a higher HR, reflecting an imbalanced autonomic cardiac modulation. This finding supports a high mean HR during work to be a potential underlying mechanism for the harmful health effect of OPA.

Package deliverers are facing increasing workloads due to a rapid increase in online shopping caused by the recent outbreak of COVID-19 in the Republic of Korea. The purpose of this study was to evaluate the physical workload of package deliverers during pickup and delivery tasks. Heart rate reserve (HRR), metabolic equivalent of task (MET), standardized Nordic questionnaire (SNQ), and visual analogue scale (VAS), measured on site using a wristband, were used as indicators of their workload. Twenty deliverers participated in this study. Work analysis was performed to categorize their tasks into sorting inside a truck, delivering, picking up, driving, and resting. Statistical analysis showed that participants spend 4.3 h per day picking up and delivering 331.9 packages per day. Their work requires about 29.7% of HRR and 4.7 of MET, which are thus considered as of "moderate level" difficulty. SNQ and VAS revealed that their lower back and wrist/hand were the most painful body parts due to repetitive trunk bending and small package handling. The use of a cart would be recommended as it has the advantage of handling many packages at once with less physical effort in deliverers. [ABSTRACT FROM AUTHOR]

This study was to explore the correlation between heart rate reserve (HRR) to coronary flow velocity reserve (CFVR), using adenosine stress echocardiography (SE), in patients with angina and no obstructive coronary artery disease (ANOCA). 111 ANOCA patients underwent adenosine SE were enrolled, which were divided into two groups, impaired CFVR group (CFVR < 2) and control groups (CFVR ≥ 2). The relationships between HRR and impaired CFVR were explored in total and subgroup to sex. A reduced HRR during adenosine infusion was seen in ANOCA patients with impaired CFVR (25.73 ± 8.39 vs. 34.30 ± 19.93, P < 0.001). Compared to respective controls, the blunted HRR to adenosine was more pronounced in female patients (women: 27.21 ± 8.01 vs. 39.48 ± 10.57, P < 0.001; men: 24.05 ± 8.70 vs. 29.12 ± 8.69, P = 0.041). A strong association between CFVR and a blunted HRR was observed in women (r = 0.46, P < 0.001), while no association in men (r = 0.18, P = 0.199). In female, a multivariate logistic regression identified HRR as the strongest negative predictor of impaired CFVR [HR (95% CI) = 0.854 (0.764–0.956), P = 0.006]. Based on the ROC curve, HRR < 35% was a strong indicator of impaired CFVR, with AUC of 0.838, sensitivity of 70%, and specificity of 87% in females. A blunted HRR was seen in patients with impaired CFVR, with a most pronounced effect being seen in female patients. The blunted HRR < 35% is intricately linked to impaired CFVR in women with ANOCA beyond the value of traditional risk factors, which could ultimately contribute to risk stratification of impaired CFVR in such patients. [ABSTRACT FROM AUTHOR]

Background. The percentages of heart rate (%HRR) or oxygen uptake (%V̇O2R) reserve are used interchangeably for prescribing aerobic exercise intensity due to their assumed 1:1 relationship, although its validity is debated. This study aimed to assess if %HRR and %V̇O2R show a 1:1 relationship during steady-state exercise (SSE) and if exercise intensity and duration affect their relationship. Methods. Eight physically active males (age 22.6 ± 1.2 years) were enrolled. Pre-exercise and maximal HR and V̇O2 were assessed on the first day. In the following 4 days, different SSEs were performed (running) combining the following randomly assigned durations and intensities: 15 min, 45 min, 60% HRR, 80% HRR. Post-exercise maximal HR and V̇O2 were assessed after each SSE. Using pre-exercise and post-exercise maximal values, the average HR and V̇O2 of the last 5 min of each SSE were converted into percentages of the reserves (%RES), which were computed in a 3-way RM-ANOVA (α = 0.05) to assess if they were affected by the prescription parameter (HRR or V̇O2R), exercise intensity (60% or 80% HRR), and duration (15 or 45 min). Results. The %RES values were not affected by the prescription parameter (p = 0.056) or its interactions with intensity (p = 0.319) or duration and intensity (p = 0.117), while parameter and duration interaction was significant (p = 0.009). %HRRs and %V̇O2Rs did not differ in the 15-min SSEs (mean difference [MD] = 0.7 percentage points, p = 0.717), whereas %HRR was higher than %V̇O2R in the 45-min SSEs (MD = 6.7 percentage points, p = 0.009). Conclusion. SSE duration affects the %HRR-%V̇O2R relationship, with %HRRs higher than %V̇O2Rs in SSEs of longer duration. [ABSTRACT FROM AUTHOR]

Background The percentages of heart rate (%HRR) or oxygen uptake (%V̇O2R) reserve are used interchangeably for prescribing aerobic exercise intensity due to their assumed 1:1 relationship, although its validity is debated. This study aimed to assess if %HRR and %V̇O2R show a 1:1 relationship during steady-state exercise (SSE) and if exercise intensity and duration affect their relationship. Methods Eight physically active males (age 22.6 ± 1.2 years) were enrolled. Pre-exercise and maximal HR and V̇O2 were assessed on the first day. In the following 4 days, different SSEs were performed (running) combining the following randomly assigned durations and intensities: 15 min, 45 min, 60% HRR, 80% HRR. Post-exercise maximal HR and V̇O2 were assessed after each SSE. Using pre-exercise and post-exercise maximal values, the average HR and V̇O2 of the last 5 min of each SSE were converted into percentages of the reserves (%RES), which were computed in a 3-way RM-ANOVA (α = 0.05) to assess if they were affected by the prescription parameter (HRR or V̇O2R), exercise intensity (60% or 80% HRR), and duration (15 or 45 min). Results The %RES values were not affected by the prescription parameter (p = 0.056) or its interactions with intensity (p = 0.319) or duration and intensity (p = 0.117), while parameter and duration interaction was significant (p = 0.009). %HRRs and %V̇O2Rs did not differ in the 15-min SSEs (mean difference [MD] = 0.7 percentage points, p = 0.717), whereas %HRR was higher than %V̇O2R in the 45-min SSEs (MD = 6.7 percentage points, p = 0.009). Conclusion SSE duration affects the %HRR-%V̇O2R relationship, with %HRRs higher than %V̇O2Rs in SSEs of longer duration.

Objectives Contrary to leisure-time physical activity, occupational physical activity (OPA) may have harmful health effects, called the physical activity paradox. A proposed mechanism is that OPA can elevate the heart rate (HR) for several hours per day. We aimed to investigate the association between the mean intensity of OPA and HR variability (HRV) indices the following night. Methods Three cohorts (NOMAD, DPhacto, and Physical Workload and Fitness) involving blue-collar workers from different sectors were merged in this study. HR monitors (Actiheart) recorded 24-hour inter-beat intervals (IBI) for up to four consecutive days. The relative intensity of the mean HR during work was estimated by HR reserve (%HRR), and time-domain indices of HRV were analyzed during the following night. Data were analyzed using a multilevel growth model to test the association between mean %HRR during work and HRV indices at night in a day-by-day analysis adjusted for age, BMI, alcohol consumption, smoking, and occupation. Results The dataset included a sample of 878 Danish blue-collar workers, with a mean %HRR during work of 31%, and 42% worked at an intensity ≥30%HRR. The multilevel model showed negative within- and between-subject associations between %HRR during work and HRV indices at night. Conclusions Our results indicate a higher %HRR during work to associate with lower HRV indices the following night and a higher HR, reflecting an imbalanced autonomic cardiac modulation. This finding supports a high mean HR during work to be a potential underlying mechanism for the harmful health effect of OPA. [ABSTRACT FROM AUTHOR]

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Objective: To noninvasively explore the heat intolerance condition during exercise-heat stress by assessing cardiovascular (CV) performance. Design: Prospective study of participants undergoing a standard heat-tolerance test (HTT). Setting: Institutional study. Participants: Ninety-five young males: 16 heat-intolerant (HI) and 79 heat-tolerant (HT). Interventions: Cardiovascular performance during an HTT was estimated by heart rate (HR) and blood pressure measurements. Main outcome measures: The sensitivity of the cardiovascular reserve index (CVRI) and the dynamic heart rate reserve (dHRR) index to predict heat intolerance was compared. Results: A significant difference in the CV reserve during exercise-heat stress was exhibited between the HI and the HT groups. Starting at a similar level, the reduction in the CV reserve at HTT endpoint was much greater in the HI than the HT individuals (P < 0.0001), as depicted by both the CVRI and the dHRR. This result indicates a greater utilization of the CV reserve by HI individuals. The CVRI is likely to be better predictor of heat intolerance than the dHRR because the partial area under the curve in the high sensitivity (>90%) region of its receiver operating characteristic curve is higher (93.2 vs 76.8). Conclusions: More than being a predictor, the CVRI may provide a new clinical insight into heat intolerance because it noninvasively characterizes the efficiency of an individual's thermoregulatory mechanism and hints that an impaired CV reserve might underlie heat intolerance. The CVRI provides a noninvasive measurement of thermoregulation, which has been long awaited to enable on-field studies and dynamic monitoring of heat-exposed task forces. [ABSTRACT FROM AUTHOR]

Background: The knowledge, from laboratory studies dating back to the 1950s on the importance of the association between cardiorespiratory fitness and aerobic workload for workers health, is fundamental for promoting sustainable healthy employability among ageing blue-collar workers today. However, the association between cardiorespiratory fitness and aerobic workload has not yet been documented during daily work, and we do not know if it applies to the normal work of blue-collar workers in different age groups. We aim to investigate the association between cardiorespiratory fitness and aerobic workload among blue-collar workers using measurements of 24-h heart rate collected over consecutive working days. Methods: We analyzed baseline cardiorespiratory fitness, assessed using a sub-maximal cycle ergometer test, and 1–4 days of 24-h heart rate measurement from 497 blue-collar workers participating in the DPHACTO study. We investigated the association between cardiorespiratory fitness and aerobic workload defined as the average percentage of heart rate reserve (%HRR), maximum %HRR and the duration time spent at a high HRR (> 30%) during working hours. The association was assessed using multivariate linear regression models adjusted for age, sex, self-rated health, shift-work, prescription medication and occupation, as well as for different age strata. Results: Higher cardiorespiratory fitness was significantly associated with decreased mean %HRR −0.32 [95% CI −0.39 to −0.25], maximum %HRR −0.35 [95% CI −0.45 to −0.25] and time spent at ≥ 30% HRR; −1.8% [95% CI −2.2 to −1.5%]. These associations were evident across age groups, with slightly stronger associations for workers aged 46–51 (total range 18–68). Conclusions: Higher cardiorespiratory fitness was associated with the decreased aerobic workload during normal work across all age groups and levels of work intensity. Our findings highlight the importance of cardiorespiratory fitness when considering the workload and its relevance in the promotion of healthy sustainable employment. [ABSTRACT FROM AUTHOR]

Background: Peak oxygen uptake (peak VO2) and heart rate reserve (HRR) are independent prognostic markers of cardiovascular disease. However, the impact of peak VO2 and HRR on long‐term prognosis after off‐pump coronary artery bypass grafting (OP‐CABG) remains unclear. Hypothesis: To determine the prognostic impact of peak VO2 and HRR in patients after OP‐CABG. Results: We enrolled 327 patients (mean age, 65.1 ± 9.3 years; male, 80%) who underwent OP‐CABG and participated in early phase II cardiac rehabilitation. All participants underwent cardiopulmonary exercise testing (CPET) at the beginning of such rehabilitation. Overall, 48 (14.6%) patients died during the median follow‐up period of 103 months. The non‐survivor had significantly lower levels of peak VO2 (10.6 ± 0.5 vs. 13.7 ± 0.2 ml/kg/min, p <.01) and HRR (24.2 ± 1.8 vs. 32.7 ± 0.8 beats/min, p <.01) than the survivor. In both groups, peak VO2 significantly correlated with HRR (p <.01). Moreover, patients were divided into four groups according to the peak VO2 and HRR levels for predicting total mortality. The low‐peak VO2/low‐HRR group had a significantly higher mortality risk than the other groups (hazards ratio, 5.61; 95% confidence interval, 2.59–12.16; p <.01). After adjusted the confounding factors, peak VO2 and HRR were independently associated with total mortality (both p <.05). Conclusions: HRR is a simple parameter of CPET and an important prognostic marker for the risk stratification of total mortality even in patients with low‐peak VO2 after OP‐CABG. [ABSTRACT FROM AUTHOR]

Objectives The aim of the study is to evaluate the intensity of the effort and energy expenditure in the course of performing selected classical massage techniques and to assess the workload of a massage therapist during a work shift. Material and Methods Thirteen massage therapists (age: 21.9±1.9 years old, body mass index: 24.5±2.8 kg×m –2 , maximal oxygen consumption × body mass –1 (VO 2max ×BM –1 ): 42.3±7 ml×kg –1 ×min –1 ) were involved in the study. The stress test consisted in performing selected classical massage techniques in the following order: stroking, kneading, shaking, beating, rubbing and direct vibration, during which the cardio-respiratory responses and the subjective rating of perceived exertion (RPE) were assessed. Intensity of exercise during each massage technique was expressed as % VO 2max , % maximal heart rate (HR max ) and % heart rate reserve (HRR). During each massage technique, net energy expenditure (EE) and energy cost of work using metabolic equivalent of task (MET) were determined. Results The intensity of exercise was 47.2±6.2% as expressed in terms of % VO 2max , and 74.7±3.2% as expressed in terms of % HR max , while it was 47.8±1.7% on average when expressed in terms of % HRR during the whole procedure. While performing the classical massage, the average EE and MET were 5.6±0.9 kcal×min –1 and 5.6±0.2, respectively. The average RPE calculated for the entire procedure was 12.1±1.4. During the performance of a classical massage technique for a single treatment during the study, the average total EE was 176.5±29.6 kcal, resulting in an energy expenditure of 336.2±56.4 kcal×h –1 . In the case of the classical massage technique, rubbing was the highest intensity exercise for the masseur who performed the massage (%VO 2max = 57.4±13.1%, HR max = 79.6±7.7%, HRR = 58.5±13.1%, MET = 6.7±1.1, EE = 7.1±1.4 kcal×min –1 , RPE = 13.4±1.3). Conclusions In the objective assessment, physical exercise while performing a single classical massage is characterized by hard work. The technique of classical massage during which the masseur performs the highest exercise intensity is rubbing. According to the classification of work intensity based on energy expenditure, the masseur’s work is considered heavy during the whole work shift. Int J Occup Med Environ Health 2018;31(5):677–684

Background: Dobutamine stress echocardiography (DSE) is a commonly used diagnostic stress test for the assessment of various cardiac pathologies on patients unable to perform exercise. Unlike exercise, there is no reliable subjective termination end-point such as fatigue to rely on. Consequently, DSE's are often concluded at a predetermined age predicted maximal heart rate (APMHR) such as 85%. The aim of this study was to assess if APMHR, heart rate reserve (HRR) and the maximum rate pressure product (MRPP) are valid measures of future cardiovascular (CV) events in otherwise negative DSEs. Methods: Following exclusions, receiver operating curve (ROC) analyses were performed on 652 patients using CV events during the follow-up period (4.2 ± 1.8 years) as the outcome variable. Results: ROC analyses failed to produce a statistically valid model for MRPP (p =.227, area under curve (AUC)=0.55) with a sensitivity and specificity of 21.1% and 91.9%, respectively at the optimal cut point (14948 MRPP). To the contrary, APMHR produced a sensitivity and specificity of 74.7% and 60.9%, respectively (p <.0001, AUC = 0.715). HRR however, with a sensitivity and specificity of 67.4% and 68.2% (p <.0001, AUC = 0.718) was the only predictor of CV events following Cox analysis (p <.0001). Conclusions: This study demonstrates MRPP as a poor measure of CV event prediction during DSE. While an APMHR of 89.3% demonstrated a statistically valid model, HRR was the only predictor of CV events in otherwise negative DSEs. [ABSTRACT FROM AUTHOR]

Background Inertial sensors, such as accelerometers, serve as convenient devices to predict the energy expenditures (EEs) during physical activities by a predictive equation. Although the accuracy of estimate EEs especially matter to athletes receive physical training, most EE predictive equations adopted in accelerometers are based on the general population, not athletes. This study included the heart rate reserve (HRR) as a compensatory parameter for physical intensity and derived new equations customized for sedentary, regularly exercising, non-endurance athlete, and endurance athlete adults. Methods With indirect calorimetry as the criterion measure (CM), the EEs of participants on a treadmill were measured, and vector magnitudes (VM), as well as HRR, were simultaneously recorded by a waist-worn accelerometer with a heart rate monitor. Participants comprised a sedentary group (SG), an exercise-habit group (EHG), a non-endurance group (NEG), and an endurance group (EG), with 30 adults in each group. Results EE predictive equations were revised using linear regression with cross-validation on VM, HRR, and body mass (BM). The modified model demonstrates valid and reliable predictions across four populations (Pearson correlation coefficient, r: 0.922 to 0.932; intraclass correlation coefficient, ICC: 0.919 to 0.930). Conclusion Using accelerometers with a heart rate monitorcan accurately predict EEs of athletes and non-athletes with an optimized predictive equation integrating the VM, HRR, and BM parameters.

Background Using wearable inertial sensors to accurately estimate energy expenditure (EE) during an athletic training process is important. Due to the characteristics of inertial sensors, however, the positions in which they are worn can produce signals of different natures. To understand and solve this issue, this study used the heart rate reserve (HRR) as a compensation factor to modify the traditional empirical equation of the accelerometer EE sensor and examine the possibility of improving the estimation of energy expenditure for sensors worn in different positions. Methods Indirect calorimetry was used as the criterion measure (CM) to measure the EE of 90 healthy adults on a treadmill (five speeds: 4.8, 6.4, 8.0, 9.7, and 11.3 km/h). The measurement was simultaneously performed with the ActiGraph GT9X-Link (placed on the wrist and waist) with the Polar H10 Heart Rate Monitor. Results At the same exercise intensity, the EE measurements of the GT9X on the wrist and waist had significant differences from those of the CM (p < 0.05). By using multiple regression analysis—utilizing values from vector magnitudes (VM), body weight (BW) and HRR parameters—accuracy of EE estimation was greatly improved compared to traditional equation. Modified models explained a greater proportion of variance (R2) (wrist: 0.802; waist: 0.805) and demonstrated a good ICC (wrist: 0.863, waist: 0.889) compared to Freedson’s VM3 Combination equation (R2: wrist: 0.384, waist: 0.783; ICC: wrist: 0.073, waist: 0.868). Conclusions The EE estimation equation combining the VM of accelerometer measurements, BW and HRR greatly enhanced the accuracy of EE estimation based on data from accelerometers worn in different positions, particularly from those on the wrist.

OBJECTIVES: To examine the relationship of clinical, biochemical and imaging parameters to maximum oxygen uptake in patients after atrial correction of transposition of great arteries. BACKGROUND: Exercise tolerance is a key determinant of quality of life in patients with adult congenital heart disease. It is determined by a large scale of factors often different from general cardiology. METHODS: 86 consecutive patients after Senning correction of TGA were subjected to clinical and echocardiographic examination, Holter monitoring, blood tests of NT-proBNP, MRI of the heart and exercise test. Parameters of these examinations were correlated to VO2 max. RESULTS: The average age of patients was 28±3.5 years. The average systemic right ventricular function determined by MRI was 51.9±7.9 %. The average NT-proBPN was 124.3±23.6 ng/l, VO2 max. 31.7±6.5 ml/kg/min and the heart rate reserve 106±24 /min. Neither systemic right ventricular systolic function nor NT-proBPN predicted VO2 max., whereas the heart rate reserve did (p=0.003). CONCLUSION: An inability to increase heart rate during exercise noted in a considerable number of patients after atrial switch of TGA caused a decreased exercise tolerance. It is not solely the global systolic function of either ventricle that influences the exercise performance, rather it is the ability to increase heart rate and overall cardiac output appropriately (Tab. 3, Fig. 6, Ref. 28). [ABSTRACT FROM AUTHOR]

Introduction: Heart rate (HR) monitors are rarely used by people living with disabilities (PLWD), and their accuracy is undocumented. Thus, this study aims to describe the HR response during the Team Twin co-running program and, secondly, to assess the agreement and accuracy of using HR monitors among PLWD., Methods: This 16-week single-arm observational study included 18 people with various disabilities. During the study, the subjects wore a Garmin Vivosmart 4 watch (wrist). To evaluate the agreement and accuracy we applied Garmin's HRM-DUAL™ chest-worn HR monitors for comparison with the Vivosmart 4. The HR response analysis was performed descriptively and with a mixed regression model. The HR agreement and accuracy procedure was conducted on a subsample of five subjects and analyzed using Lin's concordance analysis, Bland and Altman's limits of agreement, and Cohen's kappa analysis of intensity zone agreement. This study was prospectively registered at Clinical Trials.gov (NCT04536779)., Results: The subjects had a mean age of 35 (±12.6), 61% were male, 72% had cerebral palsy were 85% had GMFCS V-IV. HR was monitored for 202:10:33 (HH:MM:SS), with a mean HR of 90 ± 17 bpm during training and race. A total of 19% of the time was spent in intensity zones between light and moderate (30%-59% HR reserve) and 1% in vigorous (60%-84% HR reserve). The remaining 80% were in the very light intensity zone (<29% HR reserve). HR was highest at the start of race and training and steadily decreased. Inter-rater agreement was high (k = 0.75), limits of agreement were between -16 and 13 bpm, and accuracy was acceptable (Rc = 0.86)., Conclusion: Disability type, individual, and contextual factors will likely affect HR responses and the agreement and accuracy for PLWD. The Vivosmart 4, while overall accurate, had low precision due to high variability in the estimation. These findings implicate the methodical and practical difficulties of utilizing HR monitors to measure HR and thus physical activity in adapted sports activities for severely disabled individuals., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Jørgensen, Toftager, Eghøj, Ried-Larsen and Bjørk Petersen.)

To investigate the heart rate during cardio-pulmonary exercise (CPX) testing in individuals with type 1 diabetes (T1D) compared to healthy (CON) individuals. Fourteen people (seven individuals with T1D and seven CON individuals) performed a CPX test until volitional exhaustion to determine the first and second lactate turn points (LTP1 and LTP2), ventilatory thresholds (VT1 and VT2), and the heart rate turn point. For these thresholds cardio-respiratory variables and percentages of maximum heart rate, heart rate reserve, maximum oxygen uptake and oxygen uptake reserve, and maximum power output were compared between groups. Additionally, the degree and direction of the deflection of the heart rate to performance curve (kHR) were compared between groups. Individuals with T1D had similar heart rate at LTP1 (mean difference) −11, [(95% confidence interval) −27 to 4 b.min−1], at VT1 (−12, −8 to 33 b.min−1) and at LTP2 (−7, −13 to 26 b.min−1), at VT2 (−7, −13 to 28 b.min−1), and at the heart rate turn point (−5, −14 to 24 b.min−1) (p = 0.22). Heart rate expressed as percentage of maximum heart rate at LTP1, VT1, LTP2, VT2 and the heart rate turn point as well as expressed as percentages of heart rate reserve at LTP2, VT2 and the heart rate turn point was lower in individuals with T1D (p < 0.05). kHR was lower in T1D compared to CON individuals (0.11 ± 0.25 vs. 0.51 ± 0.32, p = 0.02). Our findings demonstrate that there are clear differences in the heart rate response during CPX testing in individuals with T1D compared to CON individuals. We suggest using submaximal markers to prescribe exercise intensity in people with T1D, as the heart rate at thresholds is influenced by kHR.Clinical Trial Identifier: NCT02075567 (https://clinicaltrials.gov/ct2/show/NCT02075567).

This study investigated whether ratings of perceived exertion (RPE) determined during maximal exercise testing would be reproduced during prolonged aerobic submaximal exercise performed with different relative intensities. Twenty-eight healthy men (18 to 34 yrs) performed ramp-incremental cardiopulmonary maximal exercise testing (CPET) to determine VO2R, followed by 40-min exercise bouts performed at intensities corresponding to 60%, 70%, and 80% VO2R. Strong correlations were observed between RPE versus %VO2R during CPET and all exercise bouts (r = 0.86 to 0.96; P<0.001). However, the RPE obtained for different %VO2R in CPET did not correspond to scores assessed each 10 min during the submaximal exercise. In all conditions, the RPE increased over time (P<0.001) so that scores obtained in CPET were not reproducible during the three submaximal bouts. Acceptable agreements reflected by lack of statistical difference between expected and actual RPE were observed in only the 10-min part of the 40-min bouts. The RPE obtained during CPET typically overestimated scores assessed at the beginning of submaximal exercise (1 to 5 points, P<0.001); whereas, an underestimation occurred after 20 min (1 to 3 points, P<0.001). In conclusion, although associated with the exercise intensity, the RPE corresponding to different %VO2R as determined in CPET did not correspond to the actual RPE during the 40-min submaximal exercise. This discrepancy might lead to errors when the exercise intensity is controlled by perceived exertion. [ABSTRACT FROM AUTHOR]

Purpose: Evidence to date has failed to adequately explore determinants of cardiovascular risk in women with coronary microvascular dysfunction (CMVD). Heart rate responses to adenosine mirror autonomic activity and may carry important prognostic information for the diagnosis of CMVD. Methods: Hemodynamic changes during adenosine stress were analyzed in a propensity-matched cohort of 404 patients (202 women, mean age 65.9 ± 11.0) who underwent clinically indicated myocardial perfusion 13N-ammonia Positron-Emission-Tomography (PET) at our institution between September 2013 and May 2017. Results: Baseline heart rate (HR) was significantly higher in patients with abnormal coronary flow reserve (CFR, p < 0.001 vs normal CFR). Accordingly, a blunted HR response to adenosine (=reduced heart rate reserve, %HRR) was seen in patients with abnormal CFR, with a most pronounced effect being observed in female patients free of myocardial ischemia (45.9 ± 34.9 vs 26.5 ± 18.0, p < 0.001 in women and 29.1 ± 16.9 vs 24.3 ± 21.7, p = 0.15 in men). Hence, a fully-adjusted multivariate logistic regression model identified HRR as the strongest negative predictor of reduced CFR in women free of myocardial ischemia, but not in men. Accordingly, receiver operating characteristics (ROC) curves for the presence of reduced CFR revealed that a %HRR <35 was a powerful predictor for abnormal CFR with a sensitivity of 81% and a specificity of 60% in women. Conclusion: A blunted HRR <35% is associated with abnormal CFR in women. Taking into account HR responses during stress test in women may help to risk stratify the heterogeneous female population of patients with non-obstructive coronary artery disease (CAD). [ABSTRACT FROM AUTHOR]

For improved prevention of health issues among blue-collar workers, there is a need for an overview of the physical activity at work and leisure using technical long-term measurements in blue-collar sectors investigation of differences between the sectors. Thus, the objective of this paper was to provide an overview and investigate differences in physical activities and body postures at work and leisure among blue-collar sectors. The Dphacto cohort consists of 1087 workers from manufacturing, transportation and cleaning sectors (901 blue-collar and 186 white-collar workers) in Denmark. Eligible workers provided physical activity and heart rate measurements over several days with follow-up on health-related outcomes by self-report and registers. Considerable differences in sitting, standing, time on feet (walking, shuffling and standing combined) and forward bending of the back were found between work and leisure, and between the sectors. This overview of physical activity at work and leisure can be useful for better prevention of work-related health issues among blue-collar workers. [ABSTRACT FROM AUTHOR]

It is important for construction companies to sustain a productive workforce without sacrificing its health and safety. This study aims to develop a practical judgement method to estimate the workload risk of individual construction workers. Based on studies, we developed a workload model comprising a hygrothermal environment, behavioral information, and the physical characteristics of workers). The construction workers’ heart rate and physical activity were measured using the data collected from a wearable device equipped with a biosensor and an acceleration sensor. This study is the first report to use worker physical activity, age, and the wet bulb globe temperature (WBGT) to determine a worker’s physical workload. The accuracy of this health risk judgment result was 89.2%, indicating that it is possible to easily judge the health risk of workers even in an environment where it is difficult to measure the subject in advance. The proposed model and its findings can aid in monitoring the health impacts of working conditions during construction activities, and thereby contribute toward determining workers’ health damage. However, the sampled construction workers are 12 workers, further studies in other working conditions are required to accumulate more evidence and assure the accuracy of the models.

مقدمه: عدم افزایش مناسب ضربان قلب متناسب با ورزش باعث پیش‌آگهی نامناسب بیماران قلبی می‌شود. علاوه بر این، سطوح فاكتورهای التهابی نظیر C-reactive protein با حساسیت بالا (hs-CRP یا High-sensitivity CRP) با آترواسكروز در ارتباط می‌باشد. در این مطالعه، این دو فاكتور در افراد با و بدون سندرم متابولیك بررسی شدند. روش‌ها: این مطالعه بر روی 123 بیمار با سندرم متابولیك و 203 بیمار بدون سندرم متابولیك كه به طور تصادفی از شركت كنندگان مطالعه‌ی كوهورت اصفهان انتخاب شده بودند، انجام گرفت. اطلاعات دموگرافیك، دور كمر، فشار خون، قد و وزن شركت كنندگان ثبت شد. سپس، سطح سرمی تری‌گلیسرید (Triglyceride یا TG)، قند ناشتای خون ( Fasting blood sugarیا FBS)، كلسترول تام (Total cholesterol یا TC)، لیپوپروتئین با چگالی بالا (High density lipoprotein یا HDL-c)، لیپوپروتئین با چگالی پایین (Low-density lipoprotein یا LDL-c) و hs-CRP اندازه‌گیری شد. تست ورزش بر اساس پروتكل استاندارد Bruce انجام گردید و ذخیره‌ی ضربات قلب (HRR یا Heart rate reserve) ثبت شد. اطلاعات با تنظیم بر اساس سن هر شركت كننده با استفاده از آزمون آماری Student’s t و رگرسیون خطی بررسی شد. یافته‌ها: متوسط سن در افراد با سندرم متابولیك 60/7 ± 29/54 و در افراد بدون سندرم متابولیك 61/8 ± 16/54 سال بود که تفاوت آماری معنی‌داری نداشت‌. در افراد با و بدون سندرم متابولیك به ترتیب میزان LDL-c برابر 55/29 ± 12/125 و 54/24 ± 17/116 میلی‌گرم بر دسی‌لیتر، میزان TG 49/184 ± 99/259 و 65/61 ± 38/140 میلی‌گرم بر دسی‌لیتر، میزان FBS برابر 46/48 ± 13/107 و 90/9 ± 81/81 میلی‌گرم بر دسی‌لیتر، میزان فشار خون سیستولیك برابر 15/15 ± 73/130 و 69/13 ± 06/116 میلی‌متر جیوه و میزان فشار خون دیاستولیك برابر 70/8 ± 84/28 و 69/6 ± 52/76 میلی‌متر جیوه بود و همه‌ی موارد از نظر آماری اختلاف معنی‌دار داشت. دو گروه از نظر ذخیره‌ی ضربان قلب تفاوت معنی‌داری نداشتند (027/0 = P) ولی میزان hs-CRP در گروه با سندرم متابولیك به وضوح بالاتر بود (02/0 = P). نتیجه‌گیری: ما در این مطالعه نتوانستیم ارتباطی بین ذخیره‌ی ضربات قلب و سندرم متابولیك نشان دهیم ولی ارتباط بین hs-CRP و سندرم متابولیك نشان‌دهنده‌ی افزایش میزان hs-CRP به عنوان یك فاكتور التهابی در افراد با سندرم متابولیك است.

Objectives: The aim of the study is to evaluate the intensity of the effort and energy expenditure in the course of performing selected classical massage techniques and to assess the workload of a massage therapist during a work shift.Material and Methods: Thirteen massage therapists (age: 21.9±1.9 years old, body mass index: 24.5±2.8 kg×m-2, maximal oxygen consumption × body mass-1 (VO2max×BM-1): 42.3±7 ml×kg-1×min-1) were involved in the study. The stress test consisted in performing selected classical massage techniques in the following order: stroking, kneading, shaking, beating, rubbing and direct vibration, during which the cardio-respiratory responses and the subjective rating of perceived exertion (RPE) were assessed. Intensity of exercise during each massage technique was expressed as % VO2max, % maximal heart rate (HRmax) and % heart rate reserve (HRR). During each massage technique, net energy expenditure (EE) and energy cost of work using metabolic equivalent of task (MET) were determined.Results: The intensity of exercise was 47.2±6.2% as expressed in terms of % VO2max, and 74.7±3.2% as expressed in terms of % HRmax, while it was 47.8±1.7% on average when expressed in terms of % HRR during the whole procedure. While performing the classical massage, the average EE and MET were 5.6±0.9 kcal×min-1 and 5.6±0.2, respectively. The average RPE calculated for the entire procedure was 12.1±1.4. During the performance of a classical massage technique for a single treatment during the study, the average total EE was 176.5±29.6 kcal, resulting in an energy expenditure of 336.2±56.4 kcal×h-1. In the case of the classical massage technique, rubbing was the highest intensity exercise for the masseur who performed the massage (%VO2max = 57.4±13.1%, HRmax = 79.6±7.7%, HRR = 58.5±13.1%, MET = 6.7±1.1, EE = 7.1±1.4 kcal×min-1, RPE = 13.4±1.3).Conclusions: In the objective assessment, physical exercise while performing a single classical massage is characterized by hard work. The technique of classical massage during which the masseur performs the highest exercise intensity is rubbing. According to the classification of work intensity based on energy expenditure, the masseur's work is considered heavy during the whole work shift. Int J Occup Med Environ Health 2018;31(5):677-684. [ABSTRACT FROM AUTHOR]

Objectives: We evaluated the prognostic value of heart rate reserve (ΔHR) and left ventricular ejection fraction reserve (ΔLVEF) among patients with systolic dysfunction. Background: Inadequate ΔHR (maximal stress HR - resting HR) and ΔLVEF (LVEF at stress - LVEF at rest) in response to stress are associated with adverse cardiac events. However, the significance of an abnormal ΔHR and ΔLVEF in patients with systolic dysfunction has not been described. Methods and results: We performed a retrospective analysis of patients with rest LVEF < 45% who underwent dipyridamole stress-rest gated Rb-82 PET myocardial perfusion imaging (PET-MPI) at the Cleveland Clinic between 2006 and 2009. Stress LVEF and volumes were calculated using commercially available software (4DM). A Cox proportional hazards model (CPH) was used to examine the association between ΔLVEF, ΔHR, and all-cause death (ACD). Among 461 patients (mean age 65.7 ± 11.3 years, 82% men) 167 experienced ACD (median follow-up 1045 days). Survival was reduced among patients with ΔHR < 0 (1090 vs. 1300 days, P = 0.04) and ΔLVEF < 0 (1002 vs. 1057 days, P = 0.03). In a CPH after adjusting for confounding variables, ΔHR ≤ 0 and ΔLVEF ≤ 0 were associated with reduced survival (hazard ratio 0.93, P < 0.01 and 0.84, P = 0.01, respectively) with an interaction between age and ΔHR (χ² = 8.1, P < 0.01). Our model predicts that the magnitude of ΔHR is associated with improved survival among younger patients. For any given ΔLVEF the magnitude of ΔHR has a greater positive effect on survival among younger patients. Conclusion: Both ΔHR and ΔLVEF during pharmacologic stress PET-MPI provide incremental value in predicting ACD among patients with systolic dysfunction. [ABSTRACT FROM AUTHOR]

Recent studies suggest that while leisure-time physical activity (LTPA) promotes general health, engaging in occupational physical activity (OPA) may have negative health consequences. It has been hypothesized that the different health effects from OPA and LTPA can be explained by differences in physical activity (PA) intensity in these two domains. To assess the intensity of OPA and LTPA, we aimed to study the percentage heart rate reserve (%HRR) during similar types of OPA and LTPA during workdays. Data from the NOMAD study on Danish blue-collar workers (n = 124) with objective measurements of PA (using accelerometers) and heart rate (using heart rate monitors) for 4 workdays were analysed. Activities of sitting, standing, moving, walking, and stair climbing were identified and %HRR in each of these activities was determined for work and leisure. %HRR was significantly higher during OPA than LTPA. These differences were more pronounced in men than in women. Although not statistically significant in the fully adjusted model, we found indications that these differences were more pronounced in those with low compared to high fitness. To our knowledge, this is the first study with objective measurements showing that %HRR is higher during the same gross-body postural activities when performed at work compared to leisure-time during workdays. This elevated intensity may help explaining the negative health consequences of engagement in high levels of OPA. Future guidelines should distinguish OPA from LTPA, possibly by advising workers to remain active during their leisure time, in particular when they are highly active at work. [ABSTRACT FROM AUTHOR]