Self-Rated Mental Stress and Exercise Training Response in Healthy Subjects

Purpose: Individual responses to aerobic training vary from almost none to a 40% increase in aerobic fitness in healthy subjects. We hypothesized that the baseline self-rated mental stress may influence to the training response. Methods: The study population included 44 healthy sedentary subjects (22 women) and 14 controls. The laboratory controlled training period was 2 weeks, including five sessions a week at an intensity of 75% of the maximum heart rate for 40 min/session. Self-rated mental stress was assessed by inquiry prior to the training period from 1 (low psychological resources and a lot of stressors in my life) to 10 (high psychological resources and no stressors in my life), respectively. Results: Mean peak oxygen uptake (VO2peak) increased from 34 ± 7 to 37 ± 7 ml kg−1 min−1 in training group (p < 0.001) and did not change in control group (from 34 ± 7 to 34 ± 7 ml kg−1 min−1). Among the training group, the self-rated stress at the baseline condition correlated with the change in fitness after training intervention, e.g., with the change in maximal power (r = 0.45, p = 0.002, W/kg) and with the change in VO2peak (r = 0.32, p = 0.039, ml kg−1 min−1). The self-rated stress at the baseline correlated with the change in fitness in both female and male, e.g., r = 0.44, p = 0.039 and r = 0.43, p = 0.045 for ΔW/kg in female and male, respectively. Conclusion: As a novel finding the baseline self-rated mental stress is associated with the individual training response among healthy females and males after highly controlled aerobic training intervention. The changes in fitness were very low or absent in the subjects who experience their psychological resources low and a lot of stressors in their life at the beginning of aerobic training intervention

Acute post-exercise change in blood pressure and exercise training response in patients with coronary artery disease

We tested the hypothesis that acute post-exercise change in blood pressure (BP) may predict exercise training responses in BP in patients with coronary artery disease (CAD). Patients with CAD (n=116, age 62±5 years, 85 men) underwent BP assessments at rest and during 10-min recovery following a symptom-limited exercise test before and after the 6-month training intervention (one strength and 3-4 aerobic moderate-intensity exercises weekly). Post-exercise change in systolic BP (SBP) was calculated by subtracting resting SBP from lowest post-exercise SBP. The training-induced change in resting SBP was -2±13 mmHg (p=0.064), ranging from -42 to 35 mmHg. Larger post-exercise decrease in SBP and baseline resting SBP predicted a larger training-induced decrement in SBP (β=0.46 and β=-0.44, respectively, p<0.001 for both). Acute post-exercise decrease in SBP provided additive value to baseline resting SBP in the prediction of training-induced change in resting SBP (R squared from 0.20 to 0.26, p=0.002). After further adjustments for other potential confounders (sex, age, baseline body mass index, realized training load), post-exercise decrease in SBP still predicted the training response in resting SBP (β=0.26, p=0.015). Acute post-exercise change in SBP was associated with training-induced change in resting SBP in patients with CAD, providing significant predictive information beyond baseline resting SBP

Heart rate dynamics after exercise in cardiac patients with and without type 2 diabetes

Purpose: The incidence of cardiovascular events is higher in coronary artery disease patients with type 2 diabetes (CAD+T2D) than in CAD patients without T2D. There is increasing evidence that the recovery phase after exercise is a vulnerable phase for various cardiovascular events. We hypothesized that autonomic regulation differs in CAD patients with and without T2D during post-exercise condition. Methods: A symptom-limited maximal exercise test on a bicycle ergometer was performed for 68 CAD+T2D patients (age 61 &#177; 5 years, 78% males, ejection fraction 67 &#177; 8, 100% on β-blockade) and 64 CAD patients (age 62 &#177; 5 years, 80% males, ejection fraction 64 &#177; 8, 100% on β-blockade). Heart rate (HR) recovery after exercise was calculated as the slope of HR during the first 60 sec after cessation of exercise (HRRslope). R-R intervals were measured before (5 min) and after exercise from 3 to 8 min, both in a supine position. R-R intervals were analyzed using time and frequency methods and a detrended fluctuation method (α1). Results: BMI was 30 &#177; 4 vs. 27 &#177; 3 kg•m2 (p &lt; 0.001); maximal exercise capacity, 6.5 &#177; 1.7 vs. 7.7 &#177; 1.9 METs (p &lt; 0.001); maximal HR, 128 &#177; 19 vs. 132 &#177; 18 bpm (p = ns); and HRRslope, -0.53 &#177; 0.17 vs. -0.62 &#177; 0.15 beats/sec (p = 0.004), for CAD patients with and without T2D, respectively. There was no differences between the groups in HRRslope after adjustment for METs, BMI and medication (ANCOVA, p = 0.228 for T2D and e.g. p = 0.030 for METs). CAD+T2D patients had a higher HR at rest than nondiabetic patients (57 &#177; 10 vs. 54 &#177; 6 bpm, p = 0.030), but no other differences were observed in HR dynamics at rest or in post-exercise condition. Conclusion: HR recovery is delayed in CAD+T2D patients, suggesting impairment of vagal activity and/or augmented sympathetic activity after exercise. Blunted HR recovery after exercise in diabetic patients compared with nondiabetic patients is more closely related to low exercise capacity and obesity than to T2D itself

Impact and management of physiological calibration in spectral analysis of blood pressure variability

Physiological calibration (Physiocal) improves the quality of continuous blood pressure (BP) signal from finger. However, the effects of Physiocal on spectral characteristics of systolic BP (SBP) variability are not well-known. We tested the hypothesis that the use of Physiocal may alter the results on SBP variability when compared with BP recording without Physiocal. Continuous BP was recorded simultaneously from fingers of both arms during 10-min standing by two Nexfin devices, one with (ON) and the other without (OFF) Physiocal (n=19). Missing SBP values in ON signal were linearly interpolated over Physiocal sequences (ON_inter). The OFF signal was analyzed without any corrections (OFF_reference) and after linear interpolation of corresponding sequences when Physiocal appeared in the ON signal (OFF_inter). Mean low frequency power of SBP oscillations (LF_SBP, 0.04-0.15 Hz) did not differ between the OFF_reference, OFF_inter and ON_inter. However, LF_SBP deviated more from OFF_reference when analysed from ON_inter compared with the analysis from OFF_inter (median [interquartile range]: 14.7 [4.6-38.6] vs. 0.9 [0.5-1.8] %, p<0.05). In conclusion, the use of Physiocal had a significant effect on the spectral SBP variability that overwhelms the impact of linear interpolation of short data sequences. Therefore, caution is needed when comparing SBP variability between BP datasets acquired with and without Physiocal

Peak exercise capacity prediction from a submaximal exercise test in coronary artery disease patients

The purpose of this study was to determine whether a rating of perceived exertion scale (RPE) obtained during submaximal exercise could be used to predict peak exercise capacity (METpeak) in coronary artery disease (CAD) patients. Angiographically documented CAD patients (n = 124, 87% on β blockade) completed a symptom-limited peak exercise test on a bicycle ergometer, reporting RPE values at every second load on a scale of 6 to 20. Regression analysis was used to develop equations for predicting METpeak. We found that submaximal METs at a workload of 60/75 W (for women and men, respectively) and the corresponding RPE (METs/RPE ratio) was the most powerful predictor of METpeak (r = 0.67, p &lt; 0.0001). The final model included the submaximal METs/RPE ratio, body mass index, sex, resting heart rate, smoking history, age, and use of a β blockade (r = 0.86, p &lt; 0.0001, SEE 0.98 METs). These data suggest that RPE at submaximal exercise intensity is related to METpeak in CAD patients. The model based on easily measured variables at rest and during warm-up exercise can reasonably predict absolute METpeak in patients with CAD

Unobtrusive, Low-Cost Out-of-Hospital, and In-Hospital Measurement and Monitoring System

Continuous monitoring of vital signs can be a life-saving matter for different patient groups. The development is going toward more intelligent and unobtrusive systems to improve the usability of body-worn monitoring devices. Body-worn devices can be skin-conformable, patch-type monitoring systems that are comfortable to use even for prolonged periods of time. Herein, an intelligent and wearable, out-of-hospital, and in-hospital four-electrode electrocardiography (ECG) and respiration measurement and monitoring system is proposed. The system consists of a conformable screen-printed disposable patch, a measurement unit, gateway unit, and cloud-based analysis tools with reconfigurable signal processing pipelines. The performance of the ECG patch and the measurement unit was tested with cardiac patients and compared with a Holter monitoring device and discrete, single-site electrodes.publishedVersionPeer reviewe

Unobtrusive, low‐cost out‐of‐hospital, and in‐hospital measurement and monitoring system

Abstract Continuous monitoring of vital signs can be a life‐saving matter for different patient groups. The development is going toward more intelligent and unobtrusive systems to improve the usability of body‐worn monitoring devices. Body‐worn devices can be skin‐conformable, patch‐type monitoring systems that are comfortable to use even for prolonged periods of time. Herein, an intelligent and wearable, out‐of‐hospital, and in‐hospital four‐electrode electrocardiography (ECG) and respiration measurement and monitoring system is proposed. The system consists of a conformable screen‐printed disposable patch, a measurement unit, gateway unit, and cloud‐based analysis tools with reconfigurable signal processing pipelines. The performance of the ECG patch and the measurement unit was tested with cardiac patients and compared with a Holter monitoring device and discrete, single‐site electrodes