Monitoring Performance in Show Jumping Horses: Validity of Non-specific and Discipline-specific Field Exercise Tests for a Practicable Assessment of Aerobic Performance

Show jumping is a highly specialized equestrian discipline that requires technical skill but also power and fitness. Monitoring the horses’ aerobic performance is therefore essential in order to verify whether the training has induced the desired cardiovascular and muscular adaptations. This study therefore aimed at evaluating the validity of non-specific and discipline-specific field exercise tests for objective evaluation of aerobic performance in show jumpers. For this purpose, data obtained from horses competing at Junior and Young Rider level during show jumping competitions as well as field exercise tests were retrospectively analyzed. The effect of the level of difficulty, the horses’ age, the penalty score and the horses’ previous level of performance on blood lactate concentrations after show jumping competitions (100 observations in 49 horses) was evaluated by linear mixed effects models (horse as random effect). Estimated marginal means significantly increased from 140 (4.1 mmol/L) to 150 cm (5.2 mmol/L) classes (P = 0.02). Furthermore, post-exercise lactate values significantly increased with the horses’ age (P = 0.001). Another group of 12 horses performed a standardized incremental field exercise test on a track (SETtrack), a standardized show jumping course (SETcourse) and a standardized grid exercise (SETgrid) each on three consecutive days. Indices of aerobic performance, derived from the SETtrack [velocity at a heart rate of 140 bpm (V140) and at a lactate concentration of 2 mmol/L (VLa2)] were highly correlated with heart rate (V140: r = −0.75, P = 0.005; VLa2: r =−0.66, P = 0.02) and lactate (V140: r = −0.73, P = 0.02; VLa2: r = −0.72, P = 0.02) in response to SETcourse as well as heart rate during SETgrid (V140: r = −0.73, P = 0.02; VLa2: r = −0.76, P = 0.01). Subjective rating of muscular fatigue was significantly correlated to the mean heart rate during SETcourse (r = −0.64, P = 0.05) and SETgrid (r = −0.74, P = 0.02) but not to the aerobic indices calculated from SETtrack. Besides non-specific incremental field tests, performance monitoring in show jumpers should therefore also include discipline-specific tests that more closely reflect the internal load induced by show jumping competitions.

Performance and Recovery of Well-Trained Younger and Older Athletes during Different HIIT Protocols

Due to physiological and morphological differences, younger and older athletes may recover differently from training loads. High-intensity interval training (HIIT) protocols are useful for studying the progression of recovery. It was the objective of this study to determine age differences in performance and recovery following different HIIT protocols. Methods: 12 younger (24.5 ± 3.7 years) and 12 older (47.3 ± 8.6 years) well-trained cyclists and triathletes took part in this study. Between the age groups there were no significant differences in relative peak power to fat-free mass, maximal heart rate (HR), training volume, and VO2max-percentiles (%). Participants performed different HIIT protocols consisting of 4 × 30 s Wingate tests with different active rest intervals (1, 3, or 10 min). Peak and average power, lactate, HR, respiratory exchange ratio (RER), subjective rating of perceived exertion (RPE), and recovery (Total Quality Recovery scale, TQR) were assessed. Results: During the different HIIT protocols, metabolic, cardiovascular, and subjective recovery were similar between the two groups. No significant differences were found in average lactate concentration, peak and average power, fatigue (%), %HRmax, RER, RPE, and TQR values between the groups (p > 0.05). Conclusion: The findings of this study indicate that recovery following HIIT does not differ between the two age groups. Furthermore, older and younger participants displayed similar lactate kinetics after the intermittent exercise protocols.

A Novel Approach for More Effective Emergency Equipment Storage: The Task-Based Package-Organized Neonatal Emergency Backpack

Objectives: To evaluate a new task-based package-organized (TPO) neonatal emergency backpack and to compare it to the classical (ABC- and material-based) backpack.Methods: Simulation-based assessment of time to retrieve equipment for three different tasks [intraosseous access (IO), intubation and adrenaline administration] using the TPO and the classical emergency backpack was compared.Results: Equipment retrieval times for the three tasks were assessed for 24 nurses (12 intermediate care, 12 intensive care) and were significantly faster in the TPO than in the classical backpack (IO 33 vs. 75 s, p < 0.001; intubation 53 vs. 70 s, p = 0,001; adrenaline 22 vs. 45 s, p < 0.001). The number of missing items was significantly lower using the TPO backpack for IO and adrenaline retrieval (IO 0,9 vs. 2,3 items, p < 00001, adrenaline 0.04 vs. 1, p < 0.001) but not for intubation equipment (0.9 vs. 1, not significant). The subjective rating of overall clearness was significantly higher for the TPO compared with the classical backpack (5,9 vs. 3,5, p < 0.001).Conclusion: Task-based package organization of neonatal emergency backpacks is feasible and might be superior to ABC-/material-oriented storage.

Comfort Evaluation of Slow-Recovery Ejection Seat Cushions Based on Sitting Pressure Distribution

Sitting discomfort not only affects the health of pilots carrying out long-endurance missions but also affects operational performance. The experimental objects included four ejection seat cushions: N1 was a fast-recovery foam as the comparison group, and the experimental groups were slow-recovery foams with different indentation force deflection (IFD), named N2 (hard), N3 (mid), and N4 (soft). The sitting comfort of 20 participants was tested on the four cushions by using subjective rating and sitting pressure distribution analysis. The results showed that compared with fast-recovery cushion N3 and N4 slow-recovery cushions have lower contact pressure and more uniform pressure distribution. Slow-recovery cushions that were too soft or too hard would reduce the comfort. No matter from the subjective rating or the analysis of the contact pressure data, the N3 cushion with a thickness of 3 cm and 65% IFD of 280 N had the highest comfort. In addition, the seat pressure distribution (SPD%) has a significant correlation with the subjective rating (p = 0.019, R = −0.98), which is more suitable for evaluating the comfort of the cushions. However, the slow-recovery cushions would show a decrease in support after a period of sitting, while the fast-recovery cushion could always maintain constant support.

Experimental study of standing and walking at work — What is compatible with physiological characteristics and human needs?

An experimental study with two scenarios S1 and S2 was conducted, in which the standing and walking proportions as well as movement dynamics were varied. Eleven participants have taken part in the study for 2.5 h each (cycle time: 90 s). By means of surface electromyography, the static and dynamic components of muscle strain as well as the muscle fatigue were recorded and compared with the results of water plethysmography and a structured subjective rating survey. The results of the EMG study showed significantly higher dynamic components of the EA at S2 compared to S1, while the static components for the same activities did not show any significant difference, as expected. S1 and S2 always led to an increase in volume of the lower leg. Standing with less walking (S1) resulted in a significantly higher increase than standing with a higher proportion of walking and stronger dynamic movements (S2). In scenario S2, compared to scenario S1, the participants reported weaker subjective complaints which were also reported later in time. The results on muscular fatigue indicated only partially significant differences between S1 and S2. The results make clear that the dynamics of movement are a decisive criterion for assessing standing activities.Practical Relevance: To relieve strain during standing work, “real” walking movement must be integrated into the workflow. It could be shown that only a small step to the side or a few “shuffling” steps are not sufficient. In contrast, it is compatible with human physiological characteristics to make correct steps and dynamically activate the leg muscles.

Research on Discrimination Threshold of Brightness for Different Color Temperatures

This article explores the experimental study on the relationship between human eye discrimination threshold of white light under different lighting levels and color temperatures by the psychophysical experimental method. The visual matching method was applied to study the subjective brightness perception under different lighting environments. We try to explore the internal connection between the physical intensity and subjective rating value. The experimental results will do help the development of dimming system for smart lighting.

Default mode and frontal executive network interactions enable interoceptive attention & mindfulness

Interoceptive attention to internal sensory signals is fundamental to mindfulness. In an attention-to-breathing task in 161 adults, we found that consistency of interoceptive attention significantly correlated with performance efficiency across several exteroceptive cognitive domain tasks. EEG source mapping within subjects showed that on low-consistency or distracted trials there was greater recruitment of frontal executive control activity in the dorsolateral prefrontal cortex (DLPFC) and suppression of the posterior default mode network (Precuneus), with increased functional connectivity between these regions. In contrast, high-consistency or attentive trials were associated with greater connectivity between Anterior Cingulate Cortex (ACC) and Insula, key nodes of the cognitive control network for attention monitoring. Notably, individual trait mindfulness was correlated with greater functional connectivity between DLPFC-Precuneus on distracted trials and greater ACC-Insula connectivity on attentive trials. These results showcase dynamic network interactions underlying objective markers of interoceptive attention and subjective rating mindfulness.

The Influence of Hydrated Lime and Cellulose Ether Admixture on Water Retention, Rheology and Application Properties of Cement Plastering Mortars

In this article, the effect of hydrated lime and cellulose ether on the water retention, rheology, and application properties of plasters was studied. For mortars, the consistency, bulk density, and water retention were tested. Rheological measurements of pastes included yield stress and plastic viscosity. In addition to standard tests of mortars and examining the rheological properties of the pastes, a proprietary method for testing the application properties was proposed. The obtained research results made it possible to evaluate the performance of the tested plasters. An attempt was also made to correlate the rheological properties of pastes (plastic viscosity) to the water retention value. The influence of hydrated lime and cellulose ether on selected properties of pastes and plasters was also presented using the statistical Box–Behnken method. The subjective rating of an expert plasterer confirmed the necessity of the modification of plastering mortars with hydrated lime and cellulose ether. As shown, modification of cement plastering mortar with hydrated lime and cellulose ether at the same time allows obtaining a material with favorable technical and technological properties, especially mortars applied by machine.

Measuring Cognitive Load: Are There More Valid Alternatives to Likert Rating Scales?

Cognitive load researchers have used varying subjective techniques based on rating scales to quantify experienced cognitive load. Although it is generally assumed that subjects can introspect on their cognitive processes and have no difficulty in assigning numerical values to the imposed cognitive load, little is known about how visual characteristics of the rating scales influence the validity of the cognitive load measure. In this study we look at validity of four subjective rating scales (within groups) differing in visual appearance by participants rating perceived difficulty and invested mental effort in response to working on simple and complex weekday problems. We used two numerical scales (the nine-point Likert scale most often used in Cognitive load theory research and a Visual Analogue Scale ranging between 0–100%) and two pictorial scales (a scale consisting of emoticons ranging from a relaxed blue-colored face to a stressed red-colored face and an “embodied” scale picturing nine depicted weights from 1–9 kg). Results suggest that numerical scales better reflect cognitive processes underlying complex problem solving while pictorial scales Underlying simple problem solving. This study adds to the discussion on the challenges to quantify cognitive load through various measurement methods and whether subtleties in measurements could influence research findings.