Rating Of Perceived Effort Research Articles

Delaying post-exercise carbohydrate intake impairs next-day exercise capacity but not muscle glycogen or molecular responses.

To investigate how delayed post-exercise carbohydrate intake affects muscle glycogen, metabolic- and mitochondrial-related molecular responses, and subsequent high-intensity interval exercise (HIIE) capacity. In a double-blind cross-over design, nine recreationally active men performed HIIE (10 × 2-min cycling, ~94% W˙peak) in the fed state, on two occasions. During 0-3 h post-HIIE, participants drank either carbohydrates ("Immediate Carbohydrate" [IC], providing 2.4 g/kg) or water ("Delayed Carbohydrate" [DC]); total carbohydrate intake over 24 h post-HIIE was matched (~7 g/kg/d). Skeletal muscle (sampled pre-HIIE, post-HIIE, +3 h, +8 h, +24 h) was analyzed for whole-muscle glycogen and mRNA content, plus signaling proteins in cytoplasmic- and nuclear-enriched fractions. After 24 h, participants repeated the HIIE protocol until failure, to test subsequent HIIE capacity; blood lactate, heart rate, and ratings of perceived effort (RPE) were measured throughout. Muscle glycogen concentrations, and relative changes, were similar between conditions throughout (p > 0.05). Muscle glycogen was reduced from baseline (mean ± SD mmol/kg dm; IC: 409 ± 166; DC: 352 ± 76) at post-HIIE (IC: 253 ± 96; DC: 214 ± 82), +3 h (IC: 276 ± 62; DC: 269 ± 116) and + 8 h (IC: 321 ± 56; DC: 269 ± 116), returning to near-baseline by +24 h. Several genes (PGC-1ɑ, p53) and proteins (p-ACCSer79, p-P38 MAPKThr180/Tyr182) elicited typical exercise-induced changes irrespective of condition. Delaying carbohydrate intake reduced next-day HIIE capacity (5 ± 3 intervals) and increased RPE (~2 ratings), despite similar physiological responses between conditions. Molecular responses to HIIE (performed in the fed state) were not enhanced by delayed post-exercise carbohydrate intake. Our findings support immediate post-exercise refueling if the goal is to maximize next-day HIIE capacity and recovery time is ≤24 h.

Impact of Weekly Training-Load Structure and Content on the Risk of Injury in Professional Rugby Union Match-Play.

Chéradame, J, Loursac, R, Piscione, J, Carling, C, Decq, P, and Jacqmin-Gadda, H. Impact of weekly training-load structure and content on the risk of injury in professional Rugby Union match-play. J Strength Cond Res 38(9): 1613-1619, 2024-The aim of this study was to investigate the impact of different components of daily training load during the week preceding the match on the risk of sustaining a match injury in professional rugby union. A cohort of 72 players from a single professional French club participated. Global positioning system-derived data including total distance (TD) and high-speed distance in addition to ratings of perceived effort (RPE) for both on- and off-pitch (gym-based strength conditioning work) training were collected for each training session over 3 seasons (2017-2020). The association between the daily measures of external and internal training load over the week preceding the day of the match (MD) and the subsequent risk of injury in match-play was estimated using a mixed-effects logistic model adjusted for contextual and individual factors. A total of 184 injuries were sustained in 128 matches (incidence: 81.2 injuries per 1,000 player hours). Higher RPE values for the strength conditioning session on MD-5 ( p < 0.001) and for the on-pitch session on MD-1 ( p = 0.04) were associated with an increased risk of injury in matches. On MD-2, a higher TD covered and that run at high speed (>MAS) were, respectively, associated with a higher ( p = 0.03) and lower risk ( p = 0.02) of injury in matches played. This study in professional rugby union shows that different components of external and internal load had varying influences on injury risk and particularly in relation to the day on which these were performed in the week leading up to the next match. At MD-2, training load favoring intensity rather than volume could reduce the risk of match-play injury.

Sleep deprivation increases the regularity of isometric torque fluctuations

The regularity of the fluctuations present in torque signals represent the adaptability of the motor control. While previous research showed how it is affected by neuromuscular fatigue and ageing, the underlying mechanisms remain unclear. It is currently under debate whether these changes are explained by central or peripheral neuromuscular mechanisms. Here, we experimentally manipulated the sleep of thirteen young adults through a supervised 24 h-sleep deprivation protocol. This study aimed to investigate the effect of sleep deprivation on the regularity of torque fluctuations, and other standard torque-related outcomes (Peak Torque – PT – and Rate of Torque Development – RTD). The participants were asked to perform knee extension maximal voluntary contractions (MVC) and submaximal knee extensions at 40% of MVC for 30 s. PT and RTD were calculated from the MVC and the regularity of the torque fluctuations was determined on the submaximal task through Sample Entropy (SampEn). In addition, rate of perceived effort (RPE) was collected. We found no significant changes in PT and RTD. The regularity of torque fluctuations significantly increased (i.e., a decrease in SampEn) after 24 h-sleep deprivation (PRE = 1.76 ± 0.268, POS24 = 1.71 ± 0.306; p = 0.044). Importantly, we found a negative correlation between RPE and SampEn relative changes after sleep deprivation. This study brings new insights towards the understanding of the underlying mechanisms that explain changes in torque fluctuations, demonstrating that these changes are not limited to neuromuscular processes but are also likely to be affected by other domains, such as psychological profile, which can indirectly affect the neural drive to the muscles.

No Differences in Exercise Performance, Perceptual Response, or Safety Were Observed Among 3 Blood Flow Restriction Devices

To compare 3 separate blood flow restriction (BFR) systems in their capacity to reduce repetitions to failure, impact perceptual responses, and cause adverse events during a low-load free-flow exercise. The study included healthy subjects aged 18 years or older who presented to an ambulatory-care sports medicine clinic. On day 1, participants' demographic characteristics and anthropomorphic measurements were recorded. Each participant performed dumbbell biceps curl repetitions to failure using 20% of his or her 1-repetition maximum weight with each arm. Participants were exposed to 3 different tourniquet systems for familiarization. On day 2, each participant's arm was randomized to a cuff system, and the participant performed 2 sets of biceps curl repetitions to failure with the cuff inflated. Repetitions to failure, rating of perceived effort (RPE), rating of perceived discomfort, and pulse oxygenation levels were recorded after each set. On day 3, participants completed a survey of their perceived delayed-onset muscle soreness. The final analysis was performed on 42 arms, with 14 limbs per system. The study population had a mean age of 28.7 ± 2.4 years and a mean body mass index of 24.9 ± 4.3. All 3 systems successfully reduced repetitions to failure compared with unrestricted low-load exercise from baseline to BFR set 1 and from baseline to BFR set 2. There were no significant between-group differences among BFR systems regarding the number of repetitions to failure performed at baseline versus BFR set 1 or BFR set 2. The Delfi Personalized Tourniquet System (PTS) cohort had the greatest reductions in repetitions to failure from BFR set 1 to BFR set 2 (P= .002) and reported the highest RPE after set 2 (P= .025). The Delfi PTS, SmartCuffs Pro, and BStrong BFR systems were each safe and were able to significantly reduce repetitions to failure compared with a low-load free-flow condition when used in a BFR exercise protocol. The Delfi PTS system may produce a higher RPE with prolonged use in comparison to the other systems. Level II, prospective cohort study.

Prediction of instantaneous perceived effort during outdoor running using accelerometry and machine learning.

The rate of perceived effort (RPE) is a subjective scale widely used for defining training loads. However, the subjective nature of the metric might lead to an inaccurate representation of the imposed metabolic/mechanical exercise demands. Therefore, this study aimed to predict the rate of perceived exertions during running using biomechanical parameters extracted from a commercially available running smartwatch. Forty-three recreational runners performed a simulated 5-km race on a track, providing their RPE from a Borg scale (6-20) every 400 m. Running distance, heart rate, foot contact time, cadence, stride length, and vertical oscillation were extracted from a running smartwatch (Garmin 735XT). Machine learning regression models were trained to predict the RPE at every 5 s of the 5-km race using subject-independent (leave-one-out), as well as a subject-dependent regression method. The subject-dependent method was tested using 5%, 10%, or 20% of the runner's data in the training set while using the remaining data for testing. The average root-mean-square error (RMSE) in predicting the RPE using the subject-independent method was 1.8 ± 0.8 RPE points (range 0.6-4.1; relative RMSE ~ 12 ± 6%) across the entire 5-km race. However, the error from subject-dependent models was reduced to 1.00 ± 0.31, 0.66 ± 0.20 and 0.45 ± 0.13 RPE points when using 5%, 10%, and 20% of data for training, respectively (average relative RMSE < 7%). All types of predictions underestimated the maximal RPE in ~ 1 RPE point. These results suggest that the data accessible from commercial smartwatches can be used to predict perceived exertion, opening new venues to improve training workload monitoring.

Relationship between rolling resistance, preferred speed, and manual wheelchair propulsion mechanics in non-disabled adults

Purpose To characterize the relationship among rolling resistance (RR), preferred speed, and propulsion mechanics. Methods N = 11 non-disabled individuals (mean (SD)); Age 24 years (2), BMI 23.8 kg/m2 (4.3) completed a submaximal graded wheelchair exercise test (GXTsubmax, fixed speed, terminated at Rating of Perceived Effort (RPE)=8 (0-10 scale)) and a single-blind, within-subject repeated measures wheelchair propulsion experiment (RME). RR at RPE = 10 (estimated maximum workload, Maxestimated) was estimated from the GXTsubmax RPE-RR relationship. RME consisted of N = 19 1-minute trials (self-selected speed) each followed by 2-minutes rest. The trials included N = 16 unique RR between 25-100% of Maxestimated. Averages of all pushes in N = 16 unique 1-minute trials were computed for average RR (N), speed (m/s), peak force (Fpeak (N)), force rate of rise (Fror (N/s)), push frequency (PF (pushes/min)), and push length (PL (deg)). Results Repeated measures correlation assessed relationships among outcome variables (α = 0.05). RR was associated with decreased speed (r=–0.81, p < 0.001), increased Fpeak (r = 0.92), Fror (r = 0.26), and PL (r = 0.32) (all p > 0.001), and unrelated to PF (r = 0.02, p = 0.848). Increased speed was associated with increased Fror (r = 0.23, p = 0.003) and PF (r = 0.27, p < 0.001) and decreased Fpeak (r=–0.66, p < 0.001) and PL (r=-0.25, p < 0.001). Conclusion Increasing RR increases Fpeak despite reducing self-selected speed. RR and speed were strongly and moderately related to Fpeak, respectively, but weakly related to other propulsion mechanics. These results suggest that reducing user-system RR may confer dual benefits of improved mobility and decreased upper extremity loading. Further testing among wheelchair users is required. Clinical trial registration number: NCT04987177

Analysis of Heart Rate, Perception of Physical Effort and Performance of Individuals with Down Syndrome Submitted to a Protocol of Virtual Games for Home-Based Telerehabilitation

Down syndrome (DS) is a genetic condition associated with impairments in several body systems, which may negatively influence the habit of practicing physical activities (PAs), increasing sedentary habits and the risk of comorbidities. Additionally, difficulty in accessing services, financial limitations and lack of interest may interfere with the practice of PAs. Considering the necessity of developing effective treatment alternatives, to increase the possibility of access and the interest of participants, we conducted a study using telerehabilitation with a virtual task to promote PA and analyze the motor performance of DS individuals. Our protocol consisted of 11 sessions of the virtual game called MoveHero. A total of 34 individuals with DS and 34 individuals with typical development participated in the study. Heart rate (HR) and rating of perceived effort (RPE) were collected at rest and during the game. Our results show that virtual reality presents a great possibility to promote PA and a way out of a sedentary lifestyle for DS individuals, considering the enhancement in HR and RPE found during the protocol for both groups. Moreover, our results show positive outcomes regarding motor performance, with significant improvement in the task with practice, demonstrating that individuals with DS are able to improve their motor proficiency with adequate stimuli in the virtual environment.

Rating of perceived effort but relative to what? A comparison between imposed and self-selected anchors

PurposeCollecting reliable and valid rating of perceived effort (RPE) data requires properly anchoring the scales’ upper limits (i.e., the meaning of 10 on a 0–10 scale). Yet, despite their importance, anchoring procedures remain understudied and theoretically underdeveloped. Here we propose a new task-based anchoring procedure that distinguishes between imposed and self-selected anchors. In the former, researchers impose on participants a specific task as the anchor; in the latter, participants choose the most effortful task experienced or imaginable as the anchor. We compared the impact of these conceptually different anchoring procedures on RPE. MethodsTwenty-five resistance-trained participants (13 females) attended a familiarization and two randomized experimental sessions. In both experimental sessions, participants performed non-fatiguing and fatiguing isometric maximal voluntary contraction (MVC) protocols with the squat followed by the gripper or vice versa. After each MVC, participants reported their RPE on a 0–10 scale relative to an imposed anchor of the performed task (e.g., gripper MVCs anchored to a gripper MVC) or to a self-selected anchor. ResultsIn the non-fatiguing condition, imposed anchors yielded greater RPEs than self-selected anchors for both the squat [on average, 9.4 vs. 5.5; Δ(CI95%) = 3.9 (3.2, 4.5)] and gripper [9.4 vs. 3.9; Δ = 5.5 (4.7, 6.3)]. Similar results were observed in the fatiguing condition for both the squat [9.7 vs. 6.9; Δ = 2.8 (2.1, 3.5)] and gripper [9.7 vs. 4.5; Δ = 5.2 (4.3, 5.9)]. ConclusionsWe found large differences in RPE between the two anchors, independent of exercises and fatigue state. These findings provide a basis for further development and refinement of anchoring procedures and highlight the importance of selecting, justifying, and consistently applying the chosen anchors.

Investigating the autoregulation of applied blood flow restriction training pressures in healthy, physically active adults: an intervention study evaluating acute training responses and safety

ObjectiveTo examine the effects of autoregulated (AUTO) and non-autoregulated (NAUTO) blood flow restriction (BFR) application on adverse effects, performance, cardiovascular and perceptual responses during resistance exercise.MethodsFifty-six healthy participants underwent AUTO...

Test–retest reliability of a 30-min fixed perceived effort cycling exercise

PurposeUsing exercise protocols at a fixed rating of perceived effort (RPE) is a useful method for exploring the psychophysical influences on exercise performance. However, studies that have employed this protocol have arbitrarily selected RPE values without considering how these values correspond to exercise intensity thresholds and domains. Therefore, aligning RPE intensities with established physiological thresholds seems more appropriate, although the reliability of this method has not been assessed. MethodsEight recreationally active cyclists completed two identical ramped incremental trials on a cycle ergometer to identify gas exchange threshold (GET). A linear regression model plotted RPE responses during this test alongside gas parameters to establish an RPE corresponding to GET (RPEGET) and 15% above GET (RPE+15%GET). Participants then completed three trials at each intensity, in which performance, physiological, and psychological measures were averaged into 5-min time zone (TZ) intervals and 30-min ‘overall’ averages. Data were assessed for reliability using intraclass correlation coefficients (ICC) and accompanying standard error measurements (SEM), 95% confidence intervals, and coefficient of variations (CoV). Results All performance and gas parameters showed excellent levels of test–retest reliability (ICCs = > .900) across both intensities. Performance, gas-related measures, and heart rate averaged over the entire 30-min exercise demonstrated good intra-individual reliability (CoV = < 5%). ConclusionRecreationally active cyclists can reliably replicate fixed perceived effort exercise across multiple visits when RPE is aligned to physiological thresholds. Some evidence suggests that exercise at RPE+15%GET is more reliable than RPEGET.

Prescribing Intensity in Resistance Training Using Rating of Perceived Effort: A Randomized Controlled Trial.

Introduction: Rating of perceived effort (RPE) scales are used to prescribe intensity in resistance training (RT) in several ways. For instance, trainees can reach a specific RPE value by modifying the number of repetitions, lifted loads, or other training variables. Given the multiple approaches of prescribing intensity using RPE and its growing popularity, we compared the effects of two RPE prescription approaches on adherence rates, body composition, performance and psychological outcomes, in an online RT intervention. Methods: We randomly assigned 57 healthy participants without RT experience (60% females, age range: 18–45) to one of two groups that received two weekly RT sessions using a resistance-band for 8 weeks. In the fixed-repetition group, participants adjusted the band resistance with the goal of completing 10 repetitions and reaching a 7-RPE on a 0–10 scale by the 10th repetition. In the open-repetition group, participants selected their preferred band resistance and completed repetitions until reaching a 7-RPE by the final repetition. We measured body composition, performance, and program satisfaction rates. Results: We assessed 46 participants at post-test, 24 from the fixed-repetition group and 22 from the open-repetition group. We observed non-significant and trivial differences between groups in all outcomes (p > 0.05). We then combined the pre-post change scores of the two groups. We found that adherence rates began at 89% and gradually decreased to 42%. On average, participants increased their fat-free mass [0.3 kg (95% CI: 0.1–0.6)], isometric mid-thigh pull [5.5 kg (95% CI: 0.8–10.4)], isometric knee-extension [2.2 kg (95% CI: 0.8–3.7)], and push-ups [6.3 repetitions (95% CI: 4.5–8.2)]. We observed non-significant and trivial changes in bodyweight, grip-force, and countermovement jump. Participants reported high satisfaction rates with all components of the program. Conclusion: Participants in both groups improved their body composition and physical capacity to a similar extent, and reported comparable satisfaction rates with the programs they followed. Accordingly, either prescription approach can be used to deliver online RT sessions based on personal preferences and logistical constraints. However, since adherences rates declined over the course of the study, future research should test additional strategies aiming to maintain adherence rates.

Should We Trust Perceived Effort for Loading Control and Resistance Exercise Prescription After ACL Reconstruction?

The rating of perceived effort (RPE) is a common method used in clinical practice for monitoring, loading control, and resistance training prescription during rehabilitation after rupture and anterior cruciate ligament reconstruction (ACLR). It is suggested that the RPE results from the integration of the afferent feedback and corollary discharge in the motor and somatosensory cortex, and from the activation of brain areas related to emotions, affect, memory, and pain (eg, posterior cingulate cortex, precuneus, and prefrontal cortex). Recent studies have shown that rupture and ACLR induce neural adaptations in the brain commonly associated with the RPE. Therefore, we hypothesize that RPE could be affected because of neural adaptations induced by rupture and ACLR. Clinical review. Level 5. RPE could be directly altered by changes in the activation of motor cortex, posterior cingulate cortex, and prefrontal cortex. These neural adaptations may be induced by indirect mechanisms, such as the afferent feedback deficit, pain, and fear of movement (kinesiophobia) that patients may feel after rupture and ACLR. Using only RPE for monitoring, loading control, and resistance training prescription in patients who had undergone ACLR could lead to under- or overdosing resistance exercise, and therefore, impair the rehabilitation process. 3C.

Effects of FFP2/N95 face mask on low- and high-load resistance exercise performance in recreational weight lifters

ABSTRACT The objective of this study was to verify the acute effects of an FFP2/N95 face mask on moderate- and high-load resistance exercise performance in recreational weight lifters. Seventeen recreational weight lifters performed four randomized bouts: high intensity [70% of one maximum repetition (1RM)] and moderate intensity (50% 1RM), both with and without an FFP2/N95 face mask. All sequences of exercises were performed over four sets in the bench press exercise, performed on a Smith machine until movement failure, with two minutes of recovery between sets. A linear position transducer was used to measure the bar velocity, and record the mean propulsive velocity (MPV) and maximum propulsive velocity (V max). The rate of perceived effort (RPE), heart rate (HR), blood pressure, and oxygen saturation (SpO2) were recorded. For the high-intensity condition, MPV (p = 0.021) and V max (p = 0.004) were significantly lower in the mask condition compared to non-mask in set-1, however, there were no significant differences for moderate intensity or for total volume in either intensity (p > 0.05). There was a significant difference between conditions, with lower SpO2 (p = 0.010) and higher RPE (p = 0.008) when wearing the face mask only at the moderate intensity. In conclusion, the FFP2/N95 face mask impacted performance in the high-intensity resistance bench press exercise until movement failure but decreased oxygen saturation and increased rate of perceived effort only in the moderate-intensity exercise in recreational weight lifters. COVID-19 pandemic, has led to several countries adopting the use of masks in public spaces. Mask used during physical exercise it may induce early fatigue. However, despite the results with aerobic exercise, as far as we know, no studies have been carried out on wearing a mask during resistance exercise. This randomized, crossover study verified the acute effect of an FFP2/N95 face mask on moderate- and high-load upper body resistance exercise performance in recreational weight lifters. The FFP2/N95 face mask impacted performance, evaluated with bar velocity, in the high-intensity resistance bench press exercise until movement failure but decreased oxygen saturation and increased rate of perceived effort only in the moderate-intensity exercise.

Potential benefits of a ketogenic diet to improve response and recovery from physical exertion in people with Myalgic encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A feasibility study

Background: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) affects approximately 250,000 people in the UK. The condition varies in severity causing long-term physical and cognitive fatigue which is not alleviated by rest. Whilst the pathology is not understood, recent evidence suggests metabolic abnormalities may be associated with the manifestation of symptoms, particularly involving the metabolism of glucose and energy production. The use of ketone bodies as an alternative energy substrate may be beneficial to people with ME/CFS, in order to by-pass the glycolytic pathway, enhance energy production and reduce fatiguing outcomes. Study Design and Methods: Using a pragmatic collective case study with repeated measures methodology we investigated the feasibility of following a ketogenic diet and potential effects of the high fat, low carbohydrate diet on response to physical activity in people with ME/CFS (n=3) and healthy controls (n=3) using a submaximal exercise stress test both with and without dietary intervention. Exercise tolerance (mins), rate of oxygen consumption (VO2) to workload (75W), respiratory exchange ratio (RER), rate of perceived effort (RPE) and lactate response were measured throughout and descriptive statistics performed. Results: We found that the ketogenic diet was followed, with compliance higher in the pwME/CFS. Variations in response following the ketogenic diet was observed across individuals in minutes performed, VO2, HR, RER, and RPE post diet but the KD only limited exercise capacity in the control individuals. Individuals responded differently to the KD but group trends have been reported as means and standard deviation. The KD resulted in a decrease in RER at submax in the controls with a mean change of 0.07 from baseline (0.86 ± 0.1) to post intervention (0.79 ± 0.1) compared to a mean change of 0.02 in the ME/CFS from baseline (1.03 ± 0.1) to post intervention (1.01 ± 0.1). A decrease in VO2 (L/min) at submax showed a mean change of 0.06 (L/min) in the pwME/CFS at baseline (1.34 ± 0.1) to post intervention (1.27 ± 0.2) compared to a mean change of 0.07 (L/min) in the controls at baseline (1.40 ± 0.3) to post intervention (1.33 ± 0.2). HR (bpm) at submax decreased in all individuals, with a mean change of 4 (bpm), with pwME/CFS at baseline (139 ± 8.2) to post intervention (135 ± 14) and control individuals at baseline (107 ± 7.8) to intervention (103 ± 3.2). RPE at submax decreased in the pwME/CFS from baseline (6 ± 1.0) to post intervention (5 ± 2.1) whereas the controls increased from baseline (2 ± 1.0) to post intervention (3 ± 1.5). Conclusion: Our observations suggest individualised but metabolic flexibility in healthy individuals is achievable via dietary manipulation showing the ability to switch from glucose to fats under controlled conditions. The different response in substrate utilisation in individuals with ME/CFS suggests that potential metabolic abnormalities may be present in ME/CFS. Further investigation is now warranted in order to assess whether the KD is beneficial for people with ME/CFS

Treadmill and Running Speed Effects on Acceleration Impacts: Curved Non-Motorized Treadmill vs. Conventional Motorized Treadmill.

An increase in the popularity of running can be seen over the last decades, with a large number of injuries on it. Most of the running injuries are related to impact accelerations and are due to overuse. In order to reduce the risk of injury or to improve performance and health new treadmill designs have been created, as it can be the curved non-motorized treadmill. The aim of this study was to analyse impact accelerations, spatio-temporal parameters and perceptual differences while running on curved non-motorized treadmill (cNMT) compared to motorized treadmill (MT) at different speeds. Therefore, 27 recreational runners completed two tests consisting of 10 min warm-up and three bouts of 8 min running at 2.77 m/s, 3.33 m/s and self-selected speed on cNMT and MT, previously randomised. Although the surface did not influence spatio-temporal parameters, a reduction in impact accelerations, head acceleration rate (mean effect size [ES] = 0.86), tibia peak (mean ES = 0.45) and tibia magnitude (mean ES = 0.55), was observed while running on cNMT in comparison with running on MT. Moreover, higher heart rate (HR) (mean ES = 0.51) and rating of perceived effort (RPE) (mean ES = 0.34) were found while running on cNMT. These findings demonstrated that higher intensity training and lower impact accelerations are experimented on cNMT, what can be used by trainers and athletes while planning training sessions.

Moderators of Perceived Effort in Adolescent Rowers During a Graded Exercise Test.

Physical activity promotes mental health. A key factor is self-regulation. In the field of sports, self-regulation is related to the psychophysiological competence of rating of perceived effort (RPE). It was reported that adolescents have lower RPE competencies than adults, and it was hypothesized that this effect depends on physiological and cognitive development. The present study investigated in a sample of adolescents whether the RPE is related to basic cognitive competencies. Twelve rowers performed cognitive tests and a graded exercise test on a rowing ergometer, in which they continuously rated their perceived effort. Objective load measures and subjective perceptions were highly correlated (rho = 0.95–0.99). Furthermore, these correlations were inter-individually moderated by measures of mental speed and spontaneous flexibility. The results confirm the significance of basal cognitive competencies for conscious load perception. It is discussed whether regular sport has beneficial effects on the development of RPE competencies by enhancing cognitive regulation.

Does a standard school trolley fit children of different heights?

Although school trolleys are an alternative to traditional backpacks, no studies have determined their suitability for children of different heights. This study aims to analyse the fit of a school trolley (0.89 m height from the top to the bottom of the handle) for children with different heights based on kinematic variables and the rate of perceived effort (RPE). A 3D motion capture system was used to analyse the kinematics of the thorax and hip during walking without load and when pulling a trolley loaded with 15% of the child’s body weight (BW). The RPE was recorded at the end of each trial. The height of the subjects was clustered using Ward´s hierarchical cluster, and two groups were identified: Group 1: 120–139.9 cm; and Group 2: 140–160 cm. No differences were found between groups in the kinematics or RPE. In conclusion, a standard school trolley fits well to children with heights from 120 to 160 cm. Practitioner Summary: No studies have determined the suitability of school trolleys for children of different heights. This study aims to analyse the fit of a school trolley for children with different heights based on the kinematics and rate of perceived effort. The major finding is that a standard school trolley fits children with heights from 120 to 160 cm well and that the height of the school trolley was between 59% and 68% of the children’s heights. Abbreviations: RPE: rate of perceived exertion; BW: body weight; CAST: calibrated anatomical system technique; GC: gait cycle

Training load monitoring in football: application of field systems in professional male players (PhD Academy Award)

As a practitioner involved in player’s monitoring, one of my duties was to establish monitoring practices to inform the coaching and sports medicine departments about the training process. In this...

Behavioral changes to repeated takeovers in automated driving: The drivers’ ability to transfer knowledge and the effects of takeover request process

Only a couple of studies evaluated whether drivers of automated vehicles change their takeover behavior when they experience takeover requests repeatedly. Even less evidence was accumulated regarding the question whether drivers are able to transfer learned behavior to takeover situations with varying visibility characteristics and whether drivers’ takeover behavior depends on the takeover process in these situations. This paper therefore examines three research questions. First, it assesses how drivers change their behavior with the repeated experience of a takeover situation with the same visibility (fog or no fog). Second, it tests whether drivers can transfer their learned takeover behavior from a takeover situation with high or low visibility to the same takeover situation with different visibility conditions. Third, it assesses whether drivers’ takeover behavior and their experience of the situation differ between a one-step and a two-step takeover request process. Forty participants experienced a takeover situation three times. Experimental trials varied between-subjects concerning the permanent presence or absence of fog in the adaptation condition, the change of visibility conditions from fog to no fog or vice versa in the transfer condition, and the design of the takeover process with one-step or two-steps. Dependent variables included participants’ takeover time, minimum time-to-collision (TTCmin) with the construction site, deceleration and maximum steering behavior, and their ratings of criticality of the driving situation and perceived effort. Results show that participants adapted their deceleration behavior when repeatedly experiencing a takeover situation with the same visibility characteristics (adaptation condition). Changing these characteristics (transfer condition) lead to increased minimum TTCs, criticality and perceived effort ratings. In general, participants were able to maintain their takeover behavior in takeover situations with varying visibility characteristics indicating that they can transfer their takeover behavior across situations. Finally, the two-step takeover request process was associated with longer takeover times. However, minimum TTCs were larger and maximum steering movements and criticality ratings were lower compared to the one-step process. We conclude that drivers transfer their behavior across takeover situations. However, this performance comes at higher costs in terms of perceived effort and criticality. In addition, two-step takeover request processes should be favored over one-step processes when designing takeover requests. Future studies should examine the validity of the results in various takeover situations and on-the-road studies.

Effect Of Caffeine Ingestion On Performance During A Repeated-bout Agility Test In Handball Players

PURPOSE: To verify whether caffeine would alter the psychophysiological responses and agility performance during repeated bouts of an agility test in handball players. METHODS: 10 recreationally handball players (20.6 ± 3.3 years, 81.5 ± 10.0 kg, 1.80 ± 0.1 m) performed 6 exercise bouts, interspersed by 1-min recovery intervals, of an agility test (Illinois Agility Run Test) 60 min after ingesting, in a double-blind matter, either caffeine (5 mg·kg-1 of body mass) or placebo (cellulose). The total exercise-bout time (sum of all time during each of the 6 exercise bouts) was compared between conditions using a paired t test, while the rating of perceived effort (RPE), heart rate (HR) and blood lactate concentration ([La]) were compared between conditions using a two-way repeated-measures ANOVA (condition and bout factors). RESULTS: There was no significant difference between caffeine (114.3 ± 5.9 s) and placebo (114.4 ± 4.7 s) conditions for total exercise-bout time (P > 0.05). The RPE increased progressively throughout the test in all conditions (P < 0.05), but without significant differences between caffeine (bout 1: 8.1 ± 1.6; bout 6: 15.6 ± 4.1) and placebo (bout 1: 7.9 ± 1.1; bout 6: 15.5 ± 4.0) conditions (P > 0.05). Similar responses were found for HR, revealing an exponential increase during the test in both conditions (P < 0.05), but with no differences when caffeine condition (rest: 74 ± 17 bpm; bout 6: 179 ± 14 bpm) was compared with placebo condition (bout 1: 83 ± 15 bpm; bout 6: 183 ± 14 bpm; P > 0.05). Furthermore, the [La] increased linearly over the test in both conditions (P < 0.05), but it was significantly higher in caffeine (16.2 ± 2.7 mmol·L-1) compared with placebo (13.8 ± 2.9 mmol·L-1) 3 min after the repeated-bout agility test (P < 0.05). CONCLUSION: Caffeine ingestion increases the glycolytic flux but does not alter the performance during a repeated-bout agility test in handball players.