Convergent Validity of Ratings of Perceived Exertion During Resistance Exercise in Healthy Participants: A Systematic Review and Meta-Analysis

Background The validity of ratings of perceived exertion (RPE) during aerobic training is well established; however, its validity during resistance exercise is less clear. This meta-analysis used the known relationships between RPE and exercise intensity (EI), heart rate (HR), blood lactate (BLa), blood pressure (BP) and electromyography (EMG) to determine the convergent validity of RPE as a measure of resistance exercise intensity and physiological exertion, during different forms of resistance exercise. Additionally, this study aims to assess the effect of several moderator variables on the strength of the validity coefficients, so that clearer guidance can be given on the use of RPE during resistance exercise. Methods An online search of 4 databases and websites (PubMed, Web of Science SPORTDiscus and ResearchGate) was conducted up to 28 February 2020. Additionally, the reference lists of the included articles were inspected manually for further unidentified studies. The inclusion criteria were healthy participants of any age, a rating scale used to measure RPE, resistance exercise of any type, one cohort receiving no other intervention, and must present data from one of the following outcome measures: EI, HR, BP, EMG or BLa. Weighted mean effect sizes (r) were calculated using a random-effects model. Heterogeneity was assessed using the τ2 and I2 statistics. Moderator analysis was conducted using random-effects meta-regression. Results One-hundred and eighteen studies were included in the qualitative synthesis, with 75 studies (99 unique cohorts) included in the meta-analysis. The overall weighted mean validity coefficient was large (0.88; 95% CI 0.84–0.91) and between studies heterogeneity was very large (τ2 = 0.526, I2 = 96.1%). Studies using greater workload ranges, isometric muscle actions, and those that manipulated workload or repetition time, showed the highest validity coefficients. Conversely, sex, age, training status, RPE scale used, and outcome measure no significant effect. Conclusions RPE provides a valid measure of exercise intensity and physiological exertion during resistance exercise, with effect sizes comparable to or greater than those shown during aerobic exercise. Therefore, RPE may provide an easily accessible means of prescribing and monitoring resistance exercise training. Trial Registration The systematic review protocol was registered on the PROSPERO database (CRD42018102640).

The Effects of Heart Rate Monitoring on Ratings of Perceived Exertion and Attention Allocation in Individuals of Varying Fitness Levels

There has been a rapid increase in the use of wearable technology-based physical activity trackers. Most of these physical activity trackers include tracking and displaying the individual's heart rate (HR). There is little known about how HR monitoring influences the perception of exertion and attention allocation. Shifting attentional focus toward the body (association), such as monitoring HR, instead of environmental stimuli (dissociation) may increase one's perceived level of exertion. The purpose of the study was to examine the effects of HR monitoring on ratings of perceived exertion (RPE) and attention allocation during an exertive stepping task in individuals of varying fitness levels. The YMCA stepping task normative values determined fitness levels. For the experimental condition, participants were randomly assigned to one of two conditions (i.e., HR monitoring or control) and completed a stepping task with a weighted vest at 20% of their bodyweight. HR, RPE, and attention allocation were collected at 30-s intervals. Performing the stepping task resulted in a gradual increase of HR and RPE along with a shift from dissociative to associative attention across all conditions. Monitoring one's HR during the task resulted in more dissociative attention allocation, however, no RPE differences were reported between the two conditions. Unfit individuals reported lower levels of RPE during the first time point compared to fit individuals despite having higher HR throughout the task. The results of this study have relevance for applied practitioners implementing physical activity interventions with individuals who monitor their HR.

A Cloth Facemask Causes No Major Respiratory or Cardiovascular Perturbations during Moderate to Heavy Exercise

Objectives: To investigate whether wearing a cloth facemask could affect physiological and perceptual responses to exercise at distinct exercise intensities in non-trained men and women. Methods: In a crossover design, participants (17 men and 18 women) underwent a progressive square-wave test at four intensities (i. at 80% of the ventilatory anerobic threshold [80%VAT]; ii. at VAT; iii. at the respiratory compensation point [RCP]; iv. at exercise peak [Peak] to exhaustion), with or without a triple-layered cloth mask (Mask or No-Mask). Several physiological, metabolic and perceptual measures were analyzed. Results: Mask reduced inspiratory capacity at all exercise intensities vs. No-Mask (p<0.0001), irrespective of sex. Mask reduced respiratory frequency vs. No-Mask (p=0.001) at Peak (-8.3 breaths/min; CI: -5.8, -10.8), RCP (-6.9 breaths/min; CI: -4.6, -9.2) and VAT (-6.5 breaths/min; CI: -4.1, -8.8), but not at Baseline or at 80%VAT. Mask also reduced tidal volume (p<0.0001) at both RCP (-0.5L; CI: -0.3, -0.6) and Peak (-0.8L; CI: -0.6, -0.9), but not at Baseline, 80%VAT or VAT. Shallow breathing index was increased with Mask at Peak compared to No-Mask (11.3; CI: 7.5, 15.1), but not at any other intensities. Mask did not change heart rate, lactate, ratings of perceived exertion, blood pressure or oxygen saturation. Conclusions: Wearing a cloth facemask during exercise at moderate to heavy intensities is unlikely to incur significant respiratory or cardiovascular changes, irrespective of sex. These data can inform new exercise recommendations for health during the COVID-19 pandemic and debunk unfounded allegations of harmful effects of masks during exercise. ClinicalTrials.gov: NCT04887714

Palatable Flavoured Fluids without Carbohydrates and Electrolytes Do Not Enhance Voluntary Fluid Consumption in Male Collegiate Basketball Players in the Heat

Using palatable fluids to enhance drinking in athletes who display insufficient compensatory hydration behaviour may mitigate the risks of hypohydration and performance deficits. However, it is unclear whether flavour can independently enhance fluid consumption. This study examined the effects of a colourless, artificially sweetened flavoured water (FW), without carbohydrates and with negligible amounts of sodium, compared to plain water (W) on fluid consumption in male collegiate basketball players in a practical game setting. Eighteen male basketball players (age 23.1 ± 1.3 years) played a 3v3 basketball small-sided game. The players were randomly assigned to consume either FW or W. Pre-game urine-specific gravity, fluid consumption, body mass, and hedonic taste perceptions were assessed. Basketball performance was analysed through notational analysis. Ratings of perceived exertion and thirst were recorded at pre-, post-game, and at each rest period. Heart rate was recorded throughout the gameplay. Despite significantly higher hedonic ratings for FW than W (6.78 ± 0.83 vs. 5.56 ± 1.33, p = 0.033, d = 1.36), there were no significant differences in fluid consumption (1083 ± 32 mL vs. 1421 ± 403 mL, p = 0.068, d = 0.92). Our result highlighted that using palatable fluids as a strategy to increase fluid consumption during high-intensity gameplay in the heat may not be effective if used without carbohydrates and electrolytes. Practitioners could consider both fluid palatability and composition in establishing a hydration plan for athletes.

Recovery behavior after matches for returning to training in volleyball athletes

The aim of this research was to evaluate the behavior of vertical jumps performance in professional volleyball athletes during matches and training and their relationships with fatigue and recovery through heart rate variability (HRV), ratings of perceived exertion (RPE) and perceived recovery status (PRS). Nine male professional volleyball athletes participated in the study, with mean age: 25.66 ± 5.7 years, mean body mass: 97.81 ± 8.65 Kg and mean height: 200.94 ± 5.19 cm, with experience in national and international competitions. HRV and PRS were evaluated in the morning of matches and in the presentation for the first day of training after matches. RPE was collected immediately after matches and at the end of training days. Jumps performance was monitored during the matches and during the first days of training. The data was grouped by matches and training sessions. Significance level adopted was α ≤ 0.05. There were no alterations in HRV and PRS evaluated after matches and before training sessions, as well as in RPE after training. Jumps height was greater during the matches (p< 0.013) and there were no differences in the number of jumps. There was a positive correlation between the number of jumps during matches and PRS before matches (r= 0.336, p= 0.015) and a negative correlation between the number of jumps during training and pre-training PRS (r= -0.318, p= 0.002). We conclude that the recovery period proposed by the team proved to be sufficient for the athletes to maintain the same condition for returning to training. This information can assist physical trainers to prescribe training loads for the return to training.

Sex-Specific Physical Performance Adaptive Responses Are Elicited After 10 Weeks of Load Carriage Conditioning

ABSTRACT Introduction The purpose of this study was to identify and characterize sex-specific physical and psychophysical performance adaptations in response to a novel 10-week training program. Materials and Methods Fifteen males and thirteen females completed a standardized load carriage task (5 km at 5.5 km.h−1, wearing a 23 kg torso-borne vest) before and after 10 weeks of resistance and load carriage training. Psychophysical responses (i.e., heart rate and ratings of perceived exertion) were measured throughout the load carriage task. Physical performance (i.e., countermovement and squat jumps, push-ups, sit-ups, and beep test) was measured at before, mid-way, and after the training program (weeks 0, 6, and 11, respectively). Results Training elicited significant improvements in squat jump maximal force, push-ups, and beep test performance (P &lt; .05). Males outperformed females in all performance measures, with interactions (time, sex) for push-ups, sit-ups, and beep test performance. After training, aerobic capacity improved by 5.4% (42.9 mL· kg−1· min−1 to 45.2 mL· kg−1· min−1) in males but did not improve in females. Psychophysical responses decreased for both sexes (P &lt; .05) during the load carriage task post-training. Conclusion While 10 weeks of standardized training elicited positive adaptations in both physical and psychophysical performance, sex-specific differences were still evident. To lessen these differences, sex-specific training should be considered to optimize load carriage performance.

Effects of Different Seat Pressures and Rowing Cadences on Muscle Oxygenation and Physiological Parameter Responses

This study investigated the effects of rowing with different seat cushion and cadence conditions on oxyhemoglobin (O2Hb) and total hemoglobin (tHb) levels of the erector spinae (ES) as well as the effects on heart rate (HR) and ratings of perceived exertion (RPE). Thirty healthy adults completed tests under three unstable air seat cushion pressure levels (0, 80, and 140 mmHg) and three rowing cadences (slow: 18 bpm, medium: 30 bpm, and fast: 36 bpm) on a rowing machine, for a total of nine test conditions. During the exercise period, rowing on cushions set to 80 mmHg resulted in greater O2Hb and tHb changes than did rowing at 0 mmHg (p < 0.05). When rowing cadence increased, the O2Hb and tHb decreased during the exercise period, whereas HR and RPE increased (p < 0.05). During the recovery period, O2Hb and tHb on cushions set to 140 mmHg during slow rowing were higher than those at 0 mmHg during slow rowing and 140 mmHg during fast rowing (p < 0.05). Rowing on an appropriate pressure of seat cushion and using a slow cadence contribute to increasing muscle oxygenation of low back during exercise.