Changes In Ratings Of Perceived Exertion Research Articles

Affect and exertion during incremental physical exercise: Examining changes using automated facial action analysis and experiential self-report.

Recent research indicates that affective responses during exercise are an important determinant of future exercise and physical activity. Thus far these responses have been measured with standardized self-report scales, but this study used biometric software for automated facial action analysis to analyze the changes that occur during physical exercise. A sample of 132 young, healthy individuals performed an incremental test on a cycle ergometer. During that test the participants' faces were video-recorded and the changes were algorithmically analyzed at frame rate (30 fps). Perceived exertion and affective valence were measured every two minutes with established psychometric scales. Taking into account anticipated inter-individual variability, multilevel regression analysis was used to model how affective valence and ratings of perceived exertion (RPE) covaried with movement in 20 facial action areas. We found the expected quadratic decline in self-reported affective valence (more negative) as exercise intensity increased. Repeated measures correlation showed that the facial action mouth open was linked to changes in (highly intercorrelated) affective valence and RPE. Multilevel trend analyses were calculated to investigate whether facial actions were typically linked to either affective valence or RPE. These analyses showed that mouth open and jaw drop predicted RPE, whereas (additional) nose wrinkle was indicative for the decline in affective valence. Our results contribute to the view that negative affect, escalating with increasing exercise intensity, may be the body's essential warning signal that physiological overload is imminent. We conclude that automated facial action analysis provides new options for researchers investigating feelings during exercise. In addition, our findings offer physical educators and coaches a new way of monitoring the affective state of exercisers, without interrupting and asking them.

Analyzing the effects of combined small-sided games and strength and power training on the fitness status of under-19 elite football players.

The purpose of this study was twofold: 1) to characterize a common microcycle considering both internal and external training loads; and 2) to identify the effects of small-sided games (SSGs) and of power and strength training on the fitness status of football players. Fifteen male football players (age: 18.55±0.39 years) participated in this study. Ninety-two consecutive training sessions were monitored and analyzed over a period of nineteen weeks. Rating of perceived exertion (RPE ) was used as an internal load marker, and the distances covered at different speed thresholds and accelerations/decelerations were used as external load markers to characterize the common microcycle. Participants' body composition, vertical jumping ability, maximal strength, speed, and agility were assessed twice before and after the training monitoring process. The results revealed that match day -5 (MD-5) and MD-1 were associated with the lowest RPE scores (4.2 and 3.8 A.U., respectively). MD-4 and MD-3 were associated with the highest RPE values (9.2 and 8.8 A.U., respectively). Meaningful changes in RPE were found between training days. External load monitoring revealed that MD-4 had the highest values of accelerations and decelerations >2 m/s2/min (4.22 and 3.17, respectively) and MD-3 had the highest values of distance covered at high intensity (6.11 m/s2/min). Meaningful moderate improvements in jumping performance (d=0.90) and maximal strength parameters (d=0.83) were also found between assessments. It was identified that the concurrent approach had meaningful impacts on the fitness development of players and should be considered by coaches for future training interventions.

Similar perceptual responses to reduced exertion high intensity interval training (REHIT) in adults differing in cardiorespiratory fitness

Reduced exertion high intensity interval training (REHIT) is an extremely low-volume approach of sprint interval exercise (SIE) that increases maximal oxygen uptake (VO2max) and reduces body fat. However, there are concerns regarding implementation of SIE including REHIT in untrained populations due to generation of supramaximal power outputs and potential feelings of displeasure. This study examined perceptual responses to a single REHIT session in adults with above (n = 43, VO2max = 41 ± 6 mL/kg/min) and below average VO2max (n = 42, VO2max = 33 ± 5 mL/kg/min). Initially, incremental exercise was completed to determine VO2max. Subsequently, participants completed REHIT consisting of two 20 s “all-out” sprints at resistance equal to 5 % body mass. Rating of perceived exertion (RPE), affective valence, and physical activity enjoyment (PACES) were determined. Tolerance and preference to exercise intensity were also measured to examine if they moderated the responses. Compared to participants with below average VO2max, those with above average VO2max revealed similar change in affective valence (p = 0.86), RPE (p = 0.41), and enjoyment (p = 0.64) despite attaining significantly higher peak and mean power output in response to REHIT. The lowest value of affective valence ranged from 1.0–1.5, representing “fairly good.” Overall, one session of REHIT elicits positive affective valence and similar pleasure:displeasure and enjoyment responses in individuals having diverse cardiorespiratory fitness, although we recommend that REHIT should be individualized for each client as greater frequency of aversive responses was shown in our participants with low fitness.

Perceptual changes to progressive resistance training with and without blood flow restriction

ABSTRACTThe purpose was to examine changes in the perceptual responses to lifting a very low load (15% one repetition maximum (1RM)) with and without (15/0) different pressures [40% (15/40) and 80% (15/80) arterial occlusion pressure] and compare that to traditional high load (70/0) resistance exercise. Ratings of perceived exertion (RPE) and discomfort were measured following each set of exercise. In addition, resting arterial occlusion pressure was measured prior to exercise. Assessments were made in training sessions 1, 9, and 16 for the upper and lower body. Data are presented as means and 95% CI. There were changes in RPE in the upper body with condition 15/40 [−2.1 (−3.4, −0.850)] and 15/80 [−2.4 (−3.6, −1.1)] decreasing by the end of training. In the lower body, RPE decreased in condition 15/40 [−1.4 (−2.3, −0.431)] by the end of the training study. There was a main effect of time in the upper body with all conditions decreasing discomfort. In the lower body, all conditions decreased except for 15/80. For arterial occlusion pressure, there were differences across time in the 15/40 condition and the 15/80 condition in the upper body. Repeated exposure to blood flow restriction may dampen the perceptual responses over time.

Effects of Different Fatigue Levels on Physiological Responses and Pacing in Judo Matches.

Franchini, E, Takito, MY, Alves, ED, Shiroma, SA, Julio, UF, and Humberstone, C. Effects of different fatigue levels on physiological responses and pacing in judo matches. J Strength Cond Res 33(3): 783-792, 2019-The objective of this study was to compare athletes' pacing during judo match simulation between different fatigue states. Twelve judo athletes (30.2 ± 3.2 years old, 85.6 ± 10.8 kg, 181.0 ± 5.7 cm, 19 ± 7 years of judo experience) completed three 4-minute matches against the same opponents, at 15-minute intervals in 3 different conditions: after warm-up (Control; C); after a regular training session (totaling 90 minutes); after a high-intensity interval exercise (2 blocks of 10 sets of 20-second all-out uchi-komi, with 10-second interval between sets and 5-minute interval between blocks). All matches were mediated according to the official rules, filmed, and analyzed concerning: rating of perceived recovery (RPR), rating of perceived exertion (RPE), heart rate (before and after match), blood lactate concentrations [La] before, peak after match and delta (peak minus the prematch values), and time-motion measures (frequencies and durations of actions). Time-motion measures included athlete displacement without contact, gripping, attack, feint, groundwork combat, pauses, and high- to low-intensity effort ratio. The experimental conditions resulted in different physiological and perceived responses prematch (HR, [La], RPR) and postmatch simulations (HR and [La]peak), with no change in RPE and few changes in technical variables. There was a decrease in grip dispute time, and increase in time of displacement without contact. These technical changes were enough to preserve the pace during the matches, which seemed to be controlled by the athletes to maintain their number of attacks, feints, and RPE.

Is Postexercise Blood Flow Restriction a Viable Alternative to Other Resistance Exercise Protocols?

ABSTRACTPurpose: The purpose of this study was to identify whether post-resistance exercise (REx) blood flow restriction (BFR) can elicit a similar acute training stimulus to that offered by either heavy REx or traditional low-load BFR REx. Method: Ten men completed trials with 30% one-repetition maximum (1RM) for 5 sets of 15 repetitions without BFR (30%), with BFR during exercise (30% RD), and with postexercise BFR (30% RP) and at 75% 1RM for 3 sets of 10 repetitions. Lactate and cortisol were measured before and up to 60 min after exercise. Thigh circumference, ratings of perceived exertion (RPE), and pain were measured before and after exercise. Surface electromyography was measured during exercise. Results: All conditions had a large effect (effect size [ES] > 0.8) on lactate, with the largest effects observed with the 75% condition; no differences were observed between the 30% conditions. All conditions had a moderate effect (ES > 0.25 ≤ 0.4) on increasing thigh circumference. This effect was maintained (ES = 0.35) with the application of BFR after REx (30% RP). Change in RPE, from the first to last set, was significantly greater with 30% RD compared with other conditions (all p < .05). Electromyography amplitude was higher and percentage change was greater for the 75% condition compared with the other conditions (both p < .05). Conclusions: The application of BFR immediately post-REx altered several of the responses associated with REx that is aimed at inducing muscular hypertrophy. Additionally, these changes occurred with less pain and perceived exertion suggesting that this form of REx may offer an alternative, tolerable method of REx.

Monitoring Resistance Exercise Intensity Using Ratings of Perceived Exertion in Previously Untrained Patients With Prostate Cancer Undergoing Androgen Deprivation Therapy.

Fairman, CM, LaFountain, RL, Lucas, AR, and Focht, BC. Monitoring resistance exercise intensity using ratings of perceived exertion (RPE) in previously untrained patients with prostate cancer undergoing androgen deprivation therapy. J Strength Cond Res 32(5): 1360-1365, 2018-Exercise has been shown to be safe and effective for patients with prostate cancer (PrCa). The monitoring of resistance exercise (RE) intensity is an emerging area of interest in RE prescription. Rating of perceived exertion (RPE) is one of the most commonly used methods but has not yet been validated in this population. Thus, the purpose of this study was to examine the relationship between RPE and RE intensity in PrCa. Data for this study were abstracted from baseline upper- and lower-body strength assessments from 2 previous trials (Individual Diet and Exercise Adherence Pilot Trial; Livestrong, Austin, TX, USA) in our laboratory investigating functional outcomes in patients with PrCa undergoing androgen deprivation therapy (ADT). A total of 75 participants from both trials were included in this study. Ratings of perceived exertion corresponding to 50, 70, and 90% 1 repetition maximum (1RM) were extracted from the results of participants' upper- and lower-body 1RM strength tests. The changes in RPE across increasing intensities were assessed using separate univariate analysis of variance (ANOVA). For each ANOVA, RPE was used as the dependent variable and intensity (50, 70, and 90%) used as the fixed factor. A univariate ANOVA revealed a significant difference (p ≤ 0.05) among the RPE values for each intensity for both upper- and lower-body lifts. The results of our analyses suggest that RPE values rise linearly in response to increases in exercise intensity. Our study supports the concept that RPE may be a practical training tool to accurately estimate RE intensity in PrCa survivors undergoing ADT. Practitioners may consider using RPE to monitor and adjust RE intensity in this population.

Effects of Recovery Nutrition on Body Composition and Session RPE in Collegiate Tennis Players

Athletes often overlook the psychological and physiological importance of recovery nutrition in athletic performance. Little research has investigated the role of recovery nutrition on perceived exertion in college athletes. PURPOSE: To examine the perceived and physiological effects of regular, whole food, recovery nutrition on session rating of perceived exertion (RPE) and body composition in collegiate athletes. METHODS: Female tennis players (n=8, age 20.1±1.4 years; weight 66.8±6.9 kg) volunteered for the 8-week study during their competitive season. Air displacement plethysmography was used to estimate fat mass (FM) and fat-free mass (FFM) at baseline, 4-week, and end of the 8-week intervention. Seven training sessions (60 min), consisting of high intensity strength and power exercises, were performed during each 4-week phase of the study. Athletes continued their normal pattern during the first 4-weeks (T1) and were provided with standardized recovery nutrition at the conclusion of each training session for the second 4-weeks (T2). RPE on a scale of 0-10 was reported immediately after each training session. Recovery nutrition consisted of a 3” red apple, 7” banana, 1.05 oz. peanut butter spread, and an 85g bagel or 99g gluten-free bagel. Nutritional composition for a standard snack bag was 680kcal, 106g carbohydrate, 17.8g protein, 24.7g fat, while a gluten-free snack bag totaled 740kcal, 107g carbohydrate, 18.8g protein, 31.7g fat. Participants were instructed to consume all foods within an hour of the training session. Repeated measures ANOVA was used to examine changes in session RPE and body composition over time. RESULTS: There was a main effect of recovery nutrition on session RPE (p<0.001) with a lower RPE reported in T2 (3.53±1.24) than T1 (4.50±1.44). FM and FFM decreased 0.05kg and 0.28kg, respectively; however, changes were not significant (p>0.05). Athletes reported an increased quality of training with recovery nutrition. Conclusions: Four weeks of recovery nutrition resulted in a ~10% decrease in session RPE in female tennis players. Further, athletes perceived they trained harder during the sessions with recovery nutrition. Future research would be beneficial to determine the direct effects of recovery nutrition on performance. Supported by EWU’s Start Something Big Grant - 7F16.

Histamine‐Receptor Antagonists Affect Endurance Exercise Performance in Highly Competitive Cyclists

Histamine‐receptor antagonists (“antihistamines”) are widely used among endurance athletes and are not currently banned by the World Anti‐Doping Agency. Our lab has recently shown that a single dose of antihistamines prior to muscle‐damaging exercise attenuates strength loss and muscle pain in the 72 hours following exercise. Histamine, produced within muscle, may be a factor in exercise‐induced muscle pain/discomfort and, therefore, perception of effort, as group III/IV muscle afferents (nociceptive neurons) are sensitized via activation of H1 and H2 receptors. Histamine may have more influence on muscle pain and effort sensations during long‐duration exercise than short‐duration, because the activity of histidine decarboxylase (the enzyme that creates histamine) increases with exercise duration. Therefore, the purpose of this experiment was to determine if combination H1/H2 antihistamines increase endurance exercise performance. It was hypothesized that H1/H2 antihistamines would decrease the time to completion of a fixed‐distance time‐trial compared to placebo, and the effect would be greater following an endurance‐exercise bout. Eleven (3F) highly competitive cyclists (Cat 1–3) performed six 10 km time‐trials on separate days. The first two trials served as a familiarization, and repeatability was assessed by calculating a coefficient of variation (CV) between times to completion. The next 4 trials were performed in a randomized‐block order. Two were preceded by 120 min of seated rest and two by 120 min of steady‐state cycling at 50% VO2peak. Within those blocks, volunteers consumed either antihistamines (540 mg fexofenadine; a H1 receptor blocker, and 300 mg of ranitidine; a H2 blocker) or placebo 60 min prior to the start of rest/exercise. The main outcome variable was 10 km time to completion. Additionally, rating of perceived exertion (RPE), isometric quadriceps muscle strength, blood glucose, and blood lactate were measured prior to and following the time‐trials. Conventional statistics (2‐Way Repeated Measures ANOVA), effect size (ES = Cohen's dz), 95% CI, and CV from familiarization trials were used to determine the presence, strength, and meaningfulness of differences, respectively, between the trials. There was a significant reduction in performance with antihistamines compared to placebo (+10.5 ± 3.8 s, mean±SEM, drug effect p=0.002), the reduced performance tended to be exacerbated by prior exercise (p=0.057) but there was no drug by prior exercise interaction (p=0.716) (Figure 1). The day‐to‐day 10 km performance variability (CV) was 0.98%. The percent change between placebo and antihistamine was likely trivial for time‐trials following rest (mean −0.87%, 95%CI −2.02 to 0.29%) (ES=0.505) and potentially harmful following exercise (mean −1.2%, 95%CI −2.45 to 0.05%) (ES=0.646). There were no drug effects on changes (pre to post time‐trial) in isometric muscle strength (p=0.607), RPE (p=0.828), blood glucose (p=0.964) or lactate (p=0.402) between antihistamine and placebo conditions. Thus, contrary to our hypothesis, blocking histamine's receptors slowed performance of 10 km time‐trials in highly competitive cyclists and did not influence perception of effort.Support or Funding InformationEugene &amp; Clarissa Evonuk Memorial Graduate FellowshipThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The Effect of a Backpack Hip Strap on Energy Expenditure While Walking.

Objective To examine the effect of backpack hip strap use on walking energy expenditure while carrying a loaded backpack. Background Previous studies have demonstrated that energy cost increases as the mass of the load carried increases. However, few investigations have focused on backpack carriage design. Methods Fifteen young, healthy, male subjects walked at a self-selected pace for 10 minutes in two backpack loading conditions: with a hip strap (strapped) and without a hip strap (nonstrapped). Oxygen consumption (VO2), rating of perceived exertion (RPE), respiratory exchange ratio (RER), and heart rate (HR) were monitored throughout each 10-minute trial. Change scores from the 4th to 10th minute were calculated for each variable. A t test was used to evaluate the difference between conditions for each variable. Results The changes in VO2 (-0.62 ± 0.40 vs. 0.33 ± 0.23, p = .04) and RPE (1 ± 0.25 vs. 2 ± 0.21, p < .01) from the 4th to the 10th minute were different for the strapped versus nonstrapped condition. There was no difference in the change in RER (0.04 ± 0.01 vs. 0.03 ± 0.01, p > .05) or HR (3.53 ± 0.93 vs. 4.07 ± 1.39, p > .05) for the strapped versus unstrapped condition. Conclusions Wearing a hip strap reduced the energy expenditure and perceived exertion in as little as 10 minutes of walking compared to the nonstrapped condition. Future work should consider the effect of a hip strap on these variables while hiking for extended periods. Application Wearing a hip strap may increase the comfort and reduce the energy required of wearing a backpack. This is useful information for backpack designers, military personnel, and recreational hikers.

The Effect of a Backpack Hip Strap on Energy Expenditure While Walking.

Previous studies have demonstrated that the energy cost of carrying a backpack increases as the mass of the load carried increases. Conflicting results have been found when research examined the effect of duration on energy expenditure while carrying a backpack. A potential confounding variable could be the design of the backpack, particularly the use of a backpack hip strap. PURPOSE: To examine the effect of backpack hip strap use on walking energy expenditure while carrying a loaded backpack. METHODS: A crossover design was used in which fifteen young, healthy male subjects walked at a self-selected pace for two 10-minutes in two backpack loading conditions: with a hip strap (strapped) and without a hip strap (non-strapped). Oxygen consumption (VO2), rating of perceived exertion (RPE), respiratory exchange ratio (RER), and heart rate (HR) were monitored throughout each 10-minute trial. Change scores from the 4th to 10th minute were calculated for each variable. A t-test was used to evaluate the difference between conditions for each variable. RESULTS: The change in VO2 (-0.62 ± 0.40 vs. 0.33 ± 0.23, p = 0.04) and change in RPE (1 ± 0.25 vs. 2 ± 0.21, p &lt 0.01) from the 4th to the 10th minute were different for the strapped versus non-strapped condition, respectfully. There was no difference in the change in RER (0.04 ± 0.01 vs. 0.03 ± 0.01, p &gt 0.05) or HR (3.53 ± 0.93 vs. 4.07 ± 1.39, p &gt 0.05) for the strapped versus unstrapped condition, respectfully. CONCLUSIONS: Wearing a hip strap reduced the energy expenditure and perceived exertion in as little as 10 minutes of walking compared the non-strapped condition. Future work should consider the effect of a hip strap on these variables while hiking for extended periods.

Acute effect of uphill and downhill treadmill walk on cardiovascular response and perceived exertion in young sedentary individual

Background: Systematic exercise is an essential component for health promotion and improvement of the quality of life. Exercise that emphasizes on the eccentric (lengthening) skeletal muscle contractions has recently gained attention due to its benefits over conventional exercise that predominantly involves concentric (shortening) muscle contractions. The mechanical efficiency of walking on an inclined (uphill) and a declined (downhill) treadmill is equivalent to those of concentric and eccentric muscle contraction, respectively. Objective: To compare the acute effect of uphill (concentric exercise) and downhill (eccentric exercise) treadmill walk on physical exertion and cardiovascular response. Materials and Methods: The present crossover study involved 30 males, aged 20.6 ± 1.9 years, having a body mass index of 20.7 ± 1.4 kg/m2. Participants did an acute bout of uphill (+0.16 grade) and downhill (−0.16 grade) treadmill walk at an average speed of 4.6 ± 0.4 km/h for 30 min. Borg’s 6-20 scale rating of perceived exertion (RPE), systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), mean arterial pressure (MAP), pulse pressure (PP), and rate pressure product (RPP) were the study parameters. Statistical analysis was done using paired t-test or Wilcoxon test. Results: The downhill walk caused a significant (P < 0.05) lower mean change in SBP, HR, MAP, PP, RPP, and RPE (26.7 ± 5.6, 58.2 ± 6.8, 16.2 ± 6.1, 15.9 ± 4.1, 106.3 ± 14.5, 12.5, respectively) as compared to uphill walk (22.3 ± 6.0, 40.3 ± 9.2, 12.53 ± 6.7, 14.0 ± 3.6, 74.6 ± 15.7, 11, respectively). The mean change in DBP was non-significant. Conclusion: Moderate-intensity downhill walk at −16% grade might be preferred for exercising individuals with a low tolerance to physical and cardiovascular stress.

Cancer Survivors Report Positive Affect during High-Intensity Group Based Exercise

PURPOSE: In rehabilitating populations, concerns arise with sustaining and adhering to popular group exercise programs of increased intensity due to the physically demanding requirements. Positive affect values like pleasure improve the likelihood of engaging in exercise behaviors. High-intensity functional training (HIFT) is a group-based exercise method of combined aerobic and resistance training functional exercises completed at relative high intensities. This study investigated effects of a HIFT program on cancer survivors’ perceptions of pleasure to predict efficacy and adherence. METHODS: Eight cancer survivors (53.5±5.0y, 75% female) participated in a 5-week, 3 days/week HIFT intervention, consisting of 12 workouts (WODS). For three pre-selected WODs, participants self-reported changes in mood/pleasure via the Feeling Scale (FS) from -5 (very bad) to +5 (very good); arousal via the Felt Arousal Scale (FAS) from 1 (very lowly) through 6 (very highly) aroused; and Rating of Perceived Exertion (RPE) via the Borg scale from 6 (resting) to 20 (maximal) at 6 times (after the warm-up, after ¼, ½, and ¾ of the WOD, immediately after the WOD, and after cool-down). Heart rate (HR) was assessed with Polar Pro-trainers throughout. Repeated measures ANOVA was used to examine within-measurement differences over time. Correlation analysis was used to compare RPE and HR for 2 exercise sessions. RESULTS: Average FS ratings ranged 1.3 to 3.4 indicating that mood remained positive throughout the session. Average RPE peaked immediately after the WOD and ranged from 6.9 to 15.5. Average predicted HRmax% for age was 80.2+/- 0.9 % throughout the WOD. There was main effect for changes in FAS over time, F(2,1)=16.0, p<.001, where the first measurement was significantly lower than all following measurements. There were significant main effects for changes in RPE, F(2,1)=43.2, p<.001, and HR, F(5,1)=74.8, p<.001, over time. Both were positively correlated, r=.97, p=.001 and had significantly greater values during the WOD than warm-up or cool-down. CONCLUSIONS: Improved FS during HIFT contrasts with previous research showing that pleasure decreases as physiological work demands reach high intensity. These data show that cancer survivors can sustain and even find high intensity exercise enjoyable.

Does one night of partial sleep deprivation affect the evening performance during intermittent exercise in Taekwondo players?

Athletes and coaches believe that adequate sleep is essential for peak performance. There is ample scientific evidence which support the conclusion that sleep loss seems to stress many physiological functions in humans. The aim of this study was to determine the effect of one night’s sleep deprivation on intermittent exercise performance in the evening of the following day. Ten male Taekwondo players performed the Yo-Yo intermittent recovery test (YYIRT) in three sleep conditions (reference sleep night [RN], partial sleep deprivation at the beginning of night [PSDBN], partial sleep deprivation at the end of night [PSDEN]) in a counterbalanced order, allowing a recovery period ≥36 hr in between them. Heart rate peak (HRpeak), plasma lactate concentrations (Lac) and rating of perceived exertion (RPE) were measured during the test. A significant effect of sleep restriction was observed on the total distance covered in YYIRT (P<0.0005) and Lac (P<0.01) in comparison with the RN. In addition, performance more decreased after PSDEN (P<0.0005) than PSDBN (P<0.05). Also, Lac decreased significantly only after PS-DEN (P<0.05) compared with RN. However, there were no significant changes in HRpeak and RPE after the two types of partial sleep deprivation compared to RN. The present study indicates that short-term sleep restriction affect the intermittent performance, as well as the Lac levels of the Taekwondo players in the evening of the following day, without alteration of HRpeak and RPE.

Increased physiologic intensity during walking and running on a non-motorized, curved treadmill

ObjectiveTo determine whether exercise performed on a non-motorized, curved treadmill (NMCT) provides greater physiologic stimulus compared to a standard motorized treadmill (SMT). Study designCrossover. SettingClinical research laboratory. Participants10 healthy athletic adults. Main outcome measuresParticipants walked (1.34 m s−1) for 3 min and ran (2.24 m s−1) for 4 min on NMCT and SMT (randomized order) while metabolic data and rating of perceived exertion (RPE) were collected. Participants then identified preferred easy and moderate intensity training paces on each treadmill while blinded to speed. Repeated-measures ANOVA and Wilcoxon Signed-Rank tests were used to compare responses between treadmills. ResultsIntensity was significantly greater (P < 0.001) for NMCT than SMT [mean (95% confidence interval): Walking = 5.9(5.3,6.4) vs. 3.4(3.0,3.7) METs; Running = 10.7(9,6,11.7) vs. 7.3(6.8,7.8) METs]. Overall RPE was significantly greater (P < 0.01) on NMCT than SMT for walking [median (inter-quartile range): 7(1) vs. 6(0.8)] and running [11.5(3) vs. 8(2.5)]. Preferred speed was significantly slower on NMCT than SMT for easy [2.5(2.3,2.7) vs. 2.8(2.5,3.1) m s−1] and moderate [3.2(3.0,3.4) vs. 3.5(3.1,3.9) m s−1] intensities. ConclusionsNMCT elicits greater physiological stimulus than SMT with small, though statistically significant, changes in RPE at matched speeds. Clinicians must be aware of differences in intensity and RPE when prescribing exercise on NMCT.

Metabolic cost of locomotion during treadmill walking with blood flow restriction

We explored whether interval walking with blood flow restriction (BFR) increases net metabolic cost of locomotion in healthy young men at their optimal walking speed. We also determined whether decreased walking economy resulting from BFR might be accompanied by an increase in ventilation relative to VO2 and VCO2 . Finally, we examined possible relationships between the changes in ratings of perceived exertion (RPE) and those obtained in minute ventilation (VE ) during walking with BFR. Eighteen healthy men (age: 22·5 ± 3·4 years) performed graded treadmill exercise to assess VO2max . In a randomized fashion, participants also performed five bouts of 3-min treadmill exercise with and without BFR at their optimal walking speed. Walking with BFR elicited an overall increase in net VO2 (10·4%) compared with that seen in the non-BFR condition (P<0·05). The participants also demonstrated greater VE and VE /VO2 values while walking with BFR (P<0·05). Conversely, VE /VCO2 was similar between conditions at each walking bout. We found no significant correlation between the changes in VE and RPE induced by walking with BFR (r = 0·38, P>0·05). Our results indicate that (i) BFR decreases net walking economy in healthy young men, even at their optimal walking speed; (ii) heightened ventilatory drive may explain a small proportion of BFR effects on walking economy; and (iii) the ventilatory responses to BFR walking may be largely independent of changes in perceived exertion and are likely matched to the flux of CO2 between muscles and respiratory centres.

Fatigue Index and Fatigue Rate during an Anaerobic Performance under Hypohydrations

BackgroundSince hypohydration commonly occurs in sports, studies on anaerobic exercise performance under this condition have been extensively carried out. When describing anaerobic performance, authors usually refer to a drop in anaerobic performance as fatigue index (FI) which is conventionally calculated using peak and low power data points. Meanwhile, another possible method in explaining anaerobic fatigue is using the rate constant which is derived from the exponential decline of power output known as fatigue rate (FR). Few studies have demonstrated that there was no change in anaerobic performance under mild hypohydrations.PurposeThis study aimed to compare the kinetics of power output using FI and FR of an anaerobic performance (Wingate test) under 2, 3 and 4% state of hypohydrations.MethodThirty two collegiate cyclists (age = 22±2 years; body weight = 71.45±3.43 kg; height = 173.23±0.04 cm) were matched using their baseline anaerobic peak power (APP) then randomly divided into 4 groups of EU (euhydrated), 2H, 3H and 4H respectively.ResultsAs expected the, FI, APP, anaerobic lower power (ALP) and rating of perceived exertion (RPE) did not show significant differences between and within the groups. However, the FR in 3H (0.018±0.005s−1) and 4H (0.019±0.010s−1) were significantly lower than EU (0.033±0.012s−1). Post-test FR also showed significant reduction in 3H and 4H compared to their pre-test values (p<0.05).ConclusionDespite the lack of changes in APP and RPE, subjects in 3H and 4H showed evidence of lower reduction of power output over time. The findings support earlier reports which showed no change in anaerobic performance under mild hypohydrations. The relatively lower FR suggests higher drive in maintaining power output under hypohydrations of 3 and 4% body weight.

A dopamine/noradrenaline reuptake inhibitor improves performance in the heat, but only at the maximum therapeutic dose

A maximal dose of bupropion has enabled subjects to maintain a higher power output than reported during the placebo session in the heat. Because this drug is taken in different doses it is important to know if there is a dose-response relationship with regard to exercise at high ambient temperature. Ten well-trained male cyclists ingested placebo (pla; 200 mg) or bupropion (50%, 75%, 100% of maximal dose: bup50: 150 mg; bup75: 225 mg; bup100: 300 mg) the evening before and morning of the experimental trial. Trials were conducted in 30 °C (humidity 48%). Subjects cycled for 60 min at 55% W (max) , immediately followed by a time trial to measure performance. Bup100 improved performance (pla: 33'42" ± 2'06"; bup100: 32'06" ± 1'54"; P = 0.035). Bupropion increased core temperature at the end of exercise, while heart rate was higher only in the bup100 trial (P < 0.05). No changes in rating of perceived exertion (RPE) or thermal sensation were found. Lower doses of bupropion were not ergogenic, indicating there was no dose-response effect. Interestingly, despite an increase in core temperature and improved performance in the maximal dose, there was no change in RPE and thermal sensation, suggesting an altered motivation or drive to continue exercise.

Caffeine does not alter RPE or pain perception during intense exercise in active women

Attenuated perceptions of exertion and leg pain are typically reported during exercise with caffeine ingestion, yet these responses are relatively unexplored in women. The primary aim of this study was to assess the effect of caffeine on rating of perceived exertion (RPE) and pain perception during a simulated time trial. Ten active women (age=22.1±1.9yr) completed an 8.2km “all out” time trial on each of 3days separated by at least 48h. Initially, a practice trial was completed, and participants refrained from products containing caffeine and lower-body exercise for 24h prior to subsequent trials. During exercise, heart rate (HR), RPE, and leg pain were recorded. Using a double-blind, randomized crossover design, participants ingested anhydrous caffeine and glucose (each 6mg/kg bw+each 6mg/kg bw glucose) or placebo (each 6mg/kg bw of glucose) 1h pre-exercise. Despite not altering (P>0.05) RPE, HR, or leg pain, caffeine improved (P<0.05) cycling performance (17.7±1.0min versus 18.2±1.1min) and power output (121.6±17.5W versus 114.9±17.9W) versus placebo. Caffeine’s ergogenic effects may be independent of changes in RPE or leg pain in active women performing a simulated time trial.

Self-Paced Walking within a Diverse Topographical Environment Elicits an Appropriate Training Stimulus for Cardiac Rehabilitation Patients

Purpose. To assess the effect of a self-paced walking intervention within a topographically varied outdoor environment on physiological and perceptual markers in cardiac rehabilitation (CR) patients. Methods. Sixteen phase II CR patients completed twelve self-paced one-mile walking sessions over a four-week period within a community-based CR programme. Walking velocity, heart rate (HR), and ratings of perceived exertion (RPE) were reported at eight stages throughout the self-paced walks. Results. The study showed a significant increase in walking velocity from week 1 (~4.5 km/h) to week 4 (~5.1 km/h) of the self-paced walking programme (P < .05). A significantly higher HR was also observed in week 4 (111 ± 13 b·min−1; ~69% of maximal HR) compared to week 1 (106 ± 14 b·min−1; ~65% of maximal HR, P < .001). There were no changes in the average RPE across the course of the 4-week self-paced walking programme (P > .05). Conclusion. A self-paced walking programme may elicit an appropriate training stimulus for CR patients when exercising within a diverse topographical environment. Participants completed a one-mile walk within a shorter period of time and at a higher physiological intensity than that elicited at the onset of the programme, despite no observed changes in participants' subjective perception of exertion.