Exercise Rating Of Perceived Exertion Research Articles

Relationship Between Perceived Exercise Intensity And Natural Killer Cell Mobilization After Exercise

The mobilization of lymphocyte subsets into and out of peripheral blood after dynamic exercise is well-characterized. While the magnitude of this effect has been shown to relate to objective measures of exercise intensity, the role of perceived intensity of the exercise bout is less understood. PURPOSE: Determine if the change in frequency of peripheral blood lymphocytes following acute dynamic exercise is associated with ratings of perceived exertion (RPE). METHODS: 18 physically active adults (8 women, aged 27.7 ± 4.4 years) cycled on a stationary bicycle 30 min at a power sufficient to elicit 80% of their age predicted maximum heart rate (HR). Heart rate and RPE (Borg 6-20 scale) was recorded each minute. Venous blood sampled pre- and post-exercise was analyzed by flow cytometry, and the relative change in lymphocyte subset frequency was calculated post-exercise relative to pre-exercise. The relationship between change in lymphocyte subset frequency with RPE in the final minute of exercise (RPE-end), or HR in final minute of exercise (HR-end), was assessed by linear regression. RESULTS: RPE-end significantly predicted the change in NK-cell frequency post-exercise, where RPE-end was higher in those displaying a greater mobilization (b = 40.41, SE = 17.28, p = .034, R2 = .267). Likewise, RPE-end predicted the increase in cytotoxic CD56dim NK-cells (b = 43.81, SE = 18.73, p = .034, R2 = .267). Analyzing subsets of CD56dim NK-cells differentiated by expression of inhibitory NKG2A and killer cell immunoglobulin-like receptor CD158b revealed RPE-end predicted the change in low- (b = 37.26, SE = 15.77, p = .032, R2 = .271), medium- (b = 43.03, SE = 18.41, p = .034, R2 = .267), and high-differentiated (b = 52.08, SE = 21.78, p = .030, R2 = .276) subsets. RPE-end did not significantly predict change in CD4 or CD8 T-cell subsets. HR-end did not significantly predict change in frequency of any lymphocyte subset. CONCLUSIONS: End of exercise RPE, but not HR, significantly predicted changes in the frequency of NK-cells in peripheral blood post-exercise. Although the current results are limited by the small sample, they suggest a role for the perception of exercise intensity in predicting immune responses to exercise.

The Impact Of Short-Term Hot Water Immersion On Heat Acclimation And Thermotolerance

BACKGROUND: Environmental heat stress increases physiological strain during exercise in non-acclimated individuals. Heat acclimation (HA) protocols are often used as countermeasures to preserve physiological function during exercise in the heat. Passive heat strategies could be a potential method of HA that reduces excess physical exertion prior to activity or relocation. PURPOSE: To determine the effect of hot water immersion (HWI) on heat acclimation and thermotolerance. METHODS: 6 males (Age: 23.8 ± 1.5; VO2max: 45.0 ± 7.5 mL/kg/min.) participated in a crossover, counterbalanced study with a four-week washout between conditions. Heat stress tests (HST) were performed PRE and POST acclimation sessions and consisted of 45 min of cycling at 50% of VO2max in 40 °C, 40% RH. Acclimation sessions were either three consecutive bouts of HWI or traditional heat-exercise training (TRAD). HWI sessions consisted of 40 min of submersion at 40 °C. TRAD sessions consisted of 40 min of cycling at 50% VO2max in 40 °C, 40% RH. Core body temperature (Tcore), heart rate (HR), rate of perceived exertion (RPE), and thermal sensation (TSS) were recorded during HSTs. Blood was drawn PRE and POST HST to determine change in plasma volume. Nude body mass was recorded before and after HSTs to calculate whole body sweat loss (WBSL). Tcore and HR were used to calculate physiological strain index (PSI). RESULTS: HWI decreased average HR (PRE: 158 ± 7; POST: 149 ± 7; p = < 0.05), peak HR (176 ± 7; 164 ± 5; p = < 0.05), and end exercise RPE (15.3 ± 1.8; 13.2 ± 1.9; p = < 0.05). HWI had no significant effect on resting TCore (37.2 ± 0.4; 36.8 ± 0.3; p = 0.66), end exercise TCore (38.7 ± 0.4; 38.4 ± 0.3; p = 0.20), PSI (7.8 ± 1.1; 7.0 ± 0.8; p = 0.56), or TSS (10.8 ± 1.0; 9.5 ± 1.2; p = 0.09). TRAD resulted in no significant changes in average HR (PRE: 153 ± 11; POST: 149 ± 11; p = 0.82), peak HR (170 ± 9; 165 ± 10; p = 0.51), end exercise RPE (15.1 ± 1.2; 13.3 ± 2.0; p = 0.87), PSI (9.3 ± 2.1; 8.6 ± 1.4; p = 0.73), or TSS (10.5 ± 0.8; 10.7 ± 1.5; p = 0.77). Plasma volume expansion (%) was observed in both groups (HWI: 6.6 ± 6.4; TRAD: 4.3 ± 2.0; p = 0.41). CONCLUSION: Three consecutive HWI sessions are effective in lowering HR during submaximal exercise in the heat. Compared to heat-exercise exposures, HWI is a method in which to more rapidly elicit a HA phenotype.

Dehydration Impairs Executive Function Task in Middle‐Age and Older Adults Following Endurance Exercise

Dehydration attenuates exercise and cognitive function performance in younger adults, but less is known about the impact of dehydration on the aging population. Regular exercise serves as a robust prophylactic treatment to prevent age‐related decline in physical and cognitive function. However, middle‐age and older adults often display a blunted thirst perception, which places them at risk for dehydration and subsequently may reduce the cognitive health‐related benefits of exercise.PURPOSETo examine the impact that pre‐exercise hydration status has on executive function task following endurance exercise within a middle‐age and older adult cohort.METHODSThis field study was conducted at a mass participation cycling event in Wichita Falls, Texas (ambient temperature, 26°C mean, 30°C maximum; relative humidity, 75% mean, 93% maximum). Forty‐nine recreational cyclists (55±6 y, range 44–70y) were enrolled following informed consent and were retrospectively separated into 2 groups (euhydrated, EUH; dehydrated, DEH) based on pre‐exercise hydration status. Criteria for euhydration were consistent with sports medicine consensus guidelines (urine specific gravity &lt;1.020, Usg; urine color &lt; 4 units, Ucol). All cyclists were screened for mild cognitive impairment via the validated Mini‐Cog™ assessment (4±1). At baseline, participants were familiarized with the executive function pencil‐paper test (Trail Making A and B Tests, TMT) and anthropometric measurements were recorded. Cyclists completed the TMT prior to and immediately following the event. Ratings of perceived exertion (RPE) and total exercise time were determined at the finish line. Pre‐ and post‐TMT scores were compared via paired T‐test and Cohen d effect size were recorded. All the following data are presented as mean±SD.RESULTSGroups (EUH vs DEH) did not differ in age (55±5 vs 54±8 y) or body fat percentage (12.8±5.6 vs 14.5±5.1) (p&gt;0.05). Significant differences were note in both Usg (1.015±0.004 vs 1.023±0.002) and Ucol (3±1 vs 5±1) (p&lt;0.001). Post exercise RPE (15±2 vs 17±2), total event time (362±59 vs 359±51 min), and body mass loss ( −2.0%, EUH and DEH) were similar for both groups (p&gt;0.05). After the HHH 164‐km endurance cycling event, there was a significant improvement (i.e., faster completion time) in the TMT noted in the EUH group (pre vs post, 83±24 vs 71±18 s; p&lt;0.05) but not the DEH group (pre vs post, 86±26 vs 79±22 s). Further analysis showed the Cohen d effect sizes to be moderate (0.5) in the EUH and small (0.2) in the DEH group.CONCLUSIONIn this prospective study, dehydration negatively impacted an executive function task (TMT) in middle‐age and older adults following an acute bout of prolonged, moderate‐intensity endurance exercise. This suggests that older adults should adopt adequate drinking behaviors to reduce cognitive fatigue and potentially enhance the cognitive benefits of regular exercise participation.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Effect of Pregabalin on Cardiovascular Responses to Exercise and Postexercise Pain and Fatigue in Fibromyalgia: A Randomized, Double-Blind, Crossover Pilot Study.

Pregabalin, an approved treatment for fibromyalgia (FM), has been shown to decrease sympathetic nervous system (SNS) activity and inhibit sympathetically maintained pain, but its effects on exercise responses have not been reported. Methods. Using a randomized double-blind crossover design, we assessed the effect of 5 weeks of pregabalin (versus placebo) on acute cardiovascular and subjective responses to moderate exercise in 19 FM patients. Blood pressure (BP), heart rate (HR), and ratings of perceived exertion (RPE) during exercise and ratings of pain, physical fatigue, and mental fatigue before, during, and for 48 hours after exercise were compared in patients on pregabalin versus placebo and also versus 18 healthy controls. Results. On placebo, exercise RPE and BP were significantly higher in FM patients than controls (p < 0.04). Pregabalin responders (n = 12, defined by patient satisfaction and symptom changes) had significantly lower exercise BP, HR, and RPE on pregabalin versus placebo (p < 0.03) and no longer differed from controls (p > 0.26). Cardiovascular responses of nonresponders (n = 7) were not altered by pregabalin. In responders, pregabalin improved ratings of fatigue and pain (p < 0.04), but negative effects on pain and fatigue were seen in nonresponders. Conclusions. These preliminary findings suggest that pregabalin may normalize cardiovascular and subjective responses to exercise in many FM patients.

Whole-body cooling does not compromise muscle oxidative capacity in subjects with multiple sclerosis.

Whole-body cooling improves exercise tolerance in patients with multiple sclerosis (pwMS). To be able to exercise at greater intensities and/or for longer durations with whole-body cooling, it should be examined whether this compromises skeletal muscle oxidative capacity (assessed by exercise-onset VO2 kinetics). To study the impact of whole-body cooling on exercise-onset VO2 kinetics in pwMS. From 12 pwMS (EDSS 3.5 ± 1.5) and 12 healthy age, BMI, and gender-matched subjects exercise-onset VO2 kinetics (mean response time [MRT]) and body temperature were determined under normothermic and hypothermic (pre-exercise 60-min whole-body cooling) conditions during submaximal exercise testing (two 6-min constant-load exercise bouts). Moreover, heart rate, blood lactate content, expiratory volume and ratings of perceived exertion (RPE) were assessed during exercise. Exercise heart rate (-7 ± 6 beats/min) and end-exercise body temperature (-0.9 ± 0.5°C) was significantly lower in hypothermic vs. normothermic conditions in both populations (p < 0.05). In pwMS exercise RPE was lower in hypothermic vs. normothermic condition (p = 0.056). No significantly different MRT was found between normothermic vs. hypothermic conditions in both populations. Lowering body temperature prior to endurance exercise does not affect muscle oxidative capacity in pwMS, but lowers RPE, thus making it possible to prescribe exercises of greater intensity and/or longer duration.

Effect of hand cooling on body temperature, cardiovascular and perceptual responses during recumbent cycling in a hot environment

Exercise in hot environments increases body temperature and challenges the function of cardiovascular, metabolic and thermoregulatory systems. Elevated body temperature as a consequence of prolonged and/or intense exercise impairs athletic performance and increases the risk of heat illness and serious medical conditions. Pre-exercise cooling techniques have been used to lower body temperature and increase heat storage capacity during exercise. Head, neck and wrist cooling have also been employed to reduce physiological strain in hot environments. Although the majority of these methods have proven useful, some are impractical for use during exercise when heat strain is most pronounced. Hand cooling during exercise has the potential to alleviate these impracticalities and attenuate increases in body temperature due to the hands large surface to mass ratio, low metabolic heat production, large blood supply and rapid cooling rates. Reductions in body temperature after bouts of exercise and improvements in exercise performance have been observed using various hand cooling protocols. However, the effectiveness of hand cooling during exercise in a hot environment and the mechanisms of action are unclear. The purpose of the study was to quantify physiological and perceptual responses to hand immersion in water during recumbent cycling in a hot environment. In a randomised control design 7 well-trained males (body mass 79.8 s 6.3 kg; stature 182 s 5 cm; age 23 s 3 years; recumbent cycling V I‡O2peak 41 s 5 ml•kg-1•min-1) who were naA¯ve to the study aims provided informed consent to participate in 3 trials. Participants immersed their hands in 8, 14 and 34°C water whilst cycling at an intensity (W) equivalent to 50% V I‡O2peak for 60 min in an environmental chamber maintained at 35°C 50% relative humidity. Intestinal and 4-site mean skin temperature and heart rate were monitored continuously and mean-averaged over 5 minute intervals. Rating of perceived exertion and thermal strain were assessed every 5 minutes. Data was assessed for normality and homogeneity of variance. The likelihood (% chance) of between group differences was assessed using a magnitude-based approach, Cohen's standardised difference score (d = 0.20 small, 0.5 moderate and 0.8 large effect) and 90% confidence intervals for [d]. Change in intestinal temperature was likely (84%) less in 8°C; 0.43 s 0.16°C versus 34°C; 0.55 s 0.16°C after 15 min; d = 0.73 [-0.19 to 1.65] and very likely (98%) less in 8°C; 0.78 s 0.28°C versus 34°C; 1.22 s 0.16°C after 40 min d = 1.36 [0.47 to 2.25]. Change in mean skin temperature was likely (87%) less in 8°C; -0.05 s 0.39°C versus 34°C; 0.31 s 0.46°C; d = 0.81 [0.09 to 1.71] after 5 min, very likely (98%) less after 15 min; -0.09 s 0.72°C versus 0.77 s 0.30°C; d = 1.24 [0.45 to 2.03] and onwards to cessation of exercise. Percentage of peak heart rate was likely (94%) lower in 8°C; 87 s 4% versus 34°C; 90 s 5% from 25 min onwards; d = 0.69 [0.18 to 1.20]. After 5 min of exercise rating of perceived exertion was likely (77%) lower  in 8°C; 12.6 s 1.0 versus 34°C 13.4 s 1.7; d = 0.61 [-0.36 to 1.57] but was likely similar from 25 min onwards. Perception of thermal strain was likely (92%) lower in 8°C; 6.5 s 0.5 versus 34°C; 7.2 s 0.4 after 5 min exercise; d = 0.81 [0.09 to 1.71] and was almost certainly (>99%) lower; 7.3 s 0.7 versus 8.0 s 0.7 for the remainder of the trial; d = 1.21 [0.65 to 1.77]. Similar beneficial effects were observed for 14°C versus 34°C immersion but the magnitude of the effects was smaller than 8°C immersion. Small-to-moderate differences were observed between 8°C and 14°C immersion. The findings suggest that hand cooling during fixed moderate-intensity cycling in a hot environment has the potential to alleviate increases in body temperature, cardiovascular demand and perceptions of exertion and thermal strain. Greatest effects were observed when the hands were immersed in 8°C water compared with 14°C. Augmented heat loss at the palm-water surface might enable cooler blood to return to core and shell regions; increasing the thermal gradient between active tissue and blood thus improving internal heat transfer, maintaining a wide core to skin temperature gradient and reducing heat storage. Limiting the increase in body temperature might have lowered cardiovascular demands by reducing the requirement for cutaneous vasodilation thus lowering physiological strain. These combined effects are manifested in lowered perceptions of exertion and thermal strain. The findings from this study suggest that endurance exercise in hot environments might be improved by hand cooling and future research should investigate its effectiveness during cycling and running performance.

The Comparisons of Heart Rate Variability and Perceived Exertion During Simulated Cycling with Various Viewing Devices

Sympathovagal modulation during immersion in a virtual environment is an important influence on human performance of a task. The aim of this study is to investigate sympathovagal modulation using heart rate variability and perceived exertion during exercise in a virtual reality (VR) environment. Sixteen young healthy volunteers were tested while using a stationary bicycle and maintained at an anaerobic threshold intensity for exercise sessions of approximately 10 min duration. Four randomized viewing alternatives were provided including desktop monitor, projector, head mounted device (HMD), and no simulation display. The “no simulation display” served as the control group. A quick ramp exercise test was conducted and maintained at an anaerobic threshold intensity for each session to evaluate power spectral density and rating of perceived exertion (RPE). The sampled heart rate data were rearranged by cubic spline interpolation into power spectrums spanning the ultra-low frequency (ULF) to high frequency (HF) range. A significant difference was found between the no-display and projector groups for total power (TP) and very low frequency (VLF) components. In particular, there was a significant difference when comparing HMD and no-display exercise RPE curves within 6 min of cycling and at the termination of the exercise. A significant difference was also achieved in projector vs. control group comparison at the termination of the exercise. Our results indicate that the use of HMD and the projected VR during cycling can reduce the TP and VLF power spectral density through a proposed decrease in the renin-angiotensin system, with the implication that this humoral effect may enable anaerobic exercise for longer durations through a reduction in sympathetic tone and subsequent increased blood flow to the muscles.

Comparison of Predicted vs. Actual Rating of Perceived Exertion (RPE) for a Submaximal Exercise Test

PURPOSE: To determine the proportion of individuals who over or under predict the exertion associated with a submaximal exercise test and to examine potential gender differences. METHODS: The sample consisted of 38 females and 50 males, aged 27–30 yrs. Participants completed a submaximal graded exercise test that terminated at 85%of age-adjusted maximal heart rate. Participants were asked to predict the level of exertion prior to beginning the test and were asked to give an overall session RPE immediately following the completion of the test. The predicted RPE was subtracted from the post exercise RPE and participants were classified as over predicting, under predicting or accurately predicting the post exercise RPE. RESULTS: Overall, 47% of the participants over estimated, 34% under estimated and 19% accurately estimated the exertion associated with the submaximal test. A significant (p=.014) gender difference was found in that 53% of the females over estimated the exertion compared to 42% of the males and 46% of the males under estimated the exertion compared to 18% of the females. While males were more likely to be classified as physically fit than females (56% vs. 11%), fitness was not significantly related to the likelihood of over or under estimating the exertion. CONCLUSION: These data indicate that females may be more likely to over predict the exertion associated with activity while males may be more likely to under predict the exertion associated with activity. These findings may have implications in better understanding gender differences in overall physical activity

Physical Activity Recommendations Can Be Met Using A Physically Interactive Video Game Among College Students

Although a plethora of aerobic activities are available for improving fitness, many college students do not accumulate at least 30 minutes or 150 kilocalories of moderate intensity physical activity on a daily basis, as recommended by the American College of Sports Medicine (ACSM). Identifying non-traditional aerobic activities, such as Dance, Dance Revolution (DDR; Konami of America, Inc., Redwood City, CA), a physically interactive video game, may help rectify this trend. PURPOSE To determine if participation in a physically interactive video game that emphasizes lower body movements provides a means for meeting the current physical activity recommendations. METHODS Twenty college students (7 males and 13 females; 24.0±2.6 years; 66.5±3.2 inches; 66.6±16.5 kg; VO2max: 46.2±10.7 ml*kg−1*min−1) volunteered as participants. Each participant completed a maximal graded exercise treadmill test to assess maximal oxygen uptake (VO2max), a treadmill walking protocol at a self-selected “brisk walking pace”, and a session of DDR. Heart rate (HR; Polar heart monitor), rating of perceived exertion (RPE), respiratory exchange rate (RER), oxygen consumption (VO2) via open-circuit indirect calorimetry, total caloric expenditure (TEE30), time to expend 150 kilocalories (T150), average steps per minute (S1.0), total steps (TS30), and rating of overall enjoyment (1 = not enjoyable; 5 = highly enjoyable), were recorded over 30 minutes during the treadmill and DDR sessions. Step counts were recorded using a Yamex 701 pedometer. RESULTS No significant differences were observed between treadmill walking and DDR sessions for exercise RPE (11.1±1.0 vs. 10.7±1.3), RER (0.87±0.04 vs. 0.86±0.04), or T150 (35.9±28.9 vs. 38.4±9.1 minutes). The treadmill walking session compared to DDR, generated significantly higher average exercise HR (113.0±14.2 vs. 105.4±11.3 bpm), VO2 [16.3±2.8 (36.1±6.7% VO2max) vs. 12.3±2.2 (27.3±5.3% VO2max) ml*kg−1*min−1], TEE30 (167.3±56.5 vs. 122.3±27.4 kilocalories), S1.0 (126.7±6.5 vs. 78.0±19.9 steps*min), TS30 (3799.9±195.2 vs. 2339.0±597.1 steps), and TS150 (3724.7±1119.0 vs. 2901.5±746.7 steps) (p < 0.05). A significantly higher level of enjoyment was observed for the DDR (4.1±0.9) compared to treadmill walking (3.1±1.2) (p < 0.05). CONCLUSIONS Although treadmill walking was higher intensity and greater overall energy expenditure, participants reported greater enjoyment and a similar duration to expend 150 kilocalories with DDR. This pilot study suggests that the DDR video game provides an enjoyable alternative to walking for attaining the ACSM recommended daily physical activity for healthy college students.

Physical Activity Recommendations Can Be Met Using A Physically Interactive Video Game Among College Students

Although a plethora of aerobic activities are available for improving fitness, many college students do not accumulate at least 30 minutes or 150 kilocalories of moderate intensity physical activity on a daily basis, as recommended by the American College of Sports Medicine (ACSM). Identifying non-traditional aerobic activities, such as Dance, Dance Revolution (DDR; Konami of America, Inc., Redwood City, CA), a physically interactive video game, may help rectify this trend. PURPOSE To determine if participation in a physically interactive video game that emphasizes lower body movements provides a means for meeting the current physical activity recommendations. METHODS Twenty college students (7 males and 13 females; 24.0±2.6 years; 66.5±3.2 inches; 66.6±16.5 kg; VO2max: 46.2±10.7 ml*kg−1*min−1) volunteered as participants. Each participant completed a maximal graded exercise treadmill test to assess maximal oxygen uptake (VO2max), a treadmill walking protocol at a self-selected “brisk walking pace”, and a session of DDR. Heart rate (HR; Polar heart monitor), rating of perceived exertion (RPE), respiratory exchange rate (RER), oxygen consumption (VO2) via open-circuit indirect calorimetry, total caloric expenditure (TEE30), time to expend 150 kilocalories (T150), average steps per minute (S1.0), total steps (TS30), and rating of overall enjoyment (1 = not enjoyable; 5 = highly enjoyable), were recorded over 30 minutes during the treadmill and DDR sessions. Step counts were recorded using a Yamex 701 pedometer. RESULTS No significant differences were observed between treadmill walking and DDR sessions for exercise RPE (11.1±1.0 vs. 10.7±1.3), RER (0.87±0.04 vs. 0.86±0.04), or T150 (35.9±28.9 vs. 38.4±9.1 minutes). The treadmill walking session compared to DDR, generated significantly higher average exercise HR (113.0±14.2 vs. 105.4±11.3 bpm), VO2 [16.3±2.8 (36.1±6.7% VO2max) vs. 12.3±2.2 (27.3±5.3% VO2max) ml*kg−1*min−1], TEE30 (167.3±56.5 vs. 122.3±27.4 kilocalories), S1.0 (126.7±6.5 vs. 78.0±19.9 steps*min), TS30 (3799.9±195.2 vs. 2339.0±597.1 steps), and TS150 (3724.7±1119.0 vs. 2901.5±746.7 steps) (p < 0.05). A significantly higher level of enjoyment was observed for the DDR (4.1±0.9) compared to treadmill walking (3.1±1.2) (p < 0.05). CONCLUSIONS Although treadmill walking was higher intensity and greater overall energy expenditure, participants reported greater enjoyment and a similar duration to expend 150 kilocalories with DDR. This pilot study suggests that the DDR video game provides an enjoyable alternative to walking for attaining the ACSM recommended daily physical activity for healthy college students.

RPE during prolonged cycling with and without carbohydrate ingestion in boys and men.

To examine the effect of prolonged cycling on ratings of perceived exertion (RPE) in boys and men and whether carbohydrate (CHO) ingestion would lower RPE during exercise. Ten boys (9-10 yr) and 10 men (20-25 yr) cycled for 60 min at approximately 70% VO2peak on two occasions. In a double-blind, counterbalanced design, a total volume of 24 mL.kg(-1) body mass of either a 6% CHO-electrolyte (CT) or flavored water (WT) beverage was consumed intermittently before and during exercise in each trial. Oxygen consumption (VO2), ventilation (VE), respiratory rate (RR), RPE (Borg's 6-20 scale), and heart rate (HR) were recorded periodically throughout exercise. Plasma glucose (GLU) was determined before and after exercise. Postexercise GLU was not different between age groups but higher (P<0.001) during CT (5.6 +/- 0.2 mmol.L(-1)) compared with WT (4.7 +/- 0.1 mmol.L(-1)). CHO ingestion had no effect (P>0.05) on VO2, VE, RR, or RPE in either group. RR during exercise was higher (P<0.01) in boys (39.0 +/- 2.2 breaths.min(-1)) than in men (30.9 +/- 1.3 breaths.min(-1)). HR was slightly higher (P=0.047) during CT (160 +/- 3 beats.min(-1)) compared with WT (156 +/- 4 beats.min(-1)) and increased less over time (P<0.01) in boys compared with men. RPE at 5 min of exercise was similar (P>0.05) between boys (11.8 +/- 0.7) and men (12.0 +/- 0.7) but increased faster (P<0.01) over time in boys. The average exercise RPE was higher (P<0.01) in boys (15.8 +/- 0.5) than in men (14.0 +/- 0.4). The higher and faster increase in RPE during exercise in boys, compared with men, may reflect a sensitivity to RR that outweighed any effect of CHO ingestion on RPE.