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1.
The physiological responses of high (HF) and low fit (LF) individuals at given perceived exercise intensities were compared to ranges provided by the American College of Sports Medicine (ACSM). Participants were 7 LFand 8 HF men between the ages of 22 and 26 years. All participants performed a maximum oxygen uptake and lactate threshold test and two 15-min experimental runs in which they exercised at a constant perceived exercise intensity (RPE 13 and 17). The LF group exhibited significantly greater maximum oxygen uptake reserve ( % VO2R, p < .05) and velocity of lactate threshold (p < .01) values than HF at RPE 13 and 17. Both groups had significantly greater % VO2R and maximum heart rate values at RPE 13 in comparison with the ACSM ranges, using the highest value for the given range (p < or = .001).  相似文献   

2.
Abstract

The purpose of this study was to compare the perceptual response to absolute exercise intensities of individuals differing in cardiovascular fitness using both the RPE scale and a magnitude estimation procedure. Male (N = 34) and female (N = 41) subjects were classified as either high or low fit on the basis of predicted maximal oxygen uptake. Subjects cycled for two six-minute periods separated by a five-minute rest period. Following two minutes of cycling at 600 kpm ? min-1, work loads of 200, 400, 800, and 1000 kpm ? min-1 were presented in random order for one minute. The mean (± SD) perceptual exponent for the high fit women (1.33 ± .41) was significantly (p < .05) higher than that for the low fit women (1.06 ± .42). Perceptual exponents for the high (1.16 ± .45) and low (1.04 ± .39) fit men did not differ (p > .05). For both samples, RPE values did not differ significantly between high and low fit groups at any work load (p > .05). Heart rate was significantly (p < .05) higher at each work load for the low fit subjects. It was concluded that perceived exertion as measured by the RPE scale does not discriminate between groups of high and low fit subjects during short term exercise at low to moderate intensities, despite differences in cardiovascular strain.  相似文献   

3.
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4.
The physiological responses of high (HF) and low fit (LF) individuals at given perceived exercise intensities were compared to ranges provided by the American College of Sports Medicine (ACSM). Participants were 7 LF and 8 HF men between the ages of 22 and 26 years. All participants performed a maximum oxygen uptake and lactate threshold test and two 15-min experimental runs in which they exercised at a constant perceived exercise intensity (RPE 13 and 17). The LF group exhibited significantly greater maximum oxygen uptake reserve (%VO2R; p < .05) and velocity of lactate threshold (p < .01) values than HF at RPE 13 and 17. Both groups had significantly greater %VO2R and maximum heart rate values at RPE 13 in comparison with the ACSM ranges, using the highest value for the given range (p ≤ .001).  相似文献   

5.
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6.
The purpose of the present study was to determine the effects of 10-in [0.25-m] versus 16-in [0.41-m] wheelchair handrims on cardiorespiratory and psychophysiological exercise responses during wheelchair propulsion at selected velocities. Fifteen male paraplegics (27.0 +/- 5.5 yrs) performed three discontinuous exercise tests (ACE = arm crank ergometer; WERG = wheelchair roller ergometer) and two 1600-m performance-based track trials (TRACK) under simulated race conditions. There were no significant differences in HR, VO2, VE, HLa, or category-ratio ratings of perceived exertion (RPE) using different handrims during wheelchair propulsion at 4 km.h-1. In contrast, at 8 km.h-1 subjects demonstrated a 13% lower steady state VO2 (p less than .05) using the 10-in handrims, coincident with a 23% lower VE. Steady state HR during WERG at 8 km.h-1 using the 10-in (124.4 +/- 3.9 b.min-1) or 16-in (130.6 +/- 4.6 b.min-1) handrims were not significantly different. There were also no significant differences between ACE or WERG conditions during maximal effort for VO2 or VE. However, HRpeak during ACE was 7% higher than HRpeak during WERG16 (183 +/- 15 b.min-1 vs. 171 +/- 12 b.min-1, p less than .05), and whole blood HLa during ACE was also significantly higher (by 2.3-2.5 mmol; p less than .05) compared to WERG. There were no significant differences for HR, performance time, or RPE between trials using different handrim diameters during the 1600-m event.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

7.
The aim of this study was to compare the cycling performance of cyclists and triathletes. Each week for 3 weeks, and on different days, 25 highly trained male cyclists and 18 highly trained male triathletes performed: (1) an incremental exercise test on a cycle ergometer for the determination of peak oxygen consumption (VO2peak), peak power output and the first and second ventilatory thresholds, followed 15 min later by a sprint to volitional fatigue at 150% of peak power output; (2) a cycle to exhaustion test at the VO2peak power output; and (3) a 40-km cycle time-trial. There were no differences in VO2peak, peak power output, time to volitional fatigue at 150% of peak power output or time to exhaustion at VO2peak power output between the two groups. However, the cyclists had a significantly faster time to complete the 40-km time-trial (56:18 +/- 2:31 min:s; mean +/- s) than the triathletes (58:57 +/- 3:06 min:s; P < 0.01), which could be partially explained (r = 0.34-0.51; P < 0.05) by a significantly higher first (3.32 +/- 0.36 vs 3.08 +/- 0.36 l x min(-1)) and second ventilatory threshold (4.05 +/- 0.36 vs 3.81 +/- 0.29 l x min(-1); both P < 0.05) in the cyclists compared with the triathletes. In conclusion, cyclists may be able to perform better than triathletes in cycling time-trial events because they have higher first and second ventilatory thresholds.  相似文献   

8.
The aim of this study was to investigate the performance of an Olympic-Weightlifting session training at three times of the day on the performance related to biochemical responses. Nine weightlifters (21 ± 0.5 years) performed, in randomised order, on three Olympic-Weightlifting training (snatch, clean and jerk) sessions (08:00 a.m., 02:00 p. m., 06:00 p. m.). Blood samples were collected: before, 3 min and 48 h after each training session. Haematological parameters and markers of muscle injury were assessed. Resting oral temperature and rating of perceived exertion (RPE) were also assessed during each session. ANOVA showed that the performance was better (P < 0.001) at 02:00 p. m. with a less RPE (P < 0.01) compared to the morning and the evening sessions while there was higher (P < 0.05) oral temperature at 06:00 p. m. versus 08:00 a.m. and 02:00 p. m. Muscle damage changed immediately (without significant effect after 48 h) after the training sessions with lower values ??in the evening compared to the morning. In conclusion, the afternoon training is more effective than morning or evening sessions for weightlifters. Therefore, coaches and weightlifters should be advised to schedule their training session in the afternoon hour.  相似文献   

9.
The aim of the present study was to compare the peak anterior–posterior (Fy) and medio–lateral (Fx) ground reaction forces (GRFs) of women performing stationary running at different intensities in aquatic and dry land environments. Fourteen young women performed the stationary running exercise at three cadences (first ventilatory threshold, second ventilatory threshold and maximum effort, as determined during exercise in water) in aquatic and dry land environments. Two-way repeated measures ANOVA was used to analyse the data (α?=?.05). As a result, significantly lower peak Fy anterior, Fy posterior, Fx medial and Fx lateral values were observed for the aquatic environment, except for the Fy posterior at the first ventilatory threshold. Significant differences were observed between cadences in the peak Fy anterior, Fy posterior, Fx medial and Fx lateral values, with higher values for the cadence corresponding to maximum effort compared to the first ventilatory threshold, except for the Fy posterior and Fx medial in the aquatic environment. The results indicate that the horizontal GRFs are reduced in the aquatic environment and depend on the intensity of stationary running exercise performance.  相似文献   

10.
主观用力感觉在预测心脏康复适宜运动度中的作用   总被引：1，自引：0，他引：1  
目的:探讨主观用力感觉(RPE)在预测急性期后心梗患者(PMIP)对运动的生理和临床反应中的作用,这将有利于适宜运动强度的制定。方法:46名服用β阻断剂的男性PMIP(年龄60.9±7.5岁)5,5名未服用β阻断剂的男性PMIP(年龄63.6±7.3岁)在活动跑台上进行递增负荷实验,终止实验的标准依美国运动医学会的指南(ACSM)或病人的主观要求。运动中每30 s测量一次摄氧量(VO2)和通气量(VE)、每3 min记录一次心率(HR),血乳酸(BL)和主观用力感觉(RPE),并连续监测12导心电图。结果:两组病人在VO2,BL,VE和ST段降低与RPE的关系方面无显著差异(P>0.05)。然而,在运动实验过程中,两组病人在心率方面有显著差异(P<0.01)。无论是服用还是未服用β阻断剂的PMIP,RPE达到13都是其运动中有氧代谢向无氧代谢过渡的转折点。结论:基于以上结果,建议PMIP在运动心脏康复中感觉到"稍费力"时即不应再加大运动强度。  相似文献   

11.
The aim of this study was to determine the effects of caffeine ingestion on a 'preloaded' protocol that involved cycling for 2 min at a constant rate of 100% maximal power output immediately followed by a 1-min 'all-out' effort. Eleven male cyclists completed a ramp test to measure maximal power output. On two other occasions, the participants ingested caffeine (5 mg. kg(-1)) or placebo in a randomized, double-blind procedure. All tests were conducted on the participants' own bicycles using a Kingcycle test rig. Ratings of perceived exertion (RPE; 6-20 Borg scale) were lower in the caffeine trial by approximately 1 RPE point at 30, 60 and 120 s during the constant rate phase of the preloaded test (P <0.05). The mean power output during the all-out effort was increased following caffeine ingestion compared with placebo (794+/-164 vs 750+/-163 W; P=0.05). Blood lactate concentration 4, 5 and 6 min after exercise was also significantly higher by approximately 1 mmol. l(-1) in the caffeine trial (P <0.05). These results suggest that high-intensity cycling performance can be increased following moderate caffeine ingestion and that this improvement may be related to a reduction in RPE and an elevation in blood lactate concentration.  相似文献   

12.
Li TL  Gleeson M 《Journal of sports sciences》2004,22(11-12):1015-1024
The purpose of this study was to establish the effect of exercise at different times of day on saliva flow rate, immunoglobulin A (sIgA) concentration and secretion rate, and alpha-amylase activity, and to establish how these parameters change following a second exercise bout performed on the same day. In a counterbalanced design, eight male volunteers participated in three experimental trials separated by at least 4 days. On the trial with afternoon exercise only, the participants cycled for 2 h at 60% VO2max starting at 14:00 h. On the other two trials, participants performed either two bouts of exercise at 60% VO2max for 2 h (the first started at 09:00 h and the second started at 14:00 h) or a separate resting trial. Unstimulated saliva samples were obtained 10 min before exercise, after 58 - 60 min and during the last 2 min of exercise, and at 1 h and 2 h after exercise. Venous blood samples were taken 5 min before exercise and immediately after exercise for both bouts. Participants remained fasted between 23:00 h on the day before the trials and 18:00 h on the day of the trial. Circadian variations were found in sIgA concentration, which decreased with time from its highest value in the early morning to its lowest value in the evening, and salivary alpha-amylase secretion rate, which increased from its lowest value in the morning to its highest value in the late afternoon. Cycling at 60% VO2max for 2 h significantly decreased saliva flow rate, increased sIgA concentration and alpha-amylase activity, but did not influence sIgA secretion rate. Performing prolonged cycling at different times of day did not differentially affect the salivary and plasma hormonal responses in the short term. Performance of a second prolonged exercise bout elicited a greater plasma stress hormone response but did not appear to compromise oral immunity acutely. These findings also suggest that, in terms of saliva secretion, sIgA and alpha-amylase responses, a 3 h rest is enough to recover from previous strenuous exercise. During such exercise, sympathetic stimulation appears to be strong enough to inhibit saliva flow rate; however, it appears that it does not increase sIgA output via transcytosis.  相似文献   

13.
Excess body weight composes an important limitation to exercise in obese youth. The aim of this study was to compare the perceived exertion of obese adolescents between weight-bearing (WB; running) and non-weight-Bearing (NWB; cycling) exercises performed at moderate (55%VO2max) and high (75%VO2max) intensities. Twenty-four obese adolescents were recruited. After assessment of their body composition and physical capacities, they had to complete four isoenergetic exercise sessions: (1) a cycling session performed at 55% of their maximal capacities (NWB-55%); (2) a cycling session set at 75% (NWB-75%); (3) a running session at 55% (WB-55%); and (4) a running session at 75% (WB-75%). Perceived exertion was assessed using a visual scale at regular interval. While no significant difference between WB and NWB modalities was observed, the adolescents expressed a significantly lower rate of perceived exertion (RPE) during exercises at 55%VO2max (P < 0.0001). An intensity × modality interaction revealed that RPE was lower at 75% VO2max during NWB exercises (P < 0.05). While obese adolescents expressed lower RPE during exercise at moderate intensity whatever its modality, low level of perceived exertion has been observed during high-intensity exercises and especially during NWB. High-intensity exercise appears well tolerated in adolescents when their body weight is supported.  相似文献   

14.
The aim of this study was to assess the effect of time of day on physiological responses to running at the speed at the lactate threshold. After determination of the lactate threshold, using a standard incremental protocol, nine male runners (age 26.3 +/- 5.7 years, height 1.77 +/- 0.07 m, mass 73.1 +/- 6.5 kg, lactate threshold speed 13.6 +/- 1.6 km x h(-1); mean +/- s) completed a standardized 30 min run at lactate threshold speed, twice within 24 h (07:00-09:00 h and 18:00-21:00 h). Core body temperature, heart rate, minute ventilation, oxygen uptake, carbon dioxide expired, respiratory exchange ratio and capillary blood lactate were measured at rest, after a warm-up and at 10, 20 and 30 min during the run. In addition, the rating of perceived exertion was reported every 10 min during the run. Significant diurnal variation was observed only for body temperature (36.9 +/- 0.9 degrees C vs 37.3 +/- 0.3 degrees C) and respiratory exchange ratio at rest (0.86 +/- 0.01 vs 0.89 +/- 0.07) (P < 0.05). Diurnal variation persisted for body temperature throughout the warm-up (37.1 +/- 0.2 degrees C vs 37.5 +/- 0.3 degrees C) and during exercise (36.2 +/- 0.6 degrees C vs 38.6 +/- 0.4 degrees C), but only during the warm-up for the respiratory exchange ratio (0.85 +/- 0.05 vs 0.87 +/- 0.02) (P < 0.05). The rating of perceived exertion was significantly elevated during the morning trial (12.7 +/- 0.9 vs 11.9 +/- 1.2) (P < 0.05). These findings suggest that, despite the diurnal variation in body temperature, other physiological responses to running at lactate threshold speed are largely unaffected. However, a longer warm-up may be required in morning trials because of a slower increase in body temperature, which could have an impact on ventilation responses and ratings of perceived exertion.  相似文献   

15.
Eleven healthy men (M age = 27 years, SD = 4) completed three cycling and three walking trials in an alternating order. During each trial, participants were allowed, within 3 min, to adjust the work rate to correspond to given rating of perceived exertion (RPE) values according to the following order: RPE 11, 13, and 15. For cycling as well as walking, at each RPE there were no significant differences between mean heart rate responses across the three trials (p > .05). Mode-specific estimates for heart rate intraclass correlation coefficient and coefficient of variation ranged between .80 and .91, and 5.6% and 8.3%, respectively. This study provides absolute reliability estimates for heart rate responses when using RPE in a production format and suggests there may be RPE- (and mode) specific practice requirements for achieving a reliable heart rate response at a given RPE.  相似文献   

16.
ABSTRACT

Purpose: The effect of breakfast omission on evening high-intensity exercise performance has not previously been studied. Methods: In a randomised and counterbalanced cross-over design, 10 competitive rowers (2 male, 8 female; mean?±?SD: age 21?±?2 y, height 176?±?7?cm, weight 76?±?12?kg, body fat 19.7?±?6.8%) completed two trials (individualised carbohydrate-rich breakfast (BT; 831?±?67?kcal eaten before 09:00) and no-breakfast (NBT; extended overnight fast until 12:00)). Following ad libitum afternoon food intake, participants completed a 2000-m time-trial on a rowing ergometer between 16:30 and 18:00. Appetite and energy intake were measured throughout the day, whilst power output, time, heart rate, blood lactate, blood glucose and RPE were assessed during the time trial. Results: Appetite ratings were higher throughout the morning in NBT compared with BT, but there were no differences in ratings in the afternoon. Energy intake at lunch was greater NBT compared with BT (1236?±?594 vs 836?±?303?kcal, p?<?.05), which partly compensated for breakfast omission, although overall energy intake tended to be lower in NBT compared with BT (1236?±?594 vs 1589?±?225?kcal, p?=?.08). The time taken to complete the 2000-m time trial was greater in NBT compared with BT (469.2?±?43.4 vs 465.7?±?43.3?s; p?<?.05). No differences in heart rate, blood glucose and blood lactate responses were apparent, but overall RPE was higher in NBT compared with BT (17.8?±?0.9 vs 16.7?±?0.7?au, p?<?.05). Conclusion: The omission of a carbohydrate-rich breakfast impaired evening performance during a 2000-m rowing time trial. This finding has implications for optimising evening high-intensity exercise performance.  相似文献   

17.
Abstract

This study investigated the effects of oral taurine supplementation on cycling time to exhaustion at a fixed-intensity and thermoregulation in the heat. In a double-blind, randomised crossover design, 11 healthy males participated in a time to exhaustion test in the heat (35°C, 40% RH), cycling at the power output associated with ventilatory threshold, 2?h after ingesting: Taurine (50?mg?kg?1) or placebo (3?mg?kg?1?maltodextrin). Core and mean skin temperature, mean sweat rate, heart rate, rating of perceived exertion (RPE), thermal comfort and thermal sensation were measured during exercise and blood lactate concentration (B[La]) was measured after exercise. Taurine supplementation increased time to exhaustion by 10% (25.16 min vs. 22.43 min, p?=?0.040), end sweat rate by 12.7% (687?nL?min?1 vs. 600?nL?min?1, p?=?0.034) and decreased B[La] by 16.5% (5.75?mmol?L?1 vs. 6.85?mmol?L?1, p?=?0.033). Core temperature was lower in the final 10% of the time to exhaustion (38.5°C vs. 38.1°C, p?=?0.049). Taurine supplementation increased time to exhaustion and local sweating, while decreasing RPE and core temperature in the later stages of exercise, as well as reducing post-exercise B[La]. This study provides the evidence of taurine's role in thermoregulatory processes. These findings have implications for the short-term preparation strategies of individuals exercising in the heat. Based on these findings, a single dose of taurine 2?h prior to training or competition would provide an ergogenic and thermoregulatory effect.  相似文献   

18.
The effectiveness of a nap as a recovery strategy for endurance exercise is unknown and therefore the present study investigated the effect of napping on endurance exercise performance. Eleven trained male runners completed this randomised crossover study. On two occasions, runners completed treadmill running for 30?min at 75% ?O2max in the morning, returning that evening to run for 20?min at 60% ?O2max, and then to exhaustion at 90% ?O2max. On one trial, runners had an afternoon nap approximately 90?min before the evening exercise (NAP) whilst on the other, runners did not (CON). All runners napped (20?±?10?min), but time to exhaustion (TTE) was not improved in all runners (NAP 596?±?148?s vs. CON 589?±?216?s, P?=?.83). Runners that improved TTE after the nap slept less at night than those that did not improve TTE (night-time sleep 6.4?±?0.7?h vs. 7.5?±?0.4?h, P?r2 ? =??0.76, P?=?.001). In runners that improved TTE, ratings of perceived exertion (RPE) were lower during the TTE on NAP than CON compared to runners that did not improve (?0.4?±?0.6 vs. 0?±?0, P?=?.05). Reduced exercising sense of effort (RPE) may account for the improved TTE after the nap. In conclusion, a short afternoon nap improves endurance performance in runners that obtain less than 7?h night-time sleep.  相似文献   

19.
The aim of this study was to establish the validity of the breakpoint in breathing frequency for the assessment of the lactate threshold and the ventilatory threshold during incremental running exercise. Twelve trained runners (mean +/- s: age 29 +/- 8 years; body mass 68.7 8.8 kg; V O 2m ax 57.9 +/- 4.1 ml . kg -1 . min -1 ) performed randomly assigned incremental treadmill tests on separate days. In addition to the assessment of the V O 2m ax (Test 1), the subjects performed two standard multi-stage treadmill tests (4-min stages) for the assessment of the lactate threshold while wearing (Test 2) and not wearing (Test 3) a standard mouthpiece and noseclip arrangement. Breathing frequency was measured by a thermistor, which was positioned in the back of the mouthpiece for Test 2, and fixed 3 cm in front of the mouth using a headband and flexible wiring for Test 3. All exercise tests were recorded on videotape and mean breathing frequency and stride rate were calculated for the last minute of each stage from real-time playback of the videotapes. The breathing frequency breakpoint was determined in six subjects only for Test 2 and in five subjects only for Test 3. For Test 2, there were no differences between the breakpoint in breathing frequency (14.7 +/- 0.9 km . h - 1), the lactate threshold (14.7 +/- 0.9 km . h -1 ) and the ventilatory threshold (14.7 +/- 1.1 km . h -1 ). For Test 3, the breakpoint in breathing frequency (14.0 +/- 1.0 km . h -1 ) was not appreciably different from the lactate threshold (14.7 +/- 1.2 km . h -1 ). Hey plots showed marked interindividual differences in the responses of breathing frequency and tidal volume to exercise. In four subjects, the ventilatory threshold was mediated by a non-linear increase in tidal volume, with breathing frequency either increasing in a linear manner (n = 1) or remaining constant owing to entrainment of breathing frequency to cadence (n = 3). We conclude that the breakpoint in breathing frequency does not provide a valid method for the field-based assessment of the lactate or ventilatory thresholds in most subjects for running exercise.  相似文献   

20.
Diurnal variation in cycling performance: influence of warm-up   总被引：2，自引：0，他引：2  
We examined the effects of time of day on a cycling time trial with and without a prolonged warm-up, among cyclists who tended towards being high in "morningness". Eight male cyclists (mean +/- s: age = 24.9 +/- 3.5 years, peak power output = 319 +/- 34 W, chronotype = 39 +/- 6 units) completed a 16.1-km time trial without a substantial warm-up at both 07:30 and 17:30 h. The time trial was also completed at both times of day after a 25-min warm-up at 60% of peak power. Power output, heart rate, intra-aural temperature and category ratings of perceived exertion (CR-10) were measured throughout the time trial. Post-test blood lactate concentration was also recorded. Warm-up generally improved time trial performance at both times of day (95% CI for improvement = 0 to 30 s), but mean cycling time was still significantly slower at 07:30 h than at 17:30 h after the warm-up (95% CI for difference = 33 to 66 s). Intra-aural temperature increased as the time trial progressed (P < 0.0005) and was significantly higher throughout the time trials at 17:30 h (P = 0.001), irrespective of whether the cyclists performed a warm-up or not. Blood lactate concentration after the time trial was lowest at 07:30 h without a warm-up (P = 0.02). No effects of time of day or warm-up were found for CR-10 or heart rate responses during the time trial. These results suggest that 16.1-km cycling performance is worse in the morning than in the afternoon, even with athletes who tend towards 'morningness', and who perform a vigorous 25-min warm-up. Diurnal variation in cycling performance is, therefore, relatively robust to some external and behavioural factors.  相似文献   

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