Knowledge of the endpoint: effect on perceptual values.

The main purpose of this study was to examine the influence of knowledge of running length (i.e., duration or distance), or the lack of it (unknown endpoint) on the ratings of perceived exertion and estimated time to exhaustion. Fourteen men were recruited for this study. Participants performed 3 tests of a similar intensity (90 % maximal aerobic velocity) and length (100 % Tlim/Dlim). However, the exercise length was differently expressed. This was either unknown or defined in terms of duration or distance. The tests with a known length were performed in a counterbalanced order. During the tests, ratings of perceived exertion, estimated time to exhaustion, and heart rate were measured then compared by using 2-way analysis of variance for repeated measures. The results show that the ratings of perceived exertion, estimated time to exhaustion, and heart rate increased significantly with exercise duration (p < .001). Moreover, the ratings of perceived exertion were significantly different between the test with an unknown running endpoint and that with a known running distance at 40, 60 and 80 % Tlim (p < .05). Therefore, athletes perceived the run as being easier during the test with an unknown running endpoint compared to the test with a known running distance. Consequently, knowledge of running length influenced the ratings of perceived exertion probably due to teleoanticipation.

[Effects of intermittent walk program on the body mass and composition in obese women]. / Effets d'un programme de marche intermittente sur la masse et la composition corporelles de femmes obèses.

UNLABELLED: The obese patients adhere weakly to rehabilitation programs; therefore the expected gains are often disappointing. This is possibly linked to the monotony of constant velocity exercises frequently proposed. Consequently, other less monotonous exercises such as the intermittent walk may be more appropriated. OBJECTIVES: The main objectives of this study were to determine if the obese women prefer a constant velocity walk or an intermittent walk, and to analyze the effects of a rehabilitation program based on the intermittent walk. MATERIALS AND METHODS: Twenty obese women were recruited. To determine the preferred walk modality, 10 obese women performed a constant velocity walk and an intermittent walk (with a similar duration and velocity) on a treadmill. The preferred walk modality was determined by lower ratings of perceived exertion. Then, these same 10 women participated in a rehabilitation program of 10 weeks (three days per week) consisting of intermittent walks. The 10 other women did not participate in a training program. RESULTS: The ratings of perceived exertion were not significantly different between the two walk modalities. However, the women who participated in a training program increased their maximal distance during a 6 min walking test and they have stabilized theirs anthropometric data. Meanwhile, the untrained women have increased their body mass, body mass index and percentage of body fat. CONCLUSION: The obese patients preferred similarly the constant velocity walk and the intermittent walk, and a rehabilitation program based on an intermittent walk is effective in avoiding the obesity aggravation.

Influence of instructions on perceptually-based ratings.

The purpose of this study was to examine the influence of the expected running duration or distance on ratings of perceived exertion (RPE) and estimated time limit (ETL) values. Thirty-nine males performed an incremental test to measure their maximal aerobic velocity (MAV). Then, the subjects realised a constant velocity test (90 % MAV) to determine their time limit (Tlim) and distance limit (Dlim). Three homogenous groups were made up. Subsequently, all the groups performed 2 similar tests: a test at 90 % MAV for 80 % Tlim and a test at 90 % MAV for 80 % Dlim, each group with different instructions: group 1 (G1) was expected to maintain the velocity for 60 % Tlim (and Dlim), while group 2 (G2) and group 3 (G3) received instructions to maintain this velocity for 80 and 100 % Tlim (and Dlim), respectively. During these tests, RPE and ETL values were collected and compared by using a three-way repeated measures ANOVA. The statistical analysis revealed no significant group or test effect on RPE and ETL (p > .05). As a consequence, in this present study, it seems that the exercise instructions have not influenced significantly the hardness of effort (i.e., RPE) and the subjective estimation of endurance (i.e., ETL).

Validity and reliability of perceptually-based scales during exhausting runs in trained male runners.

The purposes of this study were to test the validity of a recent scale based on the estimation of a time of exhaustion (entitled Estimated Time Limit scale) to predict a time limit (Tlim) and to regulate exercise intensity and to investigate the reliability of the Estimated Time Limit scale and the Ratings of Perceived Exertion (RPE) scale. 14 male runners performed one incremental test, one constant velocity test at 85% of Maximal Aerobic Velocity (MAV), one constant duration test and one retest of 15 min. on an outdoor track. The difference between Estimated Time Limit values obtained during the incremental test at 85% MAV and measured Tlim values during the constant velocity test were examined, the velocities at ETL = 13 (i.e., 15 min.) obtained during the incremental test were compared with measured velocities during the constant duration test or the retest (only the best performance was used), and RPE and Estimated Time Limit values during the constant duration test were compared with those measured during retest. The results have shown a nonsignificant correlation between Estimated Time Limit values at 85% MAV and measured Tlim values during constant velocity test. There was a significant correlation (p < .02, r = .64) between velocities at ETL= 13 and measured velocities. However, the slope and y intercept value of this regression were significantly different from those of the identity line. There was no significant difference between constant duration test and retest for the values of RPE and Estimated Time Limit with high correlations (between r = .77 and .99 for RPE scale, and r = .74 and .99 for Estimated Time Limit scale). Moreover, the regression lines were close to the identity line. The RPE and Estimated Time Limit scales are reliable, but the lack of validity for the Estimated Time Limit scale suggests that more studies must be performed before using this scale to predict Tlim and regulate exercise intensity in male runners.