Introduction: In a recent publication Swart et al. differentiated between physical sensations and the psychic sensations generated during exercise, measured by an adapted RPE scale (P-RPE) and a Task Effort Awareness scale (TEA), respectively. During a self paced 100km time trial (100km TT) and a 100km TT test performed at 70% of this intensity, they found that TEA scores were attenuated in relation to P-RPE scores, indicating a lower awareness of task effort when exercising at a lower intensity. It is unknown however whether factors other than intensity can also influence this task effort sensation. Therefore, the aim of this study was to determine whether task effort awareness would change when performing a time trial in differing environmental conditions. Methods: Ten experienced well-trained male cyclists between 18 and 45 years (393 ± 23 W) completed four 40km TT in 20, 25, 30 and 35 °C in a randomized order. Rating of physical exertion (P-RPE) and task effort awareness were recorded every 5 km. Subjects randomly assigned to different environmental conditions, while data was collected over a 2 week period. To minimize the effect of the season of the year, all data was collected within a 6 week testing period. Results: Time to complete the 40km TT increased significantly with temperature (p < 0.001) from 3874 ± 92 s in 20 degrees Celsius to 4199 ± 99 s in 35 degrees Celsius. Physical rating of perceived exertion (P-RPE) were similar during all 4 time trials in 20, 25, 30 and 35 °C, starting at approximately 16 and finishing at approximately 19 or 20. Task effort awareness levels (TEA) differed significantly between the four different temperatures, being higher in warmer environmental conditions. Differences in task effort awareness were seen from 5 km (ranging from 7.5 ± 0.4 in 20 degrees Celsius to 8.6 ± 0.2 in 35 degrees Celsius) and finished at a similar task effort awareness level of 9 to 9.5 in all the trials. Discussion: Although that self paced time trial performance decreases with a rise in environmental temperature, physical ratings of perceived exertion (P-RPE) were similar during the all 4 trials, as reported before (Swart et al., 2009; Crewe et al., 2008). In contrast, levels of task effort awareness were higher when performing the time trials in warmer environmental conditions. This finding supports the capacity of the TEA scale to differentiate between physical and psychic sensation during exercise. We hypothesize that increased afferent feed-back when cycling in warmer conditions results in higher task effort awareness levels, as seen in this study and that rising task effort is responsible for the reduction in exercise intensity in an attempt to maintain the P-RPE within the constraints of the pre-determined P-RPE template.
© Copyright 2012 17th Annual Congress of the European College of Sport Science (ECSS), Bruges, 4. -7. July 2012. Veröffentlicht von Vrije Universiteit Brussel. Alle Rechte vorbehalten.