Optic Flow Influences Perceived Exertion and Distance Estimation but not Running Pace

Having the Heart to Exercise Control: Cardiac Interoception Influences Self-Paced Exercise Regulation

The aim of this study was to examine the role of cardiac interoception on self-regulated (Experiment 1) and externally prescribed (Experiment 2) exercises. Cardiac interoception was assessed using heartbeat tracking and discrimination tasks in both experiments. Based on heartbeat discrimination performance, participants were partitioned into groups demonstrating GOOD and POOR cardiac interoceptive accuracy. In Experiment 1, 20 participants completed two self-regulated 20-min cycling tasks at two intensities (light rated physical exertion [RPE on Borg Scale = 10] vs. hard-to-very hard, RPE = 16). During self-regulated exercise, the POOR cardiac interoception group showed lower differences in their exercise work rates and physiological responses between light and hard-to-very hard intensity exercises. These differences were partly attributable to a higher work rate over the first 5 min of light intensity exercise and a higher initial rate of work in the first min of hard-to-very hard intensity exercise. In Experiment 2, 15 participants completed an externally prescribed, constant-load cycling task performed at 80% of the peak power output, to task failure. During externally prescribed exercise, GOOD and POOR groups did not differ in their time-to-task failure nor in their physiological and perceptual responses to the exercise. Together these findings demonstrate that individual differences in interoceptive accuracy influence the regulation of self-paced exercise but do not affect externally prescribed exercise tolerance under constant load.

Redirected Attention and Impaired Recognition Memory during Exhaustive Cycling Has Implications for Information Processing Models of Effort-Regulation

Perception of internal and external cues is an important determinant of pacing behaviour, but little is known about the capacity to attend to such cues as exercise intensity increases. This study investigated whether changes in attentional focus and recognition memory correspond with selected psychophysiological and physiological parameters during exhaustive cycling.

METHODS

Twenty male participants performed two laboratory ramped cycling tests beginning at 50 W and increasing by 0.25 W/s until volitional exhaustion. Ratings of perceived exertion, heart rate and respiratory gas exchange measures were recorded during the first test. During the second test, participants listened to a list of spoken words presented through headphones at a rate of one word every 4 s. Afterwards, their recognition memory for the word pool was measured.

RESULTS

Recognition memory performance was found to have strong negative correlations with perceived exertion (p < 0.0001), percentage of peak power output (p < 0.0001), percentage of heart rate reserve (p < 0.0001), and percentage of peak oxygen uptake (p < 0.0001).

CONCLUSIONS

The results show that, as the physiological and psychophysiological stress of cycling intensified, recognition memory performance deteriorated. This might be due to impairment of memory encoding of the spoken words as they were presented, or because of a diversion of attention away from the headphones, perhaps towards internal physiological sensations as interoceptive sources of attentional load increase with exercise intensity. Information processing models of pacing and performance need to recognise that an athlete's capacity to attend to and process external information is not constant, but changes with exercise intensity.

Music Alters Conscious Distance Monitoring without Changing Pacing and Performance during a Cycling Time Trial

Athletes use their own perception to monitor distance and regulate their pace during exercise, avoiding premature fatigue before the endpoint. On the other hand, they may also listen to music while training and exercising. Given the potential role of music as a distractor, we verified if music influenced the athletes' ability to monitor the distance covered during a 20-km cycling time trial (TT20km). We hypothesized that music would elongate cyclists' perceived distance due to reduced attentional focus on exercise-derived signals, which would also change their ratings of perceived exertion (RPE). We also expected that the motivational role of music would also be beneficial in pacing and performance. After familiarization sessions, ten recreational cyclists performed an in-laboratory TT20km while either listening to music or not (control). They reported their RPE, associative thoughts to exercise (ATE), and motivation when they each perceived they had completed 2-km. Power output and heart rate (HR) were continuously recorded. Cyclists elongated their distance perception with music, increasing the distance covered for each perceived 2 km (p = 0.003). However, music reduced the error of conscious distance monitoring (p = 0.021), pushing the perceived distance towards the actual distance. Music increased the actual distance-RPE relationship (p = 0.004) and reduced ATE (p < 0.001). However, music affected neither performance assessed as mean power output (p = 0.564) and time (p = 0.524) nor psychophysiological responses such as HR (p = 0.066), RPE (p = 0.069), and motivation (p = 0.515). Cyclists elongated their distance perception during the TT20km and changed the actual distance-RPE relationship, which is likely due to a music-distractive effect. Although there was a reduced error of conscious distance monitoring, music affected neither pacing nor performance.

Pacing Decision Making in Sport and the Effects of Interpersonal Competition: A Critical Review

An athlete's pacing strategy is widely recognised as an essential determinant for performance during individual events. Previous research focussed on the importance of internal bodily state feedback, revealed optimal pacing strategies in time-trial exercise, and explored concepts such as teleoanticipation and template formation. Recently, human-environment interactions have additionally been emphasized as a crucial determinant for pacing, yet how they affect pacing is not well understood. Therefore, this literature review focussed on exploring one of the most important human-environment interactions in sport competitions: the interaction among competitors. The existing literature regarding the regulation of exercise intensity and the effect of competition on pacing and performance is critically reviewed in this paper. The PubMed, CINAHL and Web of Science electronic databases were searched for studies about pacing in sports and (interpersonal) competition between January 2000 to October 2017, using the following combination of terms: (1) Sports AND (2) Pacing, resulting in 75 included papers. The behaviour of opponents was shown to be an essential determinant in the regulation of exercise intensity, based on both observational (N = 59) and experimental (N = 16) studies. However, adjustment in the pacing response related to other competitors appears to depend on the competitive situation and the current internal state of the athlete. The findings of this review emphasize the importance of what is happening around the athlete for the outcome of the decision-making process involved in pacing, and highlight the necessity to incorporate human-environment interactions into models that attempt to explain the regulation of exercise intensity in sports and exercise.

Affective outcomes during and after high-intensity exercise in outdoor green and indoor gym settings

Outdoor exercise settings promote greater psychological well-being than synthetic equivalents, although the influence of the exercise context has not been investigated at high exercise intensities. This study compared the psychological effects of high-intensity exercise in outdoor green and indoor gym settings in 22 adult runners using a randomized repeated measures design. Affect and perceived exertion were assessed before, during, and after a 6000-m run with the second half completed at maximum effort. Perceived exertion and activation increased in a progressive manner from baseline to 6000 m, and decreased during the 10-min recovery post-run. Non-significant reductions in affective valence were observed between 3000 and 6000 m, followed by a significant increase post-run. Outcomes did not differ at any time point between the settings. This study suggested that regular runners experience positive affective responses during and after high-intensity exercise in both a natural outdoor environment and an indoor gym.

The Motivational Influence of Milestone Times on 10-km Running Performance

To date, little research has been conducted to evaluate the potentially motivating effect of completing a race at a specific "milestone" finishing time. As this is difficult to perform in a laboratory setting, we examined 10-km runners from a large cohort to see if they were more likely to complete a race before rather than after a set milestone time (40:00, 45:00, and 50:00). Frequency distributions for finishers of each sex were created in 30-second time groups, with ideal normal distributions modeled based on this data. The actual time group frequencies were compared to the "expected" values from the modeled normal distributions. We included time groups that contained at least 1,000 finishers, thus were constrained to 36:00 - 52:00 for men and 43:30 to 52:00 for women. A total of 180,731 men and 53,047 women were included in the analysis. Men showed significant positive deviations (more finishers than expected) in the 39:30-40:00, 44:30-45:00, and 48:30-50:00 time groups (3 groups); they showed significant negative deviations only at 40:00-40:30 and 50:00-50:30. Women only showed significant positive time group deviations from 48:30-50:00 (1 group) with no significant negative deviations. In conclusion, despite the relatively arbitrary nature of milestones, they appear to exert a motivational influence on 10-km runners.

Conscious distance monitoring and perceived exertion in light-deprived cycling time trial

The monitoring of distance is crucial to calculate the metabolic requirement and the ratings of perceived exertion (RPE) for a given exercise bout. Visual cues provide valuable information for distance estimation, navigation and orientation. The present study investigated if light deprivation may affect the conscious monitoring of distance, RPE and associative thoughts to exercise (ATE) during a 20-km cycling time trial (TT20km). Eleven male, endurance cyclists performed two TT20km in illuminated-control and light-deprived laboratory. They were asked to self-report RPE and ATE when they perceived they had completed each 2km.

RESULTS

The light deprivation resulted in elongated perceived distance at each actual 2km, rather than in illuminated-control trial (P<0.05). Although there was no difference in RPE when it was plotted as a function of the perceived distance, RPE was lowered in light-deprived environment when it was plotted as a function of the actual distance (P<0.05). Additionally, ATE was lowered during TT20km in light deprivation (P<0.01); however, pacing and performance were unaffected in light-deprived environment.

CONCLUSION

Results suggest that pacing and performance were regulated through a system which was unaffected in light-deprived environment, despite the altered conscious distance monitoring and perceptive responses.

Occlusion of sight, sound and smell during Green Exercise influences mood, perceived exertion and heart rate

This study's aim was to identify the relative contribution of sight, sound and smell to the Green Exercise effect. It was hypothesised that visual occlusion while exercising in a natural environment would have the greatest diminishing effect on perceived exertion and mood compared to auditory and olfactory occlusion. Twenty-nine healthy participants were randomly assigned to one of the three groups: visual (n = 10), auditory (n = 9) and olfactory occlusion (n = 10). Each performed six, 5-min bouts of exercise alternating between full sensory and occlusion. Rate of perceived exertion (RPE), heart rate (HR) and mood were recorded at the end of each bout. Sensory-occlusion increased mood, RPE and HR; effects were strongest when sounds were blocked but virtually absent when vision was blocked. During sensory occlusion, mood changes were characterised by increased Fatigue and Confusion, and reduced Vigour. Reductions in Tension and Vigour and increases in Fatigue were found during full sensory exercise, consistent with previous research findings.