This study analyzed an individual's ability to perceive levels of exertion of an isometric contraction. Two samples of college students were tested under magnitude production or magnitude estimation. A significant F was obtained for the magnitude production condition. An insignificant F was obtained for the magnitude estimation condition. This study concludes that subjects tested under magnitude production will perceive the 100 percent level with the least amount of error and that error will increase as the percentages descend from the 100 percent level. Subjects tested under magnitude estimation will be equally in error when perceiving percentages of a maximum contraction of the forearm flexors.

This study investigated the effects of ungraded running and graded walking as modalities of HIIT on enjoyment, perceived exertion, and affect. 29 healthy males and females (aged 23.3 ± 5.1) volunteered to participate in the study. Participants completed six visits to the laboratory: the first was a medical screening to ensure safety of the participants. For the second and third visits, participants completed two maximal treadmill exercise tests, one running and one walking. On the fourth visit, the speed needed for the run HIIT (running speed: 6.9 ± 1.2mph) and the grade needed for the walk HIIT (walking speed: 3.3 ± 0.3mph, walking grade: 17.2 ± 3.1%) experimental trials were confirmed. During the last two visits, participants completed both of the two (run HIIT and walk HIIT) randomized and counterbalanced experimental trials. Affective valence was measured at baseline and post-exercise. The single-item Feeling Scale (FS) and the Borg 6-20 RPE scale (both overall exertion and legs-only exertion) were used to measure in-task ratings of affect and exertion. The Physical Activity Enjoyment Scale (PACES) and FS were used to measure post-exercise ratings of enjoyment and affect. Results revealed a main effect for condition for post-exercise enjoyment (p < 0.001), with the run HIIT being more enjoyable. A main effect was also found for time for both overall exertion and legs-only exertion (p < 0.001 for both interactions), with the walk HIIT producing higher exertion ratings. There was a main effect for condition of legs-only exertion (p = 0.004), again walk HIIT produced higher exertion ratings. Lastly, there was a main effect when comparing 20% and 100% of total time in the run HIIT and the walk HIIT conditions, for both overall exertion and legs-only exertion (p < 0.001 for all interactions). This shows that exertion increased over time for both conditions. Exertion ratings, both overall and legs-only tended to be highest during the run HIIT condition when compared to the walk HIIT. The opposite was true for affective valence, the ratings were higher in the run HIIT condition than the walk HIIT. In conclusion, the perceptual responses in this study, which represent enjoyment, exertion and affective valence, were generally more favorable during the run HIIT condition. These results support previous findings to suggest that doing a running protocol is a well-tolerated and favorable modality for HIIT exercise.

Sprint kayaking is prominent in Europe with training methods devised and adopted from Eastern bloc training systems. There is a lack of published research on sprint kayaking locally and internationally. Consequently, the aims of this research directly address establishing a relationship between kayak specific training and the Profile of Mood States (POMS); monitoring training duration and intensity and establish a link with the POMS and Rating of Perceived Exertion (RPE); to monitor the general wellness of the kayakers. Seven elite sprint kayakers (two male, five female) with the following characteristics: age 26.5 (1.4) years, training experience 8.4 (3.7) years were part of the South African national sprint kayaking squad selected to participate in this study, based on their preparation for the 2008 Beijing Olympic Games (one male athlete did not qualify but continued to train). The females trained for the 500m K1, K2 and K4 events and the male for the 1000m K1. Three training camps (TC1, TC2, TC3) were held from 12 November to 09 December 2007, 25 February to 22 March 2008 and 14 July to 04 August 2008. RPE (Borg Scale) was recorded for each session. The 65-item POMS was completed twice a week, after half a days rest (Wednesday) and after a day and half rest (Sunday). Daily training load was calculated from RPE and session time; and an energy index calculated from the POMS vigour and fatigue scores. The Wisconsin Upper Respiratory Symptom Survey recorded illness and injury. Descriptive and Inferential Statistics, Friedman’s rank test for k correlated samples, The Wilcoxon Signed Ranks Test, Spearman rank-order correlations were used to analyse the data. Statistical significance was calculated at 5% (p=0.05) and 10% (p=0.1). The results showed higher vigour scores associated with lower RPE and low training load; and high RPE associated with higher anger, confusion, depression, fatigue and total mood disturbance scores. There was a relationship between increasing POMS scores and duration of the training camps. The POMS findings could not completely explain the relationship found between RPE and duration of the training camps. The energy index was higher pre-camp and the extended rest periods during the camps. The findings for the POMS and RPE suggested that a state of overreaching might have occurred during the camps. Monitoring of the kayakers for an extended period after the training camps would have been useful to determine whether any of these individuals became over-trained. In accordance with Kentta et al (2006), regular use of the POMS may help detect under recovery, preventing staleness and unwanted rest for extended periods. Future studies will enable a retrospective view on these results. / Dissertation (MA)--University of Pretoria, 2012. / Biokinetics, Sport and Leisure Sciences / unrestricted

No description available.

This study examines factors that determine blood lactate accumulation during exercise in order to examine the opposing theories that such accumulation occurs either as a result of muscle anaerobiosis or an "overflow" of oxygen-independent glycolysis.

In man the metabolic heat produced during physical exercise stresses the thermoregulatory system, particularly if hot, humid environmental conditions prevail. It has recently been postulated that endogenous opioids may play a role in regulating body temperature at rest and because it has also been shown that blood levels of these substances increase during exercise, the possibility exists that endogenous opioids may play a role in thermoregulation during exercise. A study was conducted in two parts to determine the thermoregulatory response during exercise with and without pharmacologic blockade of the opioid receptor. In Part I nine healthy male subjects performed 30 minutes cycling at 50 % maximal aerobic capacity in an environmentally controlled laboratory. The subjects received either placebo, 2mg or 10mg naloxone hydrochloride in a randomized double-blind crossover fashion prior to the exercise test. Rectal temperatures were recorded at one-minute intervals and cardiorespiratory parameters were measured during the test. Water loss was calculated from differences in nude body weight. In part II eight male subjects performed a graded maximal cycle ergometer test after receiving either placebo or 2mg naloxone in a randomized double-blind crossover fashion. Rectal and sublingual temperatures were recorded before and after the test and oesophageal temperature was recorded at one-minute intervals during the test. Cardiorespiratory parameters were recorded during the test. The results of Part I show that rises in rectal temperature as well as calculated water losses were similar for placebo and after the administration of both 2mg and 10mg naloxone. Similarly, during maximal exercise (Part II) the rise in rectal and oesophageal temperatures was equivalent for placebo and 2mg naloxone but sublingual temperature failed to rise during exercise following the 2mg naloxone dose. Cardiorespiratory responses did not differ between placebo and naloxone tests in both Part I and Part II of the study. These results indicate that naloxone-mediated blockade of opioid receptors does not affect rectal and oesophageal temperature responses to either submaximal or maximal exercise. Naloxone appears to selectively alter the sublingual temperature response to exercise possibly by altering local blood flow. It is concluded that insofar as naloxone induced opioid receptor blockade provides a measure of the function of the endogenous opioid system, this study suggests that the endogenous opioid system does not play a significant role in thermoregulation during exercise.

No description available.

Ishida, A, Travis, SK, Draper, G, White, JB, and Stone, MH. Player position affects relationship between internal and external training loads during Division I collegiate female soccer season. J Strength Cond Res 36(2): 513-517, 2022-The purpose of this study was to investigate how competition phase and player position affect the relationship between internal and external training loads (ITL and ETL, respectively) in collegiate female soccer. Seventeen players participated (21.8 ± 1.7 years; 165.1 ± 6.2 cm; and 63.7 ± 7.9 kg). Nineteen match-plays (10 nonconference and 9 conference) were completed during the 2019 competitive season, including 270 observations of 17 players (defenders = 5, midfielders = 9, and forwards = 3). Internal training load was assessed using session rating of perceived exertion (sRPE). External training load included total distance and high-speed running (HSR) distance. A linear mixed model was compiled with fixed effects of total distance, HSR, competition phase, and player position (defenders, midfielders, and forwards) and random effects of player. There were statistically significant main effects for total distance (p < 0.001), HSR (p = 0.047) and player position (p = 0.045) on the prediction model of sRPE. However, the main effect of competition phase did not statistically contribute to the prediction model of sRPE (p = 0.38). In the final model, total distance (p < 0.001) and player position for forwards (p = 0.008) were significant predictors of sRPE. However, there was no statistically significant fixed effect of HSR on sRPE (p = 0.15). The final model explained 60.6% of the variance in sRPE (R2 = 0.60), whereas the random effect also explained 6.1% of the variance (R2 = 0.06). Our findings indicated that total distance and player position were strong predictors of sRPE. The relationship between ITL and ETL should be monitored by player position in female soccer players.

Full-body controlled games offer the opportunity for not only entertainment, but education and exercise as well. Refined gameplay mechanics and content can boost intrinsic motivation and keep people playing over a long period of time, which is desirable for individuals who struggle with maintaining a regular exercise program. Within this gameplay genre, dance rhythm games have proven to be popular with game console owners. Yet, while other types of games utilize story mechanics that keep players engaged for dozens of hours, motion-controlled dance games are just beginning to incorporate these elements. In addition, this control scheme is still young, only becoming commercially available in the last few years. Instructional displays and clear real-time feedback remain difficult challenges. This thesis investigates the potential for full-body dance games to be used as tools for entertainment, education, and fitness. We built several game prototypes to investigate visual, aural, and tactile methods for instruction and feedback. We also evaluated the fitness potential of the game Dance Central 2 both by itself and with extra game content which unlocked based on performance. Significant contributions include a framework for running a longitudinal video game study, results indicating high engagement with some fitness potential, and informed discussion of how dance games could make exertion a more enjoyable experience.

Aim: Fatigue during team sports requiring multiple sprints can result from the combined effects of metabolic, mechanical, neurological, and immune factors. The purpose of this study was to investigate the influence of capsaicin on performance of and the physiological response to an exercise test simulating the fitness demands of team sport game conditions. Methods: This study was a placebo-controlled, crossover design. Nineteen healthy male experienced athletes age 18-30 yr consumed either 3 g/d cayenne (25.8 mg/d capsaicin) or placebo for 1 wk. Directly following the supplementation period, they completed a repeated sprint test consisting of 15 30 m maximal effort sprints on 35 s intervals. Sprint times were recorded via electronic dual-beam timing system. Fasted blood draws for interleukin-6 (IL-6) were taken at baseline prior to supplementation, 45-min pretest, and immediately post test. Heart rate (HR), blood pressure (BP), rate of perceived exertion (RPE), muscle soreness (MS), and gastrointestinal distress (GD) were measured 1-min pretest, during, posttest, and 1-min posttest. MS was also measured for 3 d posttest. Results: Relative to the placebo, capsaicin significantly reduced maximum HR by 9.3%, total average HR by 8.5%, and sprinting average HR by 6.0% (P<0.05). Capsaicin caused GD of at least 2/5 in 24.5% of subjects. There was no difference between treatments in fastest or mean sprint time, fatigue, percent change or difference in IL-6, BP, RPE, sprint or posttest MS. Conclusion: Capsaicin did not influence repeated sprint performance or the inflammatory response, but reduced HR during intense activity and causes substantial GD. / Master of Science