differently. 3 While the taper period is designed to reduce training stress and promote recovery, performance in athletic competition has been shown to induce a psychophysiological stress response irrespective of the reduction in training load (TL). Given the sensitivity of immune function to physiological
Ciara Sinnott-O’Connor, Thomas M. Comyns, Alan M. Nevill and Giles D. Warrington
Laura Yan Lan and Diane L. Gill
The influence of self-efficacy on physiological arousal and self-reported anxiety was examined in the first phase of this study. All 32 undergraduate females in the study performed five trials of both an easy task and a difficult task, with half of them performing the easy task first and half performing the difficult task first. A manipulation check revealed that the easy task clearly elicited higher self-efficacy than the difficult task. Individuals reported lower cognitive and somatic anxiety and higher self-confidence, as assessed with the CSAI-2, and had lower heart-rate increases when performing the easy (high-efficacious) task. After the subjects finished both the easy and difficult tasks, half of them were given a cognitive feedback manipulation suggesting that elevated arousal levels were typical responses of good competitors under stress. Contrary to predictions, the manipulation did not induce higher self-efficacy and the manipulation group did not differ from the no-manipulation group on self-reported anxiety scores or heart rates. The findings support Bandura's contention that self-efficacy mediates arousal changes and demonstrate the influence of self-efficacy on multidimensional anxiety measures, but fail to demonstrate any influence of a cognitive feedback manipulation on self-efficacy or subsequent stress responses.
Shawn M. Arent, Daniel M. Landers, Kathleen S. Matt and Jennifer L. Etnier
The purpose of this study was to examine the dose-response gradient of exercise-induced affective change and the role of the stress response as a contributing mechanism. Male and female participants (N = 31) completed three different resistance training protocols (40%, 70%, and 100% of 10-repetition maximum [RM]) and a no-treatment control condition. Affective responses were assessed immediately before and at 0–5, 15, 30, 45, and 60 minutes postexercise. Salivary cortisol and heart rate (HR) responses were also assessed during each condition. As predicted, moderate intensity resistance training generally produced the greatest improvements in affect (p < .05). HR and cortisol accounted for as much as 27.3% and 5.4% of the affective variance, respectively. Findings support a curvilinear dose-response relationship between intensity and affective responses, with moderate intensity training resulting in immediate, large, and enduring affective benefits. Results also suggest that moderate activation of the stress response positively influences exercise-induced affective change.
Susan K. Grimston and Ronald F. Zernicke
Physical exercise is touted as being beneficial for enhancing the functional quality of the skeletal system, as well as the cardiovascular and muscular systems. Unwise training practices, however, combined with potential risk factors may dispose an individual to a bone stress reaction (bone responses to repetitive loads within the physiological range) or stress fracture (frank fracture of a bone from clinically significant stress reactions that produce structural failure). Here, we trace the terms that have been used to describe these injuries and recount the etiology of stress reactions and fractures. Epidemiological data have been reported for military and athletic populations, and in many instances recurring risk factors have been identified, both those that can be modified and those that cannot. In this paper, we review epidemiological data and potential risk factors for stress fractures and summarize current thought about the treatment and prevention of these exercise-related injuries.
W. Jack Rejeski, Edward Gregg, Amy Thompson and Michael Berry
In this investigation, we examined the role of acute aerobic exercise (AE) in buffering physiological responses to mental stress. Twelve trained cyclists participated in three counterbalanced treatment conditions on separate days: attention control, light exercise (50% of VO2max for 30 min), and heavy exercise (80% of VO2max for 60 min). After a 30-min rest period following each condition, subjects completed a modified Stroop task. Blood pressure (BP) and heart rate (HR) were monitored for (a) baseline responses, (b) task reactivity, and (c), 5 min of recovery following the stressor. Mean arterial pressure (MAP) revealed that reactivity was attenuated by both heavy- and light-exercise conditions as compared to responses in the control condition. Moreover, heavy exercise was more effective in reducing MAP reactivity than light exercise. Systolic BP during the task was significantly higher in the control and light-exercise conditions than following heavy exercise; diastolic BP was significantly higher in the control condition than in either exercise condition. There were no significant effects for HR. These results suggest that there is a dose-response relationship between acute AE and the attenuation of psychophysiological reactivity during stress.
Nicholas D. Gilson, Caitlin Hall, Angela Renton, Norman Ng and William von Hippel
office environment at our laboratory. We also compared hypothalamus–pituitary–adrenal axis stress response via salivary cortisol samples taken at the start and end of each workday, based on the rationale that the magnitude of the typical diurnal decrease in cortisol between these 2 time points was
Zenzi Huysmans and Damien Clement
risk for athletic injury ( Williams & Andersen, 1998 ). As outlined by Williams and Andersen’s ( 1998 ) stress-injury model, history of stressors, coping resources, and personality factors will moderate the stress response to a potentially stressful situation and subsequently alter susceptibility to
John Quindry, Lindsey Miller, Graham McGinnis, Brian Kliszczewiscz, Dustin Slivka, Charles Dumke, John Cuddy and Brent Ruby
Previous research findings indicate that environmental temperature can influence exercise-induced oxidative-stress responses, although the response to variable temperatures is unknown. The purpose of this study was to investigate the effect of warm, cold, and “neutral,” or room, environmental temperatures on the blood oxidative stress associated with exercise and recovery. Participants (N = 12, age 27 ± 5 yr, VO2max = 56.7 ± 5.8 ml · kg-1 · min-1, maximal cycle power output = 300 ± 39 W) completed 3 exercise sessions consisting of a 1-hr ride at 60% Wmax, at 40% relative humidity in warm (33 °C), cold (7 °C), and room-temperature environments (20 °C) in a randomized crossover fashion. Rectal core temperature was monitored continually as participants remained in the respective trial temperature throughout a 3-hr recovery. Blood was collected preexercise and immediately, 1 hr, and 3 hr postexercise and analyzed for oxidative-stress markers including ferric-reducing ability of plasma (FRAP), Trolox-equivalent antioxidant capacity (TEAC), lipid hydroperoxides, and protein carbonyls. Core temperature was significantly elevated by all exercise trials, but recovery core temperatures reflected the given environment. FRAP (p < .001), TEAC (p < .001), and lipid hydroperoxides (p < .001) were elevated after warm exercise while protein carbonyls were not altered (p > .05). These findings indicate that moderate-intensity exercise and associated recovery in a warm environment elicits a blood oxidative-stress response not observed at comparable exercise performed at lower temperatures.
This study investigated the effect of psychological pressure on spinal reflex excitability. Thirteen participants performed a balancing task by standing on a balance disk with one foot. After six practice trials, they performed one nonpressure and one pressure trial involving a performance-contingent cash reward or punishment. Stress responses were successfully induced; state anxiety, mental effort, and heart rates all increased under pressure. Soleus Hoffmann reflex amplitude in the pressure trial was significantly smaller than in the nonpressure trial. This modification of spinal reflexes may be caused by presynaptic inhibition under the control of higher central nerve excitation under pressure. This change did not prevent 12 of the 13 participants from successfully completing the postural control task under pressure. These results suggest that Hoffmann reflex inhibition would contribute to optimal postural control under stressful situations.
Benjamin James and David Collins
A qualitative investigation was conducted to identify sources of stress and the self-presentational mechanism that may underpin them during competition. Twenty athletes described factors they perceived as stressful during competition. Content analysis revealed eight general sources of stress, including significant others, competitive anxiety and doubts, perceived readiness, and the nature of the competition (e.g., importance). Two thirds (67.3%) of all stress sources appeared to heighten the athletes’ need to present themselves in a favorable way to the audience. Factors that increased perceived likelihood of poor personal performance lowered the athletes’ ability to convey a desired image to their audience. Social evaluation and self-presentation was also identified as a general source of stress in its own right. These findings suggest that (a) these athletes were sensitive about the impressions people form of them during competition, and (b) stress responses maybe triggered by factors that primarily influence the self-presentational implications of performance.