Warm- and fatigue in skill acquisition and performance

Two experiments examined the effects of preliminary exercise on performance and learning of the Fitts' reciprocal tapping task. In the first experiment preliminary exercise was performed with either the preferred or nonpreferred arm. The tapping task was completed with the preferred by both groups. Low levels of preliminary exercise resulted in heightened performance for both groups, but higher levels resulted in a decrement for the group using the preferred arm. An arousal-plus-fatigue hypothesis can explain the results. A subsequent post-test without preliminary exercise showed no difference between the groups, indicating an effect on performance and not learning. In the second experiment preliminary exercise was provided by treadmill running to exhaustion. Again, a facilitatory effect of exercise was demonstrated on tapping performance even after exhaustive levels of running.     

Effects of a prolonged run on simple reaction time of well trained runners.

The aim of the present study was to examine the effect of increased arousal induced by a prolonged exercise at ventilatory threshold simple reaction time performance performed during a running task. 11 well trained triathletes completed two testing sessions within a 2-wk. period. The first session was a protocol of VO2 max determination conducted on a treadmill. This protocol was used to assess the velocity associated with ventilatory threshold (vVvt). The second session was a 90-min. running test performed at vVvt. This last session was composed of five submaximal treadmill runs (10-min. long, 0% grade) separated by four overground runs (10-min.). Before, during each treadmill run, and after exercise, subjects performed three blocks of 20 simple reaction time. Furthermore, at the end of each overground run, perceived exertion (RPE) was recorded. Analysis showed a significant impairment in Simple RT performance during the first treadmill run only. After this first run a significant effect of exercise duration on Simple RT was observed. After 40-min. of exercise a significant improvement in reaction time during exercise was recorded, Furthermore, when Simple RT was recorded at rest, there was no difference pre-exercise and postexercise. These results suggest that a simple cognitive performance could be improved during exercise, despite the negative effect of the dual task. This improvement in reaction time could be explained mainly by an increase in arousal induced by a prolonged exercise.     

Regulation of exercise intensity using ratings of perceived exertion during passive visual distraction

The purpose of this investigation was to determine if passive visual distraction altered ability to regulate exercise intensity as, assessed by ratings of perceived exertion during a 30-min. treadmill run. 10 trained females (VO2max, 52.7 ml.kg-1.min.-1) performed a graded exercise test on a treadmill to assess maximal aerobic power and rating of perceived exertion, oxygen uptake (VO2), heart rate, and running velocity at the 2.5 mmol.L-1 blood lactate concentration. Subjects then used the target rating of perceived exertion to regulate exercise intensity during a control condition, and two treatment runs with passive visual distractions. During the treatment sessions, the subjects ran on a treadmill while viewing a high-action or a low-action video with no audio. The subjects were allowed to adjust the treadmill speed throughout the run to maintain the target rating of perceived exertion; however, subjects were not allowed to view the speed setting. There were no significant differences in blood lactate concentration among the conditions for the control, low action, high action, or graded exercise test (p < or = .05). No significant differences in VO2 or running velocity were found within or among the 30-min. treatment runs and the graded exercise test. Heart rate at 5 min. of exercise during control (158 +/- 3 b.min.-1), low action (158 +/- 3 b.min.-1), and high action (159 +/- 2 b.min.-1) was significantly lower than the graded exercise test (169 +/- 3 b.min.-1). Based on the data collected, visual passive distraction did not alter regulation of intensity using ratings of perceived exertion during a 30-min. treadmill run.     

Effects of lesions of the amygdala, preoptic area, and hypothalamus on estradiol-induced activity in the female rat.

Lesions of the anterior hypothalamic nucleus and the medial preoptic area sharply attenuated enhancement of wheel running by estradiol benzoate in ovariectomized female rats. Lesions of the corticomedial amygdala had no effect on this behavior. The hormonal effects on activity were largely independent of any changes in body weight. Results of this first experiment indicated that the anterior hypothalamic and medial preoptic areas are critically involved in the induction of activity by estradiol. However, this experiment provided no support for suggestions that the corticomedial amygdala inhibits those structures that mediate the estrogenic induction of activity. In the second experiment, food deprivation was used to stimulate activity. Results of this experiment suggested that the reduction in the ability of estradiol to induce activity following anterior hypothalamic and medial preoptic lesions does not reflect a general inability to become more active.     

Effect of localized muscle fatigue on vertical ground reaction forces and ankle joint motion during running

The purpose of this study was to examine the changes in the vertical ground reaction force (VGRF) and ankle joint motion during the first 50% of the stance phase of running following fatiguing exercise of either the dorsiflexors or the invertors of the foot. VGRFs, sagittal and rearfoot kinematic data were collected from 11 female recreational runners running at 2.9 m/second on a treadmill prior to and following localized muscle fatigue of either the invertors or dorsiflexors of the right foot. Loading rate of the impact peak force significantly increased following fatiguing exercise of the dorsiflexors, while the peak magnitudes of the impact and push-off forces remained unchanged. There were significant decreases in dorsiflexion at heel contact, but no significant difference in any rearfoot motion parameters tested following dorsiflexor fatigue. Following fatiguing exercise of the invertors, impact peak magnitude, push-off peak magnitude and the rate of decline of the impact peak force significantly decreased; there was no change in the loading rate of the impact peak force. Invertor fatigue also resulted in a less inverted foot position at heel contact, but there were no significant differences in any other kinematic parameters tested. The results demonstrate that localized muscle fatigue of either the invertors or dorsiflexors can have a significant effect on the loading rates, peak magnitudes and ankle joint motion seen during running. These changes, due to localized muscle fatigue, may play a role in many common lower extremity running injuries.     

Effect of physical exercise prelabyrinthectomy on locomotor balance compensation in the squirrel monkey

This study examines the effectiveness of physical exercise, during a prepathology state, on locomotor balance compensation after subsequent unilateral labyrinthectomy in squirrel monkeys. An experimental group underwent 3 hr. of daily running exercise on a treadmill for 3 mo. prior to the surgery, whereas a control group was not exercised. Postoperatively, the locomotor balance function of both groups was tested for 3 mo. There was no significant difference in gait deviation counts in the acute phase of compensation. However, in the chronic compensation maintenance phase, the number of gait deviation counts was fewer in the exercise group, which showed significantly better performance stability.     

Time-dependent effects of treadmill exercise on aversive memory and cyclooxygenase pathway function

Exercise induces brain function adaptations and improves learning and memory; however the time window of exercise effects has been poorly investigated. Studies demonstrate an important role for cyclooxygenase-2 (COX-2) pathway function in the mechanisms underlying memory formation. The aim of present work was to investigate the effects of treadmill exercise on aversive memory and COX-2, PGE(2) and E-prostanoid receptors contents in the rat hippocampus at different time points after exercise has ended. Adult male Wistar rats were assigned to non-exercised (sedentary) and exercised (running daily for 20min, for 2weeks) groups. The inhibitory avoidance task was used to assess aversive memory and the COX-2, PGE(2) and E-prostanoid receptors (EP1, EP2, EP3 and EP4) levels were determined 1h, 18h, 3days or 7days after the last training session of treadmill exercise. The step down latency in the inhibitory avoidance, COX-2 and EP4 receptors levels were acutely increased by exercise, with a significant positive correlation between aversive memory performance and COX-2 levels. Increased EP2 content decreased PGE(2) levels were observed 7days after the last running session. The treadmill exercise protocol facilitates inhibitory avoidance memory and induces time-dependent changes on COX-2 pathways function (COX-2, PGE(2) and EP receptors).     

Familiarization to treadmill running in young unimpaired adults

This study investigated the time needed for familiarization to treadmill running. Seventeen young healthy adults, who were inexperienced on a treadmill, ran for 11 min on a treadmill at their self-selected speed. Discrete sagittal-plane angular kinematic parameters of the pelvis, hip, knee and ankle, and cadence and stride time data were captured with a three-dimensional motion analysis system at 0, 2, 4, 6, 8 and 10 min. Participants were considered familiarized to treadmill running by 6 min, as there were no significant changes in any dependent variables from this time. Furthermore, mean absolute difference scores between consecutive times were minimal (1.3 degrees ) and the average intraclass correlation coefficient [ICC(2,1)=.95] was maximal and highly reliable by this time. Future studies comparing treadmill and overground running need to provide an adequate treadmill familiarization time of at least 6 min prior to data capture of sagittal-plane kinematic events.     

Stress reactivity and exercise training in premenopausal and postmenopausal women.

Examined the influence of ovarian function on psychophysiological stress responses and determined if aerobic exercise reduced stress reactivity. Fifty premenopausal and postmenopausal women initially were subjected to a public speaking task and an ice-on-the-forehead procedure, during which time their blood pressure and heart rate were monitored and continuous blood samples were obtained. Subjects also underwent aerobic fitness evaluations with a maximum-exercise treadmill test. Subjects were then randomly assigned to a 12-week exercise program of either aerobic exercise (e.g., walking and jogging at a prescribed exercise intensity) or non-aerobic strength and flexibility training and were then reevaluated. Results indicated that postmenopausal women exhibited lower resting epinephrine levels but greater epinephrine reactivity to the speaking task compared to the premenopausal women. There were no differences between premenopausal and postmenopausal women with respect to cardiovascular or catecholamine responses during the cold challenge. Premenopausal and postmenopausal women also achieved comparable improvements in aerobic fitness. However, results of the mental stress testing were complex and provided only partial support for the role of aerobic exercise in reducing stress responses.     

Familiarisation of novice and experienced treadmill users during a running session: Group specific evidence,time and individual patterns

The elimination of familiarisation effects is a recurring topic in biomechanical testing during treadmill running among different experience levels. The two aims of this study were (i) to calculate familiarisation times of novice and experienced treadmill runners on a group level and (ii) to examine individual familiarisation patterns in order to classify those with similar characteristics. Twenty runners participated in this study by performing a treadmill running session with 3D motion capture. Familiarisation times for 9 kinematic variables among both groups (novices and experienced treadmill runners) were statistically analysed. Additionally a qualitative clustering process (supported by quantitative criteria) provided individual familiarisation patterns for all participants and variables. Group mean familiarisation times were inconsistent across variables (ranging from 3 to 14 min), with no general tendency for decreased familiarisation time in experienced compared to novice treadmill runners. The analysis of individual familiarisation patterns revealed that 30.5% were not stable after 15 min. Substantial changes compared to the initial state were observed in data sets with detected familiarisation pattern. Treadmill running experience does not affect familiarisation patterns since this process is highly individual and variable-specific. Consequently, no generalised familiarisation time can be provided and the elimination of familiarisation in biomechanical testing a priori does not seem to be possible in the first 15 min for approximately one third of the individual patterns studied. In conclusion, the common practice of collecting data subsequent to a pre-defined generalised familiarisation time ought to be replaced by measurements at several points in time during trials. This required procedure would allow for checking familiarisation patterns and fluctuations in order to exclude inappropriate data sets in future treadmill studies.     

On the stability and relevance of the exercise heart rate–music-tempo preference relationship

ObjectivesTo examine the stability of the cubic (two points of inflection) exercise heart rate–music-tempo preference relationship found by Karageorghis et al. (2011) in cycle ergometry using a different exercise modality (treadmill exercise). To advance previous related studies through the inclusion of psychological outcome variables (e.g., state attention and intrinsic motivation) and post-experiment interviews.DesignA mixed-model experimental design was employed with two within-subject factors (exercise intensity and music tempo) and a between-subjects factor (gender). The experiment was supplemented by qualitative data that were analyzed using inductive content analysis.MethodsParticipants (n = 22) exercised at six intensities (40–90% maxHRR) during which they were exposed to music tracks at four tempi and a no-music control. Music preference, affective valence, and perceived activation were assessed during the task. Immediately afterwards, an attentional focus item, the short Flow State Scale-2 and items from the Intrinsic Motivation Inventory were administered. A subsample of participants (n = 8) was interviewed using a schedule of open-ended questions.ResultsResults did not support a cubic relationship but rather a quadratic one (one point of inflection), and there was a weak association between the optimal choice of music tempo and positive psychological outcomes.ConclusionsThe range of preferred tempi for treadmill exercise (123–131 bpm) was narrower than that for cycle ergometry (125–140 bpm). Regardless of its tempo, music reduced the number of associative thoughts by ∼10% across all exercise intensities.     

Current issues and new directions in Psychology and Health: The costs and benefits of self-regulation – a call for experimental research

Abstract

This study was designed to assess the effects of exercise on psychological functioning in healthy Type A men. Seventy-three middle-aged men (M=42.2 years) were randomly assigned either to an aerobic exercise (AE) training group or to a strength and flexibility (SF) training group. Subjects completed a comprehensive psychological assessment battery prior to beginning the 12-week exercise programs, and after completing the programs. The psychological test battery included measures of depression, anxiety and stress, as well as various psychiatric symptoms. In addition, subjects underwent graded exercise treadmill tests (ETT) at both times of measurement in order to document changes in cardiorespiratory fitness. Aerobic exercise training consisted of walking, jogging or stair-climbing at an intensity of at least 70% of initial measured maximal oxygen consumption (VO₂max determined during the treadmill test). Strength and flexibility training consisted of circuit Nautilus training with no aerobic exercise. Results at the conclusion of the 12-week programs indicated that [Vdot]O₂max for the AE group increased by 15%, while the SF group did not change. Both groups improved on measures of psychological well-being; however, there were no differential effects of the two exercise programs on measures of psychological functioning. These results suggest that improved cardiovascular fitness is not necessary for psychological improvement among exercise participants.     

Different types of exercise induce differential effects on neuronal adaptations and memory performance

Different exercise paradigms show differential effects on various forms of memory. We hypothesize that the differential effects of exercises on memory performance are caused by different neuroplasticity changes in relevant brain regions in response to different exercise trainings. We examined the effects of treadmill running (TR) and wheel running (WR) on the Pavlovian fear conditioning task that assesses learning and memory performance associated with the amygdala (cued conditioning) and both the amygdala and hippocampus (contextual conditioning). The skeletal muscle citrate synthase activity, an indicator of aerobic capacity, was elevated in rats received 4 w of TR, but not WR. While both TR and WR elevated the contextual conditional response, only TR facilitated the cued conditional response. Using a single-neuron labeling technique, we found that while both TR and MR enlarged the dendritic field and increased the spine density in hippocampal CA3 neurons, only TR showed these effects in basolateral amygdalar neurons. Moreover, both types of exercise upregulated synaptic proteins (i.e., TrkB and SNAP-25) in the hippocampus; however only TR showed similar effects in the amygdala. Injection of K252a, a TrkB kinase inhibitor, in the dorsal hippocampus or basolateral amygdala abolished the exercise-facilitated contextual or cued fear learning and memory performance, respectively, regardless of the types of exercise. In summary, our results supported that different types of exercise affect the performance of learning and memory via BDNF-TrkB signaling and neuroplasticity in specific brain regions. The brain region-specific neuronal adaptations are possibly induced by various levels of intensity/stress elicited by different types of exercise.     

Forced exercise blocks learned helplessness in the cockroach (Periplaneta americana)

For three consecutive days, two groups of adult female cockroaches (Periplaneta americana) (ns = 10) received inescapable shock. 24 hr. later one group was exposed to 10 min. of forced exercise on a treadmill while the other group received no exercise. Both groups were then run in a shuttlebox escape task. The cockroaches exposed to forced exercise did not become helpless in the shuttlebox escape task.     

Approach and withdrawal analysis of the effects of hypothalamic stimulation and lesions in rats.

In a paradigm in which rats would both initiate and terminate hypothalamic stimulation, "purely" rewarding lateral hypothalamic and "purely" aversive medial hypothalamic electrodes were identified. Subjects were then given a series of tests designed to assess the effects of brain stimulation on approach and withdrawal behaviors. Lateral hypothalamic stimulation facilitated approach behavior and suppressed withdrawal behaviors, whereas medial hypothalamic stimulation produced largely the opposite effects. No serious motor deficits due to stimulation were detected with either type of electrode. In a second experiment, the approach-withdrawal effects of bilateral lateral hypothalamic lesions were tested and found to suppress approach behaviors and facilitate withdrawal behaviors. Other neurological examinations revealed motor deficits, but these deficits do not account for the specific pattern of results observed on the approach-withdrawal tests. These approach-withdrawal phenomena are interpreted in terms of altering a natural balance between approach and withdrawl behavior facilitating systems in the lateral and medial hypothalamus, respectively.     

Different types of environmental enrichment have discrepant effects on spatial memory and synaptophysin levels in female mice

Environmental enrichment paradigms that incorporate cognitive stimulation, exercise, and motor learning benefit memory and synaptic plasticity across the rodent lifespan. However, the contribution each individual element of the enriched environment makes to enhancing memory and synaptic plasticity has yet to be delineated. Therefore, the current study tested the effects of three of these elements on memory and synaptic protein levels. Young female C57BL/6 mice were given 3h of daily exposure to either rodent toys (cognitive stimulation) or running wheels (exercise), or daily acrobatic training for 6 weeks prior to and throughout behavioral testing. Controls were group housed, but did not receive enrichment. Spatial working and reference memory were tested in a water-escape motivated radial arm maze. Levels of the presynaptic protein synaptophysin were then measured in frontoparietal cortex, hippocampus, striatum, and cerebellum. Exercise, but not cognitive stimulation or acrobat training, improved spatial working memory relative to controls, despite the fact that both exercise and cognitive stimulation increased synaptophysin levels in the neocortex and hippocampus. These data suggest that exercise alone is sufficient to improve working memory, and that enrichment-induced increases in synaptophysin levels may not be sufficient to improve working memory in young females. Spatial reference memory was unaffected by enrichment. Acrobat training had no effect on memory or synaptophysin levels, suggesting a minimal contribution of motor learning to the mnemonic and neuronal benefits of enrichment. These results provide the first evidence that different elements of the enriched environment have markedly distinct effects on spatial memory and synaptic alterations.     

Aerobic exercise in the psychological treatment of adolescents.

A small group of psychiatrically institutionalized adolescents (16 boys, 11 girls) were assigned to a three-day-per-week running/aerobic exercise program or a regular physical activity class. The complete program continued over 9 weeks, with 11 subjects remaining throughout the program. Dependent measures of body-mass index, timed performance on a one-mile run, resting, exercise, and recovery heart rates, and measures of depression, mood-states, and self-efficacy were assessed pre-, mid-, and post-9-wk. treatment and at a 4-wk. follow-up. Improvements in depression, anxiety, hostility, confused thinking, and fatigue were shown in treated girls, with increases in vigor and self-efficacy for all treated subjects.     

A normative zone of RPE ratings for use during graded exercise testing

The purposes of this investigation were to identify a zone of normality for ratings of perceived exertion (RPE) and to compare the RPE responses in patients with coronary artery disease to this zone. The zone was generated from RPE estimated during the last minute of each stage of a Bruce treadmill test in 44 normal adult men. RPE were regressed against the corresponding MET level for each exercise stage. The zone was established as the 95% confidence interval (CI) spanning the average RPE vs MET regression line. RPE estimated during the last 1.0 min. of a Bruce or Modified Balke treadmill test administered to adult men (n=37) with coronary artery disease were compared to the 95% CI zone. A total of 19 (51%) of the coronary artery disease patients estimated RPE during a progressively incremented treadmill test that were above the zone, indicating a comparatively greater than normal perception of strain for a given metabolic stress. The presently generated zone provides a practical use of RPE in the interpretation of clinical exercise tests.     

Walking and Running on the Circular Treadmill: Transition Speed and Podokinetic Aftereffects

The author compared 10 participants' self-selected walk-to-run transition speeds on a standard treadmill with those on a circular treadmill. The speed of the outer limb at walk-to-run transition on the circular treadmill and on the standard treadmill were very similar. Adaptive aftereffects from running and walking on the circular treadmill were also similar. When asked to step in place without vision, all participants inadvertently turned in circles following walking or running on the treadmill. The results of the present study suggest that the mechanisms controlling walk-to-run transitions are similar for the standard and circular treadmills and demonstrate the robust generalizability of locomotor aftereffects from running to walking. Adaptive control of speed, form, and direction may therefore share similar mechanisms for walking and running.     

Walking and running on the circular treadmill: transition speed and podokinetic aftereffects

The author compared 10 participants' self-selected walk-to-run transition speeds on a standard treadmill with those on a circular treadmill. The speed of the outer limb at walk-to-run transition on the circular treadmill and on the standard treadmill were very similar. Adaptive aftereffects from running and walking on the circular treadmill were also similar. When asked to step in place without vision, all participants inadvertently turned in circles following walking or running on the treadmill. The results of the present study suggest that the mechanisms controlling walk-to-run transitions are similar for the standard and circular treadmills and demonstrate the robust generalizability of locomotor aftereffects from running to walking. Adaptive control of speed, form, and direction may therefore share similar mechanisms for walking and running.