Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Random walk”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,621 records · Page 90Linked to original sources
PubMed1995

An approach in the assessment of pacing hemodynamics: a comparison of VVI and DDD.

Previous methods for assessment of pacemaker hemodynamics have been limited to a rigid hospital environment. An alternative is the ambulatory ventricular function monitor (C-VEST) that, with a single injection of technetium-99m, permits the continuous measurement of relative ejection fraction (EF) and cardiac output (CO) during the activities of daily living. A study of reproducibility and a comparison of dual chamber (DDD) and fixed rate ventricular (VVI) pacing are presented. Reproducibility was assessed in six patients (4 males; mean age 58, range 27-78 years) with a mean EF of 48.5% (range 34%-62%) and DDD pacemakers, implanted for conduction abnormalities. In addition, 11 patients (7 males; mean age 55.5, range 34-75 years) with a mean EF of 48.5% (range 34%-65%), chronic complete heart block, and DDD pacemakers were used for the comparative study. After an initial multigated scan, the monitor was positioned over the left ventricle and kept in place with the plastic C-VEST. The patients undergoing the reproducibility study performed three shuttle walking tests with 20 minutes of rest in between. The patients in the comparative study were randomized to either VVI or DDD mode and performed one shuttle walking test in each pacing mode. The results confirmed that the C-VEST produces reproducible results with no significant difference in peak CO between the three shuttle walks. In addition, it confirmed previous hemodynamic studies showing that DDD pacing was superior to VVI pacing both at rest (P < 0.004) and at exercise (P < 0.002). These findings show the C-VEST to be an extremely useful tool for the hemodynamic assessment of pacemaker patients.

Adult↗
PubMed2006

Increasing child pedestrian and cyclist visibility: cluster randomised controlled trial.

STUDY OBJECTIVE: Visibility aids have the potential to reduce child pedestrian and cyclist injury but scarce data exist relating to their use or to interventions for increasing visibility aid use among children. This cluster randomised controlled trial was designed to assess the use of free visibility aids one and eight weeks after their provision among primary school children in Nottingham, UK. DESIGN: One class from each of 20 schools representing 377 children aged 7, 8, and 9 years old participated in the trial and were randomly assigned to treatment and control arms. Children in the intervention arm received two visibility aids, namely, a reflective and fluorescent slap wrap (an item that can be worn around an arm or trouser leg and is readily removed), and a reflective durable sticker in addition to educational material on the importance of being seen in the dark. Observers visited schools to observe use of reflective and fluorescent slap wraps, stickers, piping and patches on coats, and bags at baseline and at one and eight weeks after distribution of the visibility aids. The study used random effects logistic regression to calculate odds ratios (OR) and confidence intervals (CI). MAIN RESULT: The results showed that children provided with free visibility aids were significantly more likely to use any visibility aid at one week (adjusted OR 59.5, 95% CI 18.5 to 191.0) and eight weeks (adjusted OR 5.9, 95% CI 3.4 to 10.4) after distribution than children in the control arm. CONCLUSIONS: Providing free visibility aids and an educational booklet on road safety significantly increases use of visibility aids for up to eight weeks during the winter among primary school children. On the basis of an eight week follow up trial in Nottingham of 20 classes of children aged 7 to 9 years old, these results suggest that campaigns providing free visibility aids to primary school children should be encouraged.

Accident Prevention↗
PubMedDate not supplied

The effect of dynamic ankle foot orthoses on function in children with cerebral palsy.

Dynamic ankle-foot orthoses (DAFOs), with free plantarflexion, are frequently prescribed to facilitate the gross motor skills of children with cerebral palsy. Employing a randomized crossover design, this project documents the short-term effect of DAFOs in 23 ambulatory children with cerebral palsy aged 1.9 to 7.3 years. Significant improvements in crawling/kneeling, standing, and walking/running and jumping skills, as measured by using the Gross Motor Function Measure (GMFM) 88 and 66, were documented (P < 0.001). Increased motor skills with the use of DAFOs were mildly correlated with the leg length of the participants. Increasing age was negatively correlated with standing skill improvement while wearing the DAFOs. Young children who are independent walkers seem to benefit greater from the DAFOs with free plantarflexion than do children using assistive devices. Future research needs to clarify the long-term influence of the use of DAFOs on gross motor skill acquisition in young children with cerebral palsy.

Ankle↗
PubMed1992

Potentiating effects of cigarette smoking and moderate exercise on the thermic effect of a meal.

The purposes of this study were: (i) to determine the relative thermic effects of smoking and exercise in fasted and postprandial states, and (ii) to determine whether there is a weight-controlling caloric advantage of moderate exercise in the postprandial state which might be used upon smoking cessation. The subjects were ten physically fit, young, male smokers. Twenty minutes of smoking (two cigarettes) while fasted resulted in a 6.0% (12.5 kcals/3h) increase in resting metabolic rate (RMR), and 20 minutes of walking (5.8 km/h) while fasted increased post-exercise RMR by 5.8% (11.7 kcals/3h). The thermic effect of a meal (TEM) (740 ml, 874 kcals) increased RMR 21.0% (42.3 kcals/3h), which was increased to 22.1% by smoking (45.0 kcals/3h). Exercise after a meal increased RMR 29.1% (58.1 kcals/3h). Post-prandial exercise potentiated the TEM, as the energy cost was 4.0 kcals/3h greater than the sum of the thermic effect of the meal plus the thermic effect of exercise in the fasted state. Postprandial exercise expended 112.2 kcals/20 min vs. 101.6 kcals/20 min for fasted exercise, a difference of 10.4%. The difference increased to 14.6% when the post-exercise thermic effect was included. It was concluded that the thermic effect of smoking and exercise were similar in the fasted state, but were substantially different postprandially. Moderate postprandial exercise appears to offer a substantial weight-controlling advantage when compared with fasted exercise.

Adult↗
PubMed2006

Training of balance under single- and dual-task conditions in older adults with balance impairment.

BACKGROUND AND PURPOSE: Traditionally, rehabilitation programs emphasize training balance under single-task conditions to improve balance and reduce risk for falls. The purpose of this case report is to describe 3 balance training approaches in older adults with impaired balance. CASE DESCRIPTIONS: Three patients were randomly assigned to 1 of 3 interventions: (1) single-task balance training, (2) dual-task training under a fixed-priority instructional set, and (3) dual-task training under a variable-priority instructional set. OUTCOMES: The patients who received balance training under dual-task conditions showed dual-task training benefits; these training benefits were maintained for 3 months. The patient who received variable-priority training showed improvement on novel dual tasks. DISCUSSION: Older adults may be able to improve their balance under dual-task conditions only following specific types of balance training. This case report gives insight on how this intervention might be combined with more traditional physical therapy intervention.

Accidental Falls↗
PubMed2006

Effects of a postoperative resistive exercise program on the knee extension and flexion torque in children with cerebral palsy: a randomized clinical trial.

OBJECTIVE: To investigate the effects of resistive exercise on the knee extension and flexion torque production during the rehabilitation period after multilevel orthopedic surgery. DESIGN: Randomized clinical trial. SETTING: Hospital rehabilitation department. PARTICIPANTS: Thirty-nine children with spastic diplegic cerebral palsy (CP) (age range, 6-16 y), randomly allocated to an exercise group (n=19) and a control group (n=20). All received conventional physiotherapy (PT), and the exercise group also followed a resistive exercise program. INTERVENTION: A 9-month standardized home-based resistive exercise program, which started about 3 months after the surgery. MAIN OUTCOME MEASURES: The Gross Motor Functional Measurement (GMFM) assessed before (E(0)) and 1 year (E(1)) after the surgery. The Modified Ashworth Scale and the isometric and isokinetic torque of the knee extensors and flexors were evaluated at E(0), E(1), and 6 months after the surgery. RESULTS: The knee extension and flexion moments had decreased 6 months after the surgery and recovered to the preoperative level 1 year after surgery. These changes were not group dependent. CONCLUSIONS: Additional long-term, home-based, low-cost resistive exercise that starts soon after the operation of patients with CP was not more beneficial than conventional PT only, in terms of strength and GMFM.

Adolescent↗
PubMed2000

Effects of gradient and load carried on human haemodynamic responses during treadmill walking.

This study examined the effects of different loads carried and gradients, on haemodynamic and cardiovascular responses during 45 min of treadmill walking. A group of 20 male endurance-trained athletes [mean maximal oxygen uptake 61.4 (SD 4) ml x kg(-1) x min(-1)] volunteered for this study. The subjects took part in three separate trials. The first involved a backpack weighing 25 kg, the second a 35 kg backpack, and the third trial, unladen, while walking on a treadmill at a speed of 5 km x h(-1). The subjects began walking on the treadmill with the randomized load at 0% gradient. After 15 min, the gradient was increased by 5% every 15 min for a total of 45 min. The order of the loads carried was randomized among subjects. No significant differences were noted for all the variables measured attributable to loads between 25 kg and 35 kg. However, significant (P<0.05) differences were seen for all variables each time the gradient was increased. Cardiac output increased from 11.4 (SD 0.6) 1 x min(-1) at 0% to 13.6 (SD 0.8) l x min(-1) at 5% and to 17.6 (SD 1.3) l x min(-1) at 10% carrying the 35 kg load. Similarly, lactic acid concentrations in the blood increased from 2.8 (SD 0.2) to 3.1 (SD 0.6) and to 5.3 (SD 1.3) mmol x l(-1), respectively. Similar changes were observed for all variables while carrying the 25 kg load. In addition, steady states in oxygen uptake and other physiological variables were obtained throughout the course of the tests. These data suggest that during isodynamic exercise, one of the main factors determining metabolic and haemodynamic responses will be the change in gradient and to a lesser extent, the mass of the load carried.

Adolescent↗
PubMed2005

The efficacy of a pneumatic compression device in the treatment of plantar fasciitis.

Plantar fasciitis is a common foot disorder that affects more than two million Americans each year. Conservative management of plantar fasciitis is the first line of treatment by the medical specialist who frequently encounters this common foot complaint. In this study, 50 patients with plantar fasciitis of 4 weeks duration but less than 12 weeks were randomized into two groups. One group of 25 patients used the AirHeel (Aircast, Inc.) and the second group of 25 used the 1st Step prefabricated foot insert (Wrymark, Inc). Standardized weight-bearing radiographs were obtained in order to categorize the foot type: normal arch, pes planus, or pes cavus. Patients were initially evaluated and at 12 weeks they returned for a subsequent visit. The contact area of the foot with the AirHeel and 1st Step insert were similar, an increase of 27% and 26%, respectively, over the contact area barefoot. There was a noted difference in force reduction with the two devices. The AirHeel reduced the midstance force by 20.19%, as compared to the 1st Step insert which showed a 1.03% increase in midstance force. Patients with a higher initial pain score seemed to respond better initially to the AirHeel (p = 0.015) than the 1st Step insert (p = 0.035). This study demonstrates the benefits of offloading the foot at midstance with two devices to relieve the discomfort associated with plantar fasciitis. The Aircast AirHeel is a new modality for dynamic, functional treatment of proximal plantar fasciitis.

Adult↗
PubMedDate not supplied

Lack of perceived sleep improvement after 4-month structured exercise programs.

OBJECTIVE: Many middle-aged women experience decreases in their sleep quality during the menopausal transition. Physical activity has been shown to improve sleep, but few randomized, controlled trials investigating such effects in this population exist. In 164 previously low-active middle-aged women (mean age = 49.9, SD = 3.6), using a 4-month randomized, controlled trial, we examined structured exercise in the form of walking or yoga to determine the effects on perceived sleep quality. DESIGN: Participants completed body composition and fitness assessments and a battery of psychological measures, including the Pittsburgh Sleep Quality Index, at the beginning and end of a 4-month randomized, controlled exercise trial with three arms: walking, yoga, and control. RESULTS: A series of mixed-model repeated-measures univariate analyses of covariance did not reveal any statistically significant intervention effects for total sleep quality or any individual sleep-quality domain. The pattern of effect sizes indicated that the walking group tended to experience small improvements in five of the seven assessed sleep-quality domains. Residual changes in menopausal symptoms and depression were associated with residual changes in total sleep quality. However, after controlling for the effects of physical activity, only menopausal symptoms contributed a unique amount of variance in residual change in total sleep quality. CONCLUSIONS: In this study, 4-month moderate-intensity walking and low-intensity yoga programs were ineffective in yielding statistically significant improvements in sleep quality. Exercise interventions of longer durations or greater intensity may be needed for such improvements.

Aging↗
PubMed2005

A randomized intervention of physical activity promotion and patient self-monitoring in primary health care.

OBJECTIVES: To examine the effectiveness of prescription-based counseling and self-monitoring in the promotion of physical activity in primary health care. METHODS: The study was conducted in Finland during 2003-2004. Physicians from 24 health care units (N = 67) were randomized to a prescription or a non-prescription group. The patients (N = 265) were assigned to the groups according to their physician. Every other patient of the non-prescription physicians received a pedometer and a physical activity log (MON) and feedback about their 5-day-recordings, the rest served as controls (CON). PA was assessed prior and 2 and 6 months after the physician's appointment with a questionnaire. RESULTS: The mean increase in weekly overall physical activity at 2 months was 1.0 (95% CI 0.0 to 2.0) session more in the prescription group than in controls. In at least moderate-intensity physical activity, the mean difference in changes was 0.8 (95% CI 0.1 to 1.5) sessions at 2 months and 0.9 (95% CI 0.2 to 1.5) sessions at 6 months for the favor of the prescription group. Compared to controls, self-monitoring increased the weekly duration of overall PA at 2 months on average by 217 min (95% CI 23 to 411). CONCLUSIONS: Prescription can be recommended as a tool for primary health care physicians to promote physical activity. Self-monitoring with an expert feedback can be useful in increasing especially the weekly duration of overall physical activity in the short term.

Adult↗
PubMed2006

A five-week exercise program can reduce falls and improve obstacle avoidance in the elderly.

BACKGROUND: Falls in the elderly are a major health problem. Although exercise programs have been shown to reduce the risk of falls, the optimal exercise components, as well as the working mechanisms that underlie the effectiveness of these programs, have not yet been established. OBJECTIVE: To test whether the Nijmegen Falls Prevention Program was effective in reducing falls and improving standing balance, balance confidence, and obstacle avoidance performance in community-dwelling elderly people. METHODS: A total of 113 elderly with a history of falls participated in this study (exercise group, n = 79; control group, n = 28; dropouts before randomization, n = 6). Exercise sessions were held twice weekly for 5 weeks. Pre- and post-intervention fall monitoring and quantitative motor control assessments were performed. The outcome measures were the number of falls, standing balance and obstacle avoidance performance, and balance confidence scores. RESULTS: The number of falls in the exercise group decreased by 46% (incidence rate ratio (IRR) 0.54, 95% confidence interval (CI) 0.36-0.79) compared to the number of falls during the baseline period and by 46% (IRR 0.54, 95% CI 0.34-0.86) compared to the control group. Obstacle avoidance success rates improved significantly more in the exercise group (on average 12%) compared to the control group (on average 6%). Quiet stance and weight-shifting measures did not show significant effects of exercise. The exercise group also had a 6% increase of balance confidence scores. CONCLUSION: The Nijmegen Falls Prevention Program was effective in reducing the incidence of falls in otherwise healthy elderly. There was no evidence of improved control of posture as a mechanism underlying this result. In contrast, an obstacle avoidance task indicated that subjects improved their performance. Laboratory obstacle avoidance tests may therefore be better instruments to evaluate future fall prevention studies than posturographic balance assessments.

Accidental Falls↗
PubMedDate not supplied

Postoperative analgesia and recovery course after major colorectal surgery in elderly patients: a randomized comparison between intrathecal morphine and intravenous PCA morphine.

BACKGROUND AND OBJECTIVES: Intrathecal morphine is a widely used method for postoperative pain relief after major abdominal surgery. The aim of this randomized, double-blinded study was to compare intrathecal morphine and intravenous PCA morphine for postoperative analgesia and recovery course after major colorectal surgery in elderly patients. METHODS: After written informed consent, patients >70 years of age were prospectively and randomly assigned to receive either preoperative intrathecal morphine (0.3 mg) and postoperative patient-controlled (PCA) intravenous morphine (IT morphine) or PCA alone (group control). Results are presented as mean +/- SD (95% confidence interval). RESULTS: Twenty-six patients successfully completed the study in each group. In the IT morphine group, rate of awakening was delayed. Pain intensity and daily intravenous morphine consumption were significantly reduced 1 and 2 days after surgery in the IT morphine group (P < .01). Mental function (assessed by Mini Mental State and Digit Symbol Substitution Test) was similar in both groups. Episodes of postoperative delirium/confusion occurred similarly in both groups. Time to ileus resolution and time to ambulation without assistance did not differ between the 2 groups. The duration of hospitalization was 8.4 +/- 1.7 (7-11) days and 7.9 +/- 2.0 (6-9.9) days for control and IT morphine, respectively (nonstatistical difference). Patients in the IT morphine group had longer time to awakening from anesthesia and experienced more sedation. CONCLUSIONS: Intrathecal morphine, as compared with intravenous PCA morphine alone, improves immediate postoperative pain and reduces parenteral morphine consumption but does not improve postoperative recovery in elderly patients after major colorectal surgery.

Aged↗
PubMed2005

Physical therapy improves knee flexion during stair ambulation in patellofemoral pain.

PURPOSE: This study aimed to examine whether a physical therapy intervention, designed to reduce pain and improve the neuromotor control resulted in greater improvements in stance-phase knee flexion during stair ambulation in individuals with patellofemoral pain. The relationship between changes in stance-phase knee flexion and changes in pain, disability, and onset timing of individual vasti activity was also examined. METHODS: Forty participants aged 40 yr or younger diagnosed with patellofemoral pain were randomly allocated to a physical therapy (N = 21) or placebo (N = 19) treatment group. Stance-phase knee flexion was measured in two dimensions using a PEAK movement analysis system during stair ambulation. Individuals were divided into those with improvements in onset of vastus medialis obliquus (VMO) activity relative to that of the vastus lateralis (VL) of more or less than 10 ms. RESULTS: Groups were similar at baseline. After the 6-wk intervention, individuals in the physical therapy group had significantly greater changes in knee flexion at heel strike (mean difference 4 degrees, 95% CI = 2-7 degrees) and peak stance-phase knee flexion (mean difference 9 degrees, 95% CI = 5-12 degrees) than those in the placebo group. No differences were noted during stair ascent. Individuals with greater change in the onset timing of the vasti had greater improvements in stance-phase knee flexion. Changes in usual pain in the week before testing and change in the vasti onset timing were independent predictors of change in stance-phase knee flexion during stair descent, together accounting for 27-40% of the variability in knee motion. CONCLUSIONS: Physical therapy intervention resulted in significantly greater changes in knee joint motion than a placebo treatment, and these changes in knee motion were partly related to changes in pain and changes in onset timing of the vasti.

Adolescent↗
PubMed2003

A minimum on the mean number of steps taken in adaptive walks.

I consider the adaptation of a DNA sequence when mutant fitnesses are drawn randomly from a probability distribution. I focus on "gradient" adaptation in which the population jumps to the best mutant sequence available at each substitution. Given a random starting point, I derive the distribution of the number of substitutions that occur during adaptive walks to a locally optimal sequence. I show that the mean walk length is a constant:L = e-1, where e approximately 2.72. I argue that this result represents a limit on what is possible under any form of adaptation. No adaptive algorithm on any fitness landscape can arrive at a local optimum in fewer than a mean of L = e-1 steps when starting from a random sequence. Put differently, evolution must try out at least e wild-type sequences during an average bout of adaptation.

Adaptation, Biological↗
PubMed2006

Random control clinical trial on the effects of aerobic exercise training on erythrocyte levels during radiation treatment for breast cancer.

BACKGROUND: Erythrocyte changes from aerobic exercise training were examined during radiation treatment of breast cancer. METHODS: Twenty sedentary females with breast carcinoma who were ages 35 to 65 years were randomized to aerobic exercise (AE) of walking for 20 to 45 minutes, 3 to 5 times per week, at 50% to 70% of measured maximum heart rates or to placebo stretching (PS) activities 3 to 5 days per week during 7 weeks of radiation treatment. Measures were obtained 1 week before and after the radiation regimen. Serum blood analyses, through complete blood counts, measured red blood cell counts (RBC), hematocrit (HCT), and hemoglobin (HB). Peak aerobic capacity (peak VO(2)) was measured by exercise testing with oxygen uptake analysis to assess training. A Wilcoxon Mann-Whitney U test examined changes between groups (P < or = .05 for significance). RESULTS: AE peak VO(2) increased by 6.3% (P = .001) and PS decreased by 4.6% (P = .083). RBC increased in AE from 4.10 to 4.21 million cells/microL and declined in PS from 4.30 to 4.19 million cells/microL; the between-group differences were significant (P = .014). HCT increased in AE from 38.0% to 38.8% and declined in PS from 37.40% to 36.50%; the between-group differences were significant (P = .046). HB increased in AE from 12.3 to 12.4 g/dL and declined in PS from 12.25 to 11.77 g/dL; the between-group differences were significant (P = .009). CONCLUSIONS: The results of the current study suggest that moderate intensity aerobic exercise appears to maintain erythrocyte levels during radiation treatment of breast cancer compared with the declines observed in nontraining individuals. These findings suggest a safe, economical method to improve fitness and maintain erythrocytes in women during radiation treatment of breast cancer.

Adult↗
PubMed2006

Improvement of metabolic syndrome markers through altitude specific hiking vacations.

To study the influence of a 3-week hiking vacation at moderate (1700 m) and low altitude (LA) (200 m) on key-markers of the metabolic syndrome, 71 male volunteers (age 36-66 yr old) with the metabolic syndrome [according to the National Cholesterol Education Program's Adult Treatment Panel III (NCEP-ATP III) - or World Health Organization (WHO) - definition] participated in the study and were randomly assigned into a moderate altitude (MA) group (1700 m, no. 36) and a low altitude (LA) group (200 m, no. 35). The 3-week vacation program included 12 moderate- intensity guided hiking tours [4 times/week, 55-65% heart rate maximum (HRmax)] with a total exercise time of 29 h plus moderate recreational activities. Both study groups had a comparable and balanced nutrition with no specific dietary restrictions. Anthropometric, metabolic and cardiovascular parameters were measured 10-14 days before vacation, several times during the 3-week vacation, 7-10 days and 6-8 weeks after return. All participants tolerated the vacation without any adverse effects. Body weight, body fat, waist-circumference, fasting glucose, total cholesterol, LDL-cholesterol (LDL-C), plasma fibrinogen, resting systolic and diastolic blood pressure were significantly decreased over time in both study groups. In the LA group, fasting insulin and homeostasis model assessment (HOMA)-index were significantly decreased one week after return. Relative cycle ergometry performance was significantly increased after return compared to baseline. In both study groups, waist-to-hip ratio (WHR), 2-h oral glucose tolerance test (OGTT), HDL-cholesterol (HDL-C), and triglycerides remained unchanged. The 3-week vacation intervention at moderate and LA had a positive influence on all key-markers of the metabolic syndrome. No clinically relevant differences could be detected between the study groups. A hiking vacation at moderate and LA can be recommended for people with stable, controlled metabolic and cardiovascular risk factors.

Adult↗
PubMed1992

Efficacy of Tai Chi, brisk walking, meditation, and reading in reducing mental and emotional stress.

Tai Chi, a moving meditation, is examined for its efficacy in post-stressor recovery. Forty-eight male and 48 female Tai Chi practitioners were randomly assigned to four treatment groups: Tai Chi, brisk walking, mediation and neutral reading. Mental arithmetic and other difficult tests were chosen as mental challenges, and a stressful film was used to produce emotional disturbance. Tai Chi and the other treatments were applied after these stressors. After all treatments, the salivary cortisol level dropped significantly, and the mood states were also improved. In general the stress-reduction effect of Tai Chi characterized moderate physical exercise. Heart rate, blood pressure, and urinary catecholamine changes for Tai Chi were found to be similar to those for walking at a speed of 6 km/hr. Although Tai Chi appeared to be superior to neutral reading in the reduction of state anxiety and the enhancement of vigour, this effect could be partially accounted for by the subjects' high expectations about gains from Tai Chi. Approaches controlling for expectancy level are recommended for further assessment.

Adaptation, Psychological↗
PubMedDate not supplied

Enhancing theoretical fidelity: an e-mail-based walking program demonstration.

PURPOSE: To examine the extent to which theoretical fidelity, or precision in replicating theory-based recommendations, influenced the effectiveness of two walking programs based on social cognitive theory (SCT). DESIGN: Two-group randomized controlled trial. SETTING: College town in Virginia. SUBJECTS: Sixty-one sedentary adult women. INTERVENTION: Two 12-week e-mail-based walking programs were compared. The high fidelity program was designed to more precisely follow SCT recommendations for operationalizing mastery procedures than the low fidelity program, which was designed to simulate how mastery procedures were operationalized in most existing SCT-based physical activity programs. Treatment contact and walking prescription were controlled across groups. MEASURES: The 1-mile walk test of physical fitness and SCT measures were completed at baseline and posttest. Self-reported walking quantity was assessed at baseline, posttest, and 1-year follow-up. Walking logs were completed during the program. Process evaluation measures were completed at posttest. RESULTS: Fifty women completed the study. The high fidelity group improved more than twice as much as the low fidelity group on 1-mile walk test time (86 vs. 32 seconds, p < .05), goal setting (p < .05), and positive outcome expectations (p < .05) and reported greater program satisfaction (p < .01). CONCLUSION: Theoretical fidelity could advance the quality of physical activity interventions, which have often shown small effects.

Adult↗