Predictive Abilities of Balance Confidence and Fear of Falling Measures on Falls in Polio Survivors

Purposes: To determine 1) predictors of falls in adult survivors of polio and 2) if Activities-specific Balance Confidence (ABC) scale or Falls Efficacy Scale-International (FES-I) better predicted falls in this population. Methods: 415 participants completed anonymous on-line surveys, including fall history, walking status, ABC scale, FES-I, and Geriatric Depression Scale-15. Logistic and linear regressions and receiver operating curve analyses performed. Results: 69% and 81% of participants reported falls and fear of falling (FoF) (yes/no), respectively. Walking status significantly predicted falls in overall model. ABC significantly predicted falls in people who walk by separate logistic regressions. FES-I, reported FoF, and in-community walking status predicted fall frequency by linear regression. Conclusions: ABC, FES-I, and reported FoF are related to falling, especially in polio survivors who walk, with the ABC scale better predicting falls. Measures used were unhelpful in fall prediction for people who primarily use wheelchairs for locomotion.     

Walking in an Unstable Environment: Strategies Used by Transtibial Amputees to Prevent Falling During Gait

Objective

To investigate which strategies transtibial amputees use to cope with challenges of gait stability and gait adaptability, and how these strategies differ from strategies used by able-bodied controls.

Design

Cross-sectional study.

Setting

An instrumented treadmill mounted onto a 6°-of-freedom motion platform in combination with a virtual environment.

Participants

Transtibial amputees (n=10) and able-bodied controls (n=9).

Interventions

Mediolateral (ML) translations of the walking surface were imposed to manipulate gait stability. To provoke an adaptive gait pattern, a gait adaptability task was used in which subjects had to hit virtual targets with markers guided by their knees.

Main Outcome Measures

Walking speed, step length, step frequency, step width, and selected measures of gait stability (short-term Lyapunov exponents and backward and ML margins of stability [MoS]).

Results

Amputees walked slower than able-bodied people, with a lower step frequency and wider steps. This resulted in a larger ML MoS but a smaller backward MoS for amputees. In response to the balance perturbation, both groups decreased step length and increased step frequency and step width. Walking speed did not change significantly in response to the perturbation. These adaptations induced an increase in ML and backward MoS. To perform the gait adaptability task, both groups decreased step length and increased step width, but did not change step frequency and walking speed. ML and backward MoS were maintained in both groups.

Conclusions

Transtibial amputees have the capacity to use the same strategies to deal with challenges of gait stability and adaptability, to the same extent as able-bodied people.     

Effect of Different Walking Aids on Walking Capacity of Patients With Poststroke Hemiparesis

Allet L, Leemann B, Guyen E, Murphy L, Monnin D, Herrmann FR, Schnider A. Effect of different walking aids on walking capacity of patients with poststroke hemiparesis.

Objective

To examine the effects of 3 different walking aids on walking capacity, temporo-spatial gait parameters, and patient satisfaction.

Design

Observational study.

Setting

University Hospital of Geneva.

Participants

Hemiparetic inpatients (N=25) with impaired gait, at an early stage of rehabilitation, unfamiliar with any of the walking aids tested.

Interventions

On 3 consecutive days subjects used, in random order, 1 of 3 walking aids: 4-point cane, simple cane with ergonomic handgrip, and Nordic stick.

Main Outcome Measures

Maximal walking distance in 6 minutes, temporo-spatial gait parameters determined with a commercial electronic gait analysis system, and patients' preference on a subjective ranking scale.

Results

Walking distance was greatest with the simple cane with an ergonomic handgrip, followed by the 4-point cane and the Nordic walking stick. Walking velocity was highest with the simple cane, which was also indicated as the preferred walking aid by the patients. There was no significant difference in step length symmetry.

Conclusions

The simple cane with the ergonomic handgrip was not only preferred by patients, but was also the most efficient among 3 commonly used walking aids. It appears justified to take patients' subjective preference into account when prescribing a walking aid.     

Predicting Home and Community Walking Activity in People With Stroke

Fulk GD, Reynolds C, Mondal S, Deutsch JE. Predicting home and community walking activity in people with stroke.

Objective

To determine the ability of the 6-minute walk test (6MWT) and other commonly used clinical outcome measures to predict home and community walking activity in high-functioning people with stroke.

Design

Cross-sectional.

Setting

Outpatient physical therapy clinic.

Participants

Participants (N=32) with chronic stroke (n=19; >6mo poststroke) with self-selected gait speed (GS) faster than .40m/s and age-matched healthy participants (n=13).

Interventions

Not applicable.

Main Outcome Measures

Independent variables: 6MWT, self-selected GS, Berg Balance Scale (BBS), lower extremity motor section of the Fugl-Meyer Assessment, and Stroke Impact Scale. Dependent variable: average steps taken per day during a 7-day period, measured using an accelerometer.

Results

6MWT, self-selected GS, and BBS were moderately related to home and community walking activity. The 6MWT was the only predictor of average steps taken per day; it explained 46% of the variance in steps per day.

Conclusions

The 6MWT is a useful outcome measure in higher functioning people with stroke to guide intervention and assess community walking activity.     

Timed Walking Tests Correlate With Daily Step Activity In Persons With Stroke

Mudge S, Stott NS. Timed walking tests correlate with daily step activity in persons with stroke.

Objectives

To examine the relationship among 4 clinical measures of walking ability and the outputs of the StepWatch Activity Monitor in participants with stroke.

Design

Correlational study.

Setting

Clinic and participants' usual environments.

Participants

Fifty participants more than 6 months after stroke were recruited. All participants were able to walk independently, but with some residual difficulty.

Interventions

Not applicable.

Main Outcome Measures

Rivermead Mobility Index (RMI), Rivermead Motor Assessment (RMA), six-minute walk test (6MWT), ten-meter walk test (10MWT), StepWatch outputs (based on daily step counts and stepping rates).

Results

The correlations between the RMA and all StepWatch outputs were low (ρ=0.36-0.48; P<.05), as were most for the RMI (ρ=0.31-0.52; P<.05). The 10MWT and 6MWT had moderate to high correlations (ρ=0.51-0.73; P<.01) with most StepWatch outputs. Multiple regression showed that the 6MWT was the only significant predictor for most StepWatch outputs, accounting for between 38% and 54% of the variance. Age and the RMI were further significant predictors of 1 and 2 outputs, respectively.

Conclusions

The 6MWT has the strongest relationship with the StepWatch outputs and may be a better test than the 10MWT to predict usual walking performance. However, it should be remembered that the 6MWT explains only half the variability in usual walking performance. Thus, activity monitoring captures aspects of walking performance not captured by other clinical tests and should be considered as an additional outcome measure in stroke rehabilitation.     

Exploring Factors Associated With Long-Term Opioid Therapy in Cancer Survivors: An Integrative Review

ContextThe prevalence of chronic pain in cancer survivors is double that of the general U.S. population. Opioids have been the foundation of cancer pain management for decades; however, there is a paucity of literature on long-term opioid therapy (LTOT) in cancer survivors. An understanding of factors related to LTOT use in cancer survivors is needed to address chronic pain and balance opioid harms in the expanding population of cancer survivors.ObjectivesTo analyze the research of LTOT utilization and factors associated with persistent opioid use in cancer survivors.MethodsA five-stage integrative review process was adapted from Whittemore and Knafl. Data sources searched included Web of Science, PubMed, Embase, Cochrane, and Google Scholar. Quantitative research studies from 2010 to present related to cancer survivors managed on LTOT were included. Editorials, reviews, or abstracts were excluded.ResultsAfter reviewing 315 articles, 21 articles were included. We found that there were several definitions of LTOT in the reviewed studies, but the duration of opioid use (i.e., more than three months after completion of curative treatment) was the most common. The reviewed literature describes a relationship between LTOT and important biopsychosocial factors (cancer type, socioeconomic factors, and comorbidities).ConclusionThe studies in this review shed light on the factors associated with LTOT in cancer survivors. LTOT was common in certain populations of cancer survivors and those with a collection of patient-specific characteristics. This review suggests that there is a critical need for specialized research on chronic cancer pain and opioid safety in cancer survivors.     

Beyond Physical Capacity: Factors Associated With Real-world Walking Activity After Stroke

ObjectiveTo identify homogeneous subsets of survivors of chronic stroke who share similar characteristics across several domains and test if these groups differ in real-world walking activity. We hypothesized that variables representing the domains of walking ability, psychosocial, environment, and cognition would be important contributors in differentiating real-world walking activity in survivors of chronic stroke.DesignCross-sectional, secondary data analysis.SettingUniversity/laboratory.ParticipantsA total of 283 individuals with chronic (≥6mo) stroke (N=238).InterventionsNot applicable.Main Outcome MeasuresThirteen variables representing 5 domains were included: (1) walking ability: 6-minute walk test (6MWT), self-selected speed (SSS) of gait; (2) psychosocial: Patient Health Questionnaire-9, Activities-specific Balance Confidence (ABC) scale; (3) physical health: low-density lipoprotein cholesterol, body mass index, Charlson Comorbidity Index (CCI); (4) cognition: Montreal Cognitive Assessment (MoCA); and (5) environment: living situation and marital status, work status, Area Deprivation Index (ADI), Walk Score. Mixture modeling was used to identify latent classes of survivors of stroke. After identifying the latent classes, walking activity, measured as steps per day (SPD), was included as a distal outcome to understand if classes were meaningfully different in their real-world walkingResultsA model with 3 latent classes was selected. The 6MWT, SSS, ABC scale, and Walk Score were significantly different among all 3 classes. Differences were also seen for the MoCA, ADI, and CCI between 2 of the 3 classes. Importantly, the distal outcome of SPD was significantly different in all classes, indicating that real-world walking activity differs among the groups identified by the mixture model.ConclusionsSurvivors of stroke with lower walking ability, lower self-efficacy, lower cognitive abilities, and greater area deprivation had lower SPD. These results demonstrate that the physical and social environment (including socioeconomic factors) and cognitive function should also be considered when developing interventions to improve real-world walking activity after stroke.     

Examination of Sustained Gait Speed During Extended Walking in Individuals With Chronic Stroke

Objectives

To determine if individuals with chronic stroke were able to sustain their peak gait speed during the 6-minute walk test (6MWT), and to explore this sustainability across community ambulation potential subgroups.

Design

Prospective cross-sectional study.

Setting

University-based research laboratory, hospitals, and stroke support groups.

Participants

A sample of individuals with chronic stroke (N=48) completed a series of questionnaires and physical outcome measures, including gait mat assessment, during a single visit.

Interventions

Not applicable; 1-time cross-sectional data collection.

Main Outcome Measures

During the 6MWT, we measured peak gait speed and end gait speed to assess sustainability, along with beginning gait speed, total distance walked, and rating of perceived exertion. We also assessed maximum gait speed during the 10-meter walk test (10MWT). Finally, we examined these gait outcomes across the subgroups.

Results

During the 6MWT, peak gait speed declined from .89m/s (SD=.38) to an end speed of .82m/s (SD=.36), whereas perceived exertion increased from 7.7 (SD=2.6) to 11.8 (SD=3.6). This peak gait speed was slower than the 10MWT maximum speed of 1.06m/s (SD=.51), but faster than the 6MWT beginning speed of .81m/s (SD=.34). The unlimited community ambulator subgroup was the primary contributor to sustainability differences.

Conclusions

Predicting community ambulation potential based on the discrete gait speed from the 10MWT and endurance based on the average from the 6MWT might be incomplete if gait speed sustainability is not also assessed.     

Reliability of Ambulatory Walking Activity in Patients With Hematologic Malignancies

Knols RH, de Bruin ED, Aufdemkampe G, Uebelhart D, Aaronson NK. Reliability of ambulatory walking activity in patients with hematologic malignancies.

Objectives

To determine the relative and absolute reliability of the assessment of ambulatory walking activity during 2 consecutive weeks in patients with hematologic malignancies recovering at home from their medical treatment and to compare the physical activity level of hematologic cancer patients after high-dose chemotherapy with healthy subjects.

Design

Test-retest study of 2 consecutive 7-day recordings using the microprocessor-based step accelerometer 3 (SAM3).

Setting

Home and community.

Participants

Patients (n=23) with hematologic malignancies recovering from high-dose chemotherapy and healthy controls (n=30).

Interventions

Not applicable.

Main Outcome Measures

The intraclass correlation coefficient (ICC_3,1) and its 95% confidence interval (CI), SE of measurement procedure and its 95% CI, the smallest detectable difference (SDD), the coefficient of variation (CV), and t tests for the variables total steps and peak activity.

Results

The day-to-day and week-to-week CVs for walking activity and peak activity were 35.17% and 13.17% and 18.61% and 6.90%, respectively. For relative reliability, the ICCs for 2 consecutive 7-day recordings including the 95% CI for total steps and peak activity were 0.90 (95% CI, 0.75-0.98) and 0.85 (95% CI, 0.66-0.94), respectively. The absolute reliability for total steps and peak activity including the SE of measurement procedure and the 95% CI were 564 (95% CI, ±1106) and 2.42 steps (95% CI, ±4.74), respectively, for 2 consecutive 7-day recordings. The week-to-week SDD was 1564 for total steps and 6.70 for peak activity. The 7-day mean for total step activity was 5355 for the patients with hematologic malignancies and 6364 for healthy subjects (P<0.05).

Conclusions

The results of this study indicate that there is good relative reliability for the assessment of 2 consecutive 7-day recordings of ambulatory walking activity, and it showed that the SDD derived from this sample may be useful in detecting changes in daily walking activity in hematologic cancer patients who are recovering from intensive medical treatment. The study also documented compromised levels of ambulatory walking activity among hematologic cancer patients recovering from high-dose chemotherapy as compared with healthy controls.     

Factors Associated With Worsened or Improved Mental Health in the Great East Japan Earthquake Survivors

Objective

The aim of this study was to identify factors contributing to the worsening or improved mental health of long-term evacuees over three years following the Great East Japan Earthquake.

Anxiety and Depression Associated With Caregiver Burden in Caregivers of Stroke Survivors With Spasticity

Objective

To investigate the relationship between anxiety/depression and caregiver burden in informal caregivers of stroke survivors with spasticity.

Design

Data were collected via online surveys from informal caregivers 18 years or older who cared for stroke survivors.

Setting

Internet-based survey.

Participants

2007 through 2009 U.S. National Health and Wellness Survey database or Lightspeed Research general panel respondents (N=153).

Interventions

Not applicable.

Main Outcome Measures

Anxiety and depression were self-reported by the caregiver as a physician diagnosis. Depression severity was measured by the Patient Health Questionnaire-9 (PHQ-9). Caregiver burden was measured by the Oberst Caregiving Burden Scale (OCBS) and the Bakas Caregiving Outcomes Scale (BCOS). Logistic regression analyses were conducted with anxiety, depression, and the PHQ-9 depression severity categories as a result of each caregiver burden scale.

Results

Data were analyzed for 153 informal caregivers; they were mostly women (70.6%) and white (78.4%), with a mean age of 51.6 years. For every 1-point increase in the OCBS Difficulty Scale, the odds of anxiety or depression were 2.57 times as great (P<.001) and 1.88 times as great (P=.007), respectively. The odds of PHQ-9 severe depression versus all other categories combined were 2.48 times as great (P<.001). For every 1-point decrease in the BCOS, the odds of anxiety or depression were 2.43 times as great (P<.001) and 2.27 times as great (P=.002), respectively. The odds of PHQ-9 severe depression versus all other categories combined were 4.55 times as great (P<.001).

Conclusions

As caregiver burden increases, caregivers are more likely to have anxiety and depression. Depression severity also increases. Providing treatment to stroke survivors with spasticity that lessens the time and more importantly, the difficulty of caregiving may lead to a reduction in caregiver anxiety and depression.     

Rest-Activity Rhythm Characteristics Associated With Depression Symptoms in Stroke Survivors

ObjectiveTo examine which 24-hour rest-activity rhythm (RAR) characteristics are associated with depression symptoms in stroke survivors.DesignCross-sectional observational study examining associations of RAR characteristics with the presence of depression symptoms adjusting for age, sex, race, and medical comorbidity.SettingCommunity setting.ParticipantsStroke survivors: (1) recruited locally (N women=35, N men=28) and (2) a nationally representative probability sample (the National Health and Nutrition Examination Survey [NHANES]; N women=156, N men=124).InterventionsNone.MeasurementsObjective RAR characteristics derived from accelerometer recordings including activity onset/offset times and non-parametric measures of RAR strength (relative amplitude), stability (interdaily stability), and fragmentation (intradaily variability). The presence of depression symptoms was categorized using Patient Health Questionnaire scores.ResultsIn both samples, the only RAR characteristic associated with depression symptoms was intradaily variability (fragmentation): local sample, odds ratio=1.96 [95% confidence interval=1.05-3.63]; NHANES sample, odds ratio=1.34, [95% confidence interval=1.01-1.78]). In the NHANES sample, which included both mild and moderate/severe depression, the association between 24-hour sleep-wake fragmentation and depression symptoms was driven by moderate-to-severe cases.ConclusionsStroke survivors with higher levels of RAR fragmentation were more likely to have depression symptoms in both samples. These findings have implications, given prior studies in general samples linking RAR fragmentation with future depression and dementia risk. Research is needed to establish the potential consequences, mechanisms, and modifiability of RAR fragmentation in stroke survivors.     

Relation Between Aerobic Capacity and Walking Ability in Older Adults With a Lower-Limb Amputation

Objectives

To determine the relative aerobic load, walking speed, and walking economy of older adults with a lower-limb prosthesis, and to predict the effect of an increased aerobic capacity on their walking ability.

Design

Cross-sectional.

Setting

Human motion laboratory at a rehabilitation center.

Participants

Convenience sample of older adults (n=36) who underwent lower-limb amputation because of vascular deficiency or trauma and able-bodied controls (n=21).

Interventions

Not applicable.

Main Outcome Measures

Peak aerobic capacity and oxygen consumption while walking were determined. The relative aerobic load and walking economy were assessed as a function of walking speed, and a data-based model was constructed to predict the effect of an increased aerobic capacity on walking ability.

Results

People with a vascular amputation walked at a substantially higher (45.2%) relative aerobic load than people with an amputation because of trauma. The preferred walking speed in both groups of amputees was slower than that of able-bodied controls and below their most economical walking speed. We predicted that a 10% increase in peak aerobic capacity could potentially result in a reduction in the relative aerobic load of 9.1%, an increase in walking speed of 17.3% and 13.9%, and an improvement in the walking economy of 6.8% and 2.9%, for people after a vascular or traumatic amputation, respectively.

Conclusions

Current findings corroborate the notion that, especially in people with a vascular amputation, the peak aerobic capacity is an important determinant for walking ability. The data provide quantitative predictions on the effect of aerobic training; however, future research is needed to experimentally confirm these predictions.     

Factors Associated With Self-Concept in Children With Asthma

PURPOSE: To investigate the relationship of demographic asthma, family, and child factors with self-concept in children with asthma. METHODS: Data were collected twice approximately 4 years apart from both the affected children and their mothers (N = 134) via interviews and self-report questionnaire. FINDINGS: Children who demonstrated more negative attitudes toward their illness, had less satisfaction with family relationships, and used more negative coping behaviors had the poorest self-concepts. Over time, the greatest improvement in self-concept occurred in children whose attitudes and satisfaction with family relationships improved and whose use of negative coping behaviors decreased. CONCLUSIONS: Results suggest that some children with asthma, especially girls with severe asthma, appear to be at risk for poor self-concept.     

Postural Response Latencies Are Related to Balance Control During Standing and Walking in Patients With Multiple Sclerosis

Objective

To understand and examine the relation between postural response latencies obtained during postural perturbations and representative measures of balance during standing (sway variables) and walking (trunk motion).

Design

Cross-sectional.

Setting

University medical center.

Participants

Persons with multiple sclerosis (MS) (n=40) were compared with similar aged control subjects (n=20). There were 20 subjects with MS in the normal walking velocity group and 20 subjects with MS who had slow walking velocity based on a timed 25-foot walk (T25FW) of <5 seconds.

Interventions

None.

Main Outcome Measures

Postural response latency, sway variables, trunk motion variables.

Results

We found that subjects with MS with both slow or normal walking velocities had significantly longer postural response latencies than the healthy control group. Postural response latency was not correlated with the T25FW. Postural response latency was significantly correlated with center of pressure sway variables during quiet standing (root mean square: ρ=.334, P=.04; range: ρ=.385, P=.017; mean velocity: ρ=.337, P=.038; total sway area: ρ=.393, P=.015). Postural response latency was also significantly correlated with motion of the trunk during walking (sagittal plane range of motion: ρ=.316, P=.05; SD of transverse plane range of motion: ρ=−.43, P=.006).

Conclusions

These findings clearly indicate that slow postural responses to external perturbations in patients with MS contribute to disturbances in balance control during both standing and walking.     

Plantarflexor Weakness Negatively Impacts Walking in Persons With Multiple Sclerosis More Than Plantarflexor Spasticity

Objectives

To determine whether plantarflexor (PF) spasticity or ankle strength best predicts variance in walking capacity or self-perceived limitations in walking in persons with multiple sclerosis (MS) and whether persons with MS with PF spasticity are weaker and have greater walking dysfunction than do persons with MS without PF spasticity.

Design

Cross-sectional study.

Setting

University research laboratory.

Participants

Forty-two adults with MS (mean age, 42.9±10.1y; Expanded Disability Status Scale score, median=3.0, range=0–6) and 14 adults without disability (mean age, 41.9±10.1y).

Intervention

Not applicable.

Main Outcome Measures

PF spasticity and dorsiflexion and PF maximum voluntary isometric torque were assessed using the modified Ashworth Scale and a computerized dynamometer, respectively. The Timed 25-Foot Walk Test was the primary outcome measure of walking capacity. Secondary measures included the 6-Minute Walk Test and the 12-item Multiple Sclerosis Walking Scale.

Results

PF strength was the most consistent predictor of variance in walking capacity (Timed 25-Foot Walk Test: R² change=.23–.29, P≤.001; 6-Minute Walk Test: R² change=.12–.29, P≤.012), and self-perceived limitations of walking (12-item Multiple Sclerosis Walking Scale: R² change=.04–.14, P<.18). There were no significant differences (P>.05) between persons with MS with PF spasticity and persons with MS without PF spasticity for any of the outcome measures.

Conclusions

Our study suggests a unique contribution of PF weakness to walking dysfunction in persons with MS, and highlights the importance of evaluating PF strength in this clinical population.     

Factors Associated With Parental Distress

PROBLEM:  Associations of perceptions of social support, personal control, and child behavioral problems to distress in parents of children with mental health problems were examined.
METHODS:  One hundred and fifty-five parents of children 2–19 years old receiving community mental health services participated.
FINDINGS:  Stepwise regression analysis identified internalizing and externalizing child behaviors, perceived personal control, and tangible social support as independent predictors of parental distress. Independent predictors of objective distress included internalizing child behaviors, perceived personal control, and intangible social support.
CONCLUSIONS:  Internalizing and externalizing child behaviors were significantly associated with parental distress. Perceived personal control moderated the relationship between internalizing child behaviors and parental subjective distress.     

Increased Cardiovascular Disease Mortality Associated With Excessive Exercise in Heart Attack Survivors

ObjectiveTo test whether greater exercise is associated with progressively lower mortality after a cardiac event.Patients and MethodsWe used Cox proportional hazard analyses to examine mortality vs estimated energy expended by running or walking measured as metabolic equivalents (3.5 mL O₂/kg per min per day or metabolic equivalent of task-h/d [MET-h/d]) in 2377 self-identified heart attack survivors, where 1 MET-h/d is the energy equivalent of running 1 km/d. Mortality surveillance via the National Death Index included January 1991 through December 2008.ResultsA total of 526 deaths occurred during an average prospective follow-up of 10.4 years, 376 (71.5%) of which were related to cardiovascular disease (CVD) (International Statistical Classification of Diseases, 10th Revision codes I00-I99). CVD-related mortality compared with the lowest exercise group decreased by 21% for 1.07 to 1.8 MET-h/d of running or walking (P=.11), 24% for 1.8 to 3.6 MET-h/d (P=.04), 50% for 3.6 to 5.4 MET-h/d (P=.001), and 63% for 5.4 to 7.2 MET-h/d (P<.001) but decreased only 12% for ≥7.2 MET-h/d (P=.68). These data represent a 15% average risk reduction per MET-h/d for CVD-related mortality through 7.2 MET-h/d (P<.001) and a 2.6-fold risk increase above 7.2 MET-h/d (P=.009). Relative to the risk reduction at 7.2 MET-h/d, the risk for ≥7.2 MET-h/d increased 3.2-fold (P=.006) for all ischemic heart disease (IHD)–related mortalities but was not significantly increased for non–IHD-CVD, arrhythmia-related CVD, or non–CVD-related mortalities.ConclusionRunning or walking decreases CVD mortality risk progressively at most levels of exercise in patients after a cardiac event, but the benefit of exercise on CVD mortality and IHD deaths is attenuated at the highest levels of exercise (running: above 7.1 km/d or walking briskly: 10.7 km/d).