Walking Intensity Research Articles

Validation of the OMNI RPE Seven Day Exertional Recall Questionnaire

Purpose: The present study examined the validity of the Seven Day Recall Questionnaire among recreationally active men and women. Method: Initially, participants completed a level walk (2.5 mph [4.0 kph]), hill walk (3.5 mph [5.6 kph], 5% grade), and run (5.0 mph [8.0 kph], 2.5% grade). Seven days later, participants were given the Seven Day Recall Questionnaire and rated their perceived exertion associated with the exercise bouts. Participants then repeated the same exercise bouts as in Session 1, and the OMNI rating of perceived exertion (RPE) was estimated. Results: Concurrent validity indicated that for both men and women, respectively, the RPE-Overall (r = .48, r = .70), RPE-Leg (r = .43, r = .66), and RPE-Chest (r = .47, r = .66) derived from the Seven Day Recall Questionnaire distributed as a function of oxygen consumption. RPE-Overall (r = .61, r = .76), RPE-Leg (r = .56, r = .72), and RPE-Chest (r = .61, r = .72) from the Seven Day Recall Questionnaire distributed as a function of heart rate. Convergent validity coefficients between the perceptual responses from the Seven Day Recall Questionnaire and the recall/criterion session were: level walk (r = .53–.87, r = .51–.80), hill walk (r = .65–.79, r = .56–.64), and run (r = .60–.68, r = .68–.78) for men and women, respectively. Conclusions: Concurrent and convergent evidence partially supports the utilization of the Seven Day Recall Questionnaire to recall the relative intensity of walking and running exercise sessions conducted 7 days prior.

Do mass media campaigns improve physical activity? a systematic review and meta-analysis

BackgroundMass media campaigns are frequently used to influence the health behaviors of various populations. There are currently no quantitative meta-analyses of the effect of mass media campaigns on physical activity in adults.MethodsWe searched six electronic databases from their inception to August 2012 and selected prospective studies that evaluated the effect of mass media campaigns on physical activity in adults. We excluded studies that did not have a proper control group or did not report the uncertainties of the effect estimates. Two reviewers independently screened the title/abstracts and full articles. We used random-effects models to pool effect estimates across studies for 3 selected outcomes.ResultsNine prospective cohorts and before-after studies that followed-up 27,601 people over 8 weeks to 3 years met the inclusion criteria. Based on the pooled results from these studies, mass media campaigns had a significant effect on promoting moderate intensity walking (pooled relative risk (RR) from 3 studies=1.53, 95% Confidence Interval: 1.25 to 1.87), but did not help participants achieve sufficient levels of physical activity [4 studies pooled RR=1.02, 95% CI: 0.91 to 1.14)]. The apparent effect of media campaigns on reducing sedentary behavior (pooled RR=1.15, 95% CI: 1.03 to 1.30) was lost when a relatively low-quality study with large effects was excluded in a sensitivity analysis. In subgroup analyses, campaigns that promoted physical activity as a ‘social norm’ seemed to be more effective in reducing sedentary behavior.ConclusionMass media campaigns may promote walking but may not reduce sedentary behavior or lead to achieving recommended levels of overall physical activity. Further research is warranted on different campaign types and in low- and middle- income countries.

Oxygen cost of walking, physical activity, and sedentary behaviours in rheumatoid arthritis

Objectives: To evaluate the oxygen cost of gait and measure physical activity profiles, including time spent sedentary, in people with rheumatoid arthritis (RA) and matched controls.Method: We recruited 19 people with RA and 19 controls matched for age, sex, and body mass index (BMI). Demographic details and clinical characteristics of the RA population were recorded. Oxygen uptake per metre walked (oxygen cost) was measured in the laboratory using a portable gas analyser. Activity profiles including the number of steps per day, time spent sedentary (sitting or lying down), and intensity of walking were recorded over 5 days using an activity monitor, from which physical activity was classified by intensity categories. Levels of pain, fatigue, anxiety, and depression were recorded.Results: People with RA walked with a slower self-selected gait speed (p < 0.001) than controls but there was no difference in the oxygen cost of walking (p = 0.992) between the groups. People with RA took fewer steps (p < 0.001), had increased sedentary time (p = 0.029) and lower time walking at cadences commensurate with moderate to vigorous physical activity (MVPA) compared to controls (p < 0.001). Pain, fatigue, and depression were higher in the RA group (all p < 0.001).Conclusions: The oxygen cost of walking in this cohort of people with RA was similar to that of matched controls but there was an increase in time spent sedentary and a reduction in time spent at cadences commensurate with MVPA. Clinical symptoms such as depression, pain, and fatigue may explain the changes in activity/sedentary behaviours in people with RA and require further investigation.

Intensity of daily physical activity is associated with central hemodynamic and leg muscle oxygen availability in COPD

In chronic obstructive pulmonary disease (COPD), daily physical activity is reported to be adversely associated with the magnitude of exercise-induced dynamic hyperinflation and peripheral muscle weakness. There is limited evidence whether central hemodynamic, oxygen transport, and peripheral muscle oxygenation capacities also contribute to reduced daily physical activity. Nineteen patients with COPD (FEV1, 48 ± 14% predicted) underwent a treadmill walking test at a speed corresponding to the individual patient's mean walking intensity, captured by a triaxial accelerometer during a preceding 7-day period. During the indoor treadmill test, the individual patient mean walking intensity (range, 1.5 to 2.3 m/s2) was significantly correlated with changes from baseline in cardiac output recorded by impedance cardiography (range, 1.2 to 4.2 L/min; r = 0.73), systemic vascular conductance (range, 7.9 to 33.7 ml·min(-1)·mmHg(-1); r = 0.77), systemic oxygen delivery estimated from cardiac output and arterial pulse-oxymetry saturation (range, 0.15 to 0.99 L/min; r = 0.70), arterio-venous oxygen content difference calculated from oxygen uptake and cardiac output (range, 3.7 to 11.8 mlO2/100 ml; r = -0.73), and quadriceps muscle fractional oxygen saturation assessed by near-infrared spectrometry (range, -6 to 23%; r = 0.77). In addition, mean walking intensity significantly correlated with the quadriceps muscle force adjusted for body weight (range, 0.28 to 0.60; r = 0.74) and the ratio of minute ventilation over maximal voluntary ventilation (range, 38 to 89%, r = -0.58). In COPD, in addition to ventilatory limitations and peripheral muscle weakness, intensity of daily physical activity is associated with both central hemodynamic and peripheral muscle oxygenation capacities regulating the adequacy of matching peripheral muscle oxygen availability by systemic oxygen transport.

Indoor and Outdoor Mobility following Total Knee Arthroplasty

To determine the relationship between indoor and outdoor mobility capacity in older adults with unilateral total knee arthroplasty (TKA) and, secondarily, to determine walking intensity in the same population and to compare all outcomes to a control group of older adults without knee pathology. In this cross-sectional study, participants (TKA=16, mean 22.9 (SD 9.7) mo post TKA; control=22) completed indoor walking tests and a 580 m outdoor course that included varying terrain (e.g., curbs, grass, sidewalk) and frequent changes in direction. Walking capacity was assessed using stopwatches, global positioning system watches and accelerometers. Outdoor walking time was moderately correlated (p<0.05) with the timed up-and-go (TUG) test (r=0.65), stair-climb test (SCT) (r=0.67 ascending, r=0.79 descending), 10m walk test (10 mWT) (r=0.73), and 6-minute walk test (6 MWT) (r=-0.75). Based on activity counts, walking intensity levels for participants in both groups were moderate (outdoor walk and 6 MWT). There was no significant difference in walking capacity between groups (TUG, SCT, 10 mWT, 6 MWT, outdoor walk). Common clinical walking tests are moderately correlated with outdoor mobility. Mobility capacity of individuals post TKA was similar to controls in both indoor and outdoor environments, and participants in both groups achieved moderate physical activity levels with walking.

Stride Rate and Walking Intensity in Healthy Older Adults

The study investigated (a) walking intensity (stride rate and energy expenditure) under three speed instructions; (b) associations between stride rate, age, height, and walking intensity; and (c) synchronization between stride rate and music tempo during overground walking in a population of healthy older adults. Twenty-nine participants completed 3 treadmill-walking trials and 3 overground-walking trials at 3 self-selected speeds. Treadmill VO2 was measured using indirect calorimetry. Stride rate and music tempo were recorded during overground-walking trials. Mean stride rate exceeded minimum thresholds for moderate to vigorous physical activity (MVPA) under slow (111.41 ± 11.93), medium (118.17 ± 11.43), and fast (123.79 ± 11.61) instructions. A multilevel model showed that stride rate, age, and height have a significant effect (p < .01) on walking intensity. Healthy older adults achieve MVPA with stride rates that fall below published minima for MVPA. Stride rate, age, and height are significant predictors of energy expenditure in this population. Music can be a useful way to guide walking cadence.

Prolonged sitting and markers of cardiometabolic disease risk in children and youth: A randomized crossover study

ObjectiveRecent evidence suggests that short bouts of uninterrupted sedentary behavior reduce insulin sensitivity and glucose tolerance while increasing triglyceride levels in both healthy and overweight/obese adults. To date no study has examined the acute impact of uninterrupted sitting in children and youth. The objective of the present study was to determine whether 8h of uninterrupted sitting increases markers of cardiometabolic disease risk in healthy children and youth, in comparison to 8h of sitting interrupted by light intensity walk breaks or structured physical activity. Materials/Methods11 healthy males and 8 healthy females between the ages of 10 and 14years experienced 3 conditions in random order: (1) 8h of uninterrupted sitting (Sedentary); (2) 8h of sitting interrupted with a 2-min light-intensity walk break every 20min (Breaks); and (3) 8h of sitting interrupted with a 2-min light-intensity walk break every 20min as well as 2×20min of moderate-intensity physical activity (Breaks+Physical Activity). Insulin, glucose, triglyceride, HDL and LDL cholesterol area under the curve were calculated for each condition. ResultsWe observed no significant differences in the area under the curve for any marker of cardiometabolic disease risk across the 3 study conditions (all p>0.09). ConclusionsThese results suggest that in comparison to interrupted sitting or structured physical activity, a single bout of 8h of uninterrupted sitting does not result in measurable changes in circulating levels of insulin, glucose, or lipids in healthy children and youth.

Reduced Incidence of Cardiac Arrhythmias in Walkers and Runners

PurposeWalking is purported to reduce the risk of atrial fibrillation by 48%, whereas jogging is purported to increase its risk by 53%, suggesting a strong anti-arrhythmic benefit of walking over running. The purpose of these analyses is to compare incident self-reported physician-diagnosed cardiac arrhythmia to baseline energy expenditure (metabolic equivalent hours per day, METhr/d) from walking, running and other exercise.MethodsProportional hazards analysis of 14,734 walkers and 32,073 runners.ResultsThere were 1,060 incident cardiac arrhythmias (412 walkers, 648 runners) during 6.2 years of follow-up. The risk for incident cardiac arrhythmias declined 4.4% per baseline METhr/d walked by the walkers, or running in the runners (P = 0.0001). Specifically, the risk declined 14.2% (hazard ratio: 0.858) for 1.8 to 3.6 METhr/d, 26.5% for 3.6 to 5.4 METhr/d, and 31.7% for ≥5.4 METhr/d, relative to <1.8 METhr/d. The risk reduction per METhr/d was significantly greater for walking than running (P<0.01), but only because walkers were at 34% greater risk than runners who fell below contemporary physical activity guideline recommendations; otherwise the walkers and runners had similar risks for cardiac arrhythmias. Cardiac arrhythmias were unrelated to walking and running intensity, and unrelated to marathon participation and performance.ConclusionsThe risk for cardiac arrhythmias was similar in walkers and runners who expended comparable METhr/d during structured exercise. We found no significant risk increase for self-reported cardiac arrhythmias associated with running distance, exercise intensity, or marathon participation. Rhythm abnormalities were based on self-report, precluding definitive categorization of the nature of the rhythm disturbance. However, even if the runners’ arrhythmias include sinus bradycardia due to running itself, there was no increase in arrhythmias with greater running distance.

Effects of Aerobic Exercise on Body Composition and Muscle Strength in Over-Weight to Obese Old Women with Intellectual Disability: A Pilot Study

Aim: To examine the effect of treadmill walking on over-weight to obese females with unspecified mild ID (intellectual disability). Method: Randomized assignment to an aerobic exercise group (G1, n = 6) and control group (G2, n = 3). The G1 performed mild to moderate intensity walking for 25-45 minutes per exercise session, 3-5 times per week up to a weekly walking of 150 minutes, for 32 consecutive weeks. The G2 maintained routine daily activities. Results: The mean age of the study subjects was 57.2 ±7.5 year, BMI was significantly decreased at the conclusion of the intervention (P = 0.005). In the G1, the subcutaneous fat area was also significantly decreased (P = 0.005) but not in G2. No change was there in the visceral fat area of both groups. The quadriceps muscle maximal isometric muscle strength of the G1 and G2 did not change. Conclusion: Long term mild to moderate intensity of aerobic physical exercise for over-weight to obese women with ID is a feasible and effective plan in reducing subcutaneous fat mass, while muscle strength remains unchanged.

Disentangling the effects of choice and intensity on affective response to and preference for self-selected- versus imposed-intensity physical activity

ObjectiveTo examine the independent effects of physical activity (PA) intensity and choice of PA intensity when comparing affective response to and relative preference for self-selected-intensity versus imposed higher intensity PA. DesignWithin-subjects experiment. MethodsTwenty-nine healthy, low-active women completed four PA bouts over two sessions. The first session consisted of a one-third mile self-selected-intensity treadmill walk during which the speed was recorded, but was not visible to the participants. The second session consisted of three, counterbalanced, one-third mile treadmill conditions: (a) self-selected intensity, (b) same intensity as recorded for the first-session-self-selected-intensity walk, but with the intensity imposed by the experimenter (i.e., yoked-self-selected intensity), and (c) intensity set at 20% higher than the first-session-self-selected-intensity walk (imposed higher intensity). Acute affective valence (pleasure/displeasure) was recorded prior to, during, and following each walking bout. Preference for each walking intensity was assessed using a behavioral-choice paradigm. ResultsContrary to hypotheses, there was no effect of condition on acute affective valence. However, consistent with hypotheses, there was a linear trend, F(1, 22) = 11.00, p = .003, indicating preference in descending order from self-selected-intensity to yoked-self-selected-intensity to imposed higher intensity PA. ConclusionsBoth choice over the intensity and a lower intensity per se contributed to greater preference for self-selected-intensity over imposed higher intensity PA among healthy low-active women; however, there was no evidence to support the notion that affective response to PA mediated this relationship.

Green Tea and Vitamin E Enhance Exercise-Induced Benefits in Body Composition, Glucose Homeostasis, and Antioxidant Status in Elderly Men and Women

Objective: To investigate the effects of green tea plus vitamin E in addition to exercise on body composition and metabolic and antioxidant parameters in healthy elderly individuals. Design: Interventional randomized controlled prospective trial. Methods: For 12 weeks, 22 elderly men and women (age: 71.1 ± 1.2 years; body mass index: 28.3 ± 0.5 kg/m2 [mean ± SE]) undertook 30 minutes of moderately intense walking 6 d/wk. They were randomly assigned to ingest either green tea plus vitamin E (GTVE; 3 cups and 400 IU, respectively; n = 11) or placebo (n = 11). Data on anthropometrics, fasting insulin and glucose levels, physical fitness, dietary intake, safety parameters, and biomarkers of oxidation status were recorded and analyzed at the start and end of the study. Results: Though dietary intake was unchanged, improved exercise capacity was followed by a significant reduction in body weight and fasting insulin levels in all participants. Additional consumption of GTVE resulted in a twofold increase in serum vitamin E (from 20.4 to 40.6 μmol/L, p < 0.001) and a decrease of men's and women's waist circumferences (from 100.8 and 95.7 to 96.9 and 85.0 cm, p < 0.05 and p < 0.01, respectively) and fasting glucose levels (from 5.30 to 4.98 mmol/L, p < 0.01). Plasma protein carbonyls dropped (from 0.93 to 0.77 nmol/mg protein, p < 0.05), whereas erythrocyte catalase activities increased (from 26.7 to 29.7 U/g hemoglobin, p < 0.05) in the GTVE group only. Oral peroxidase activities were increased in both groups. Conclusions: A daily dose of GTVE in healthy elderly men and women may improve exercise-induced benefits in body composition and glucose tolerance and may also lower oxidative burden.

Cadence, Energy Expenditure, and Gait Symmetry During Music-Prompted and Self-Regulated Walking in Adults With Unilateral Transtibial Amputation

Walking cadence has shown promise for estimating walking intensity in healthy adults. Auditory cues have been shown to improve gait symmetry in populations with movement disorders. We investigated the walking cadence-energy expenditure relationship in unilateral transtibial amputees (TTAs), and the potential of music cues for regulating walking cadence and improving gait symmetry. Seventeen unilateral TTAs performed 2 5-min treadmill walking trials, followed by 2 5-min overground walking trials (self-regulated "brisk" intensity, and while attempting to match a moderate-tempo digital music cue). Walking cadence significantly (P < .001) and accurately (R(2) = .55, SEE = 0.50 METs) predicted energy expenditure, and a cadence of 86 steps·min(-1) was equivalent to a 3-MET intensity. Although most participants were able to match cadence to prescribed music tempo, gait symmetry was not improved during the music-guided condition, compared with the self-regulated condition. This is the first study to investigate the utility of walking cadence for monitoring and regulating walking intensity in adults with lower limb prosthesis. Cadence has similar or superior accuracy as an indicator of walking intensity in this population, compared with the general population, and adults with a unilateral TTA are capable of walking at moderate intensity and above for meaningful bouts of time.

Effect of robotic gait training on cardiorespiratory system in incomplete spinal cord injury

The objectives in this study were to investigate the effect of robot-assisted gait training on cardiorespiratory fitness in subjects with motor incomplete spinal cord injury and document the exercise intensity of robotic walking in comparison with the recommended guidelines. Ten patients followed a 24-session training program with a robotic gait orthosis in addition to physiotherapy sessions completed within 10 to 16 wk. Cardiorespiratory fitness was determined in a graded arm crank exercise test before and after the training program. To assess the intensity of robot-assisted walking, oxygen consumption (VO2) and heart rate (HR) were measured during a training session early in and at the end of the training program, and exercise intensity measures (percentage of VO2 reserve [%VO2R], percentage of HR reserve [%HRR], and metabolic equivalents [METs]) were calculated. Whereas no changes were found in peak VO2, the resting and submaximal HR at a constant work load were significantly lower after training. Most subjects exercised at low intensity (<30%VO2R, <30%HRR, <3.0 METs), and only two subjects exercised at moderate intensity (>3.0 METs). In spite of the low exercise intensity of the training program and no changes in peak VO2, robot-assisted gait training induced some improvement in cardiorespiratory fitness, as suggested by lower resting and submaximal HR values.

Physical activity and body mass index among women who have experienced infertility

IntroductionThe experience of infertility is a common medical condition in the developing countries. The aim of this retrospective epidemiologic study was to determine fertility status and parity in Babol, Iran and then identify physical activity and body mass index (BMI) among women who have experienced infertility.Material and methodsA total of 1,081 women aged 20-45 years were selected using cluster sampling. The current physical activity was measured using the original International Physical Activity Questionnaire short form. Lifestyle factors were compared between those who had experienced infertility (n = 168) and the rest of the women. A face-to-face household interview was conducted using a specially designed interview questionnaire.ResultsAfter adjusting for suspected confounding factors, women with infertility experience had a 4.8-fold increased risk of obesity (OR = 2.02, CI = 0.70, 5.84) and almost a 3.8-fold increased risk of being overweight (OR = 2.11, CI = 0.72, 6.17) compared to women without infertility. No significant differences were found in Met-minutes of sedentary activity, intensity of walking, moderate, vigorous, and total physical activity, self-reported dietary intake, exercise, and level of physical activity between women with and without experience of infertility.ConclusionsSince both obesity and infertility are increasing public health issues in Iranian women, more attention should be paid to lifestyle behaviors, especially gaining weight in women who have experienced infertility.

Physical activity, sedentary behavior and total wellness changes among sedentary adults: a 4-week randomized controlled trial

BackgroundThe construct of total wellness includes a holistic approach to the body, mind and spirit components of life. While the health benefits of reducing sedentary behavior and increasing physical activity are well documented, little is known about the influence on total wellness of an internet-based physical activity monitor designed to help people to achieve higher physical activity levels.PurposeThe purpose of this four-week, personal activity monitor-based intervention program was to reduce sedentary behavior and increase physical activity levels in daily living for sedentary adults and to determine if these changes would also be associated with improvement in total wellness.MethodsTwenty-two men and 11 women (27 years ± 4.0) were randomly assigned to either an intervention (n = 18) or control group (n = 15). The intervention group interacted with an online personal activity monitor (Gruve Solution™) designed to reduce sedentary time and increase physical activity during activities of daily living. The control group did not interact with the monitor, as they were asked to follow their normal daily physical activities and sedentary behavior routines. The Wellness Evaluation of Lifestyle (WEL) inventory was used to assess total wellness. Sedentary time, light, walking, moderate and vigorous intensity physical activities were assessed for both intervention and control groups at baseline and at week-4 by the 7-day Sedentary and Light Intensity Physical Activity Log (7-day SLIPA Log) and the International Physical Activity Questionnaire (IPAQ).ResultsSignificant increases in pre-post total wellness scores (from 64% ± 5.7 to 75% ± 8.5) (t (17) = -6.5, p < 0.001) were observed in the intervention group by the end of week four. Intervention participants decreased their sedentary time (21%, 2.3 hours/day) and increased their light (36.7%, 2.5 hours/day), walking (65%, 1057 MET-min/week), moderate (67%, 455 MET-min/week) and vigorous intensity (60%, 442 MET-min/week) physical activity (all p < 0.001). No significant differences for total wellness were observed between the groups at baseline and no pre-post significant differences were observed for any outcome variable in the control group.ConclusionTotal wellness is improved when sedentary, but sufficiently physically active adults, reduce sedentary time and increase physical activity levels (i.e. light, waking, moderate and vigorous).

Effects of Different Intensity Walking on Serum Nitric Oxide for the Elderly Men

Objective: In order to study the effect of different intensity exercise on serum nitric oxide and nitric oxide synthase of elderly men, and look for the most appropriate exercise intensity for them which can prevent cardiovascular disease. Methods: 36 men who are 55 to 62 years old, were randomly divided into the low intensity group(L group,n=12), the moderate-intensity group(M group,n=12) and the high-intensity group(H group,n=12). During the period for testing, they walked for 12 weeks, 4 times per week, 45 minutes for each time,target heart rate is 100 ~110 beats/min(L group), 110 ~120 beats/min(M group), 120~ 130 beats/min(H group). With an over-night fast, all the subject venous blood samples were drawn by 4ml before and after the exercise. The blood samples were centrifuged and separated immediately, then serum nitric oxide content, TNOS activity, cNOS activity, iNOS activity were measured.Results:In low-intensity group, serum NO content, TNOS activity, cNOS activity were significantly increased than pre-exercise (P&lt;0.05); in moderate-intensity group,serum NO content,TNOS activity,cNOS activity were very significantly increased than pre-exercise (P &lt;0.01);the indicators of high-intensity exercise group did not change significantly. Conclusion: we recommend that a more appropriate exercise intensity is 100-120 beats /min for elderly during fitness exercise, and especially 110-120 beats/min. Such intensity exercise can increase NO content in vivo, thus effectively prevent the occurrence of cardiovascular disease.

Cardiovascular Responses Associated with Daily Walking in Subacute Stroke

Despite the importance of regaining independent ambulation after stroke, the amount of daily walking completed during in-patient rehabilitation is low. The purpose of this study is to determine if (1) walking-related heart rate responses reached the minimum intensity necessary for therapeutic aerobic exercise (40%–60% heart rate reserve) or (2) heart rate responses during bouts of walking revealed excessive workload that may limit walking (>80% heart rate reserve). Eight individuals with subacute stroke attending in-patient rehabilitation were recruited. Participants wore heart rate monitors and accelerometers during a typical rehabilitation day. Walking-related changes in heart rate and walking bout duration were determined. Patients did not meet the minimum cumulative requirements of walking intensity (>40% heart rate reserve) and duration (>10 minutes continuously) necessary for cardiorespiratory benefit. Only one patient exceeded 80% heart rate reserve. The absence of significant increases in heart rate associated with walking reveals that patients chose to walk at speeds well below a level that has meaningful cardiorespiratory health benefits. Additionally, cardiorespiratory workload is unlikely to limit participation in walking. Measurement of heart rate and walking during in-patient rehabilitation may be a useful approach to encourage patients to increase the overall physical activity and to help facilitate recovery.

Step rate-determined walking intensity and walking recommendation in Chinese young adults: a cross-sectional study

There is lack of data on the physiological characteristics of over ground walking and walking recommendations for Chinese young adult. The purpose of the study was to measure walking-related energy...

Using a body-worm accelerometer to identify the start and end points of a stride during walking

Introduction: Many body-worn accelerometers provide an accurate measure for number of steps during walking, however the start and end point of those steps is often not reported, meaning the individual step duration cannot be determined. There has been recent interest in using cadence for measurement of walking intensity in large datasets. However, calculating an accurate value for cadence requires that the duration of walking is known as well as the number of steps taken and when a bout starts and ends. This study aimed to develop and validate an algorithm to identify the start and end points of a stride from the acceleration output of a body-worn sensor.

Autonomic regulation, physical activity and perceived stress in subjects with musculoskeletal pain: 24-hour ambulatory monitoring

The aim of the study was to investigate autonomic nervous system regulation, physical activity (PA) and perceived stress and energy during daily activities in subjects with chronic muscle pain in the neck–shoulders (trapezius myalgia) (n=23) and symptom-free controls (n=22). Subjects underwent 24-hour objective ambulatory monitoring of heart rate variability (HRV) and PA, and reported their perceived stress and energy in a diary. Standard HRV measures were extracted in time and frequency domains. The volume and pattern of different types of activities were quantified in terms of intensity and duration of walking, and time spent sitting, standing and lying during the 24-hour measurement. Results showed shortened inter-beat-intervals (higher heart rate) and reduced HRV in the pain group, most pronounced during sleep (p<0.05). For overall PA, the pain group showed increased lying time, compared to controls (p<0.05). A different activity pattern was found in the pain group, with reduced leisure time PA and increased PA during morning hours, in comparison with controls (p<0.05). Both groups demonstrated low levels of perceived stress, whereas reduced energy was observed in the pain group (p<0.05). In conclusion, monitoring of 24-hour HRV demonstrated diminished HRV among persons with chronic neck–shoulder pain. This reflected aberration in autonomic regulation, suggesting reduced parasympathetic activation and increased sympathetic tone as an element in maintenance of chronic muscle pain.