Peak Cadence Research Articles

EVALUATING THE RELATIONSHIP BETWEEN RADIOTHERAPY CLINICAL TARGET VOLUME AND GAIT ACTIVITY IN HIGH GRADE GLIOMA

Abstract AIMS Walking speed or peak cadence serves as a potential indicator of overall health, particularly in older individuals, with documented predictive value for various health-related outcomes. The emergence of wearable technology for gait analysis has facilitated early disease detection and monitoring in conditions like Parkinson’s disease. This study aimed to explore the association between gait metrics and radiotherapy Clinical Target Volume (CTV) in participants with High-Grade Glioma (HGG) enrolled in the BrainWear study, which captures longitudinal physical activity data through wearable devices. METHOD 21 HGG participants provided accelerometer data before and after a course of radiotherapy. Using Spearman rank correlation analysis, we examined the relationship between CTV and gait features while considering the total radiotherapy dose and tumour location. Participant data was cut at the same time point of 14-days either side of the start or end of radiotherapy to ensure the data was aligned. RESULTS The analysis revealed a moderately negative correlation between CTV and peak cadence at the onset of radiotherapy. At the end of radiotherapy and in the two weeks following completion, both peak cadence in 1 minute and 30 minutes showed a stronger inverse correlation with CTV (Spearman’s ρ = -0.52 and ρ = -0.44 respectively, p-value <0.05). This suggests that higher CTV may be associated with decreased peak cadence, particularly at the time of expected radiotherapy toxicity. Subgroup analysis focusing on patients with CTV covering the motor cortex further illustrated a more significant inverse correlation between CTV size and peak cadence (Spearman’s ρ = -0.77, p-value <0.05). CONCLUSION This study highlights the importance of understanding the interplay between tumour treatment volume, location and physical function. Further exploration of CTV volume in relation to anatomical areas such as the motor cortex could provide deeper insights into this relationship and provide opportunities for personalised monitoring in HGG.

Relationship between activity and sleep, as measured through a wearable accelerometer, and appropriate cardioverter defibrillator interventions: a prospective SafeHeart substudy.

Physical activity has shown association with ventricular arrhythmia, however, the role of specific behavioral patterns over a 24 h cycle remains unknown. Therefore, we aimed to explore associations between physical behavior and appropriate implantable cardioverter defibrillator (ICD) therapy. We included patients with an ICD at two European sites, who wore wrist-based accelerometers capturing 24 h movement and sleep behaviours for 28 days. Behavioural measures included activity volume, duration and intensity, sleep duration, and efficiency. Participants were followed for 12 months for the outcome of appropriate ICD therapy. Cox proportional hazard models with restricted cubic splines were used for the analysis. Lastly, the predictive capacity was tested. A total of 253 ICD patients were included (mean age 63.5 (±10.2), 48 (19.0%) female). During follow-up, 40 participants (15.8%) received appropriate ICD therapy; 32 anti-tachycardia pacing (ATP) only (12.6%), 5 shock only (2.0%), and 3 combined ATP and shock (1.2%). In the adjusted model, high inactive duration (HR 1.40 (95% 1.10-1.78)), peak walking cadence (HR 1.07 (95% 1.03-1.12)), and total sleep duration (HR 1.50 (1.02-2.22)) were associated with the outcome. The dose-response relationship was U-shaped for inactive duration with a cut-off at 16 h, and linear for peak cadence and sleep. The prediction model reached an area under the receiver operating characteristic curve of 0.70 ± 0.03, with highest accuracy in the first months. Wearable-derived 24 h movement and sleep behaviours collected over 28 days were associated with later appropriate ICD therapy risk. Testing of the predictive value of digital biomarkers for enhanced risk stratification of ventricular arrhythmia warrants larger prospective studies. National Trial Registration (NL9218, http://onderzoekmetmensen.nl/).

Impact of Stiffness of Quadriceps on the Pedaling Rate of Maximal Cycling.

to investigate the relationship between musculoarticular stiffness and pedaling rate. twenty-two healthy, untrained male volunteers (19 ± 2 years, 175 ± 6 cm, 74 ± 16 kg) were divided into two groups after their musculoarticular (MA) stiffness was tested, and these groups were the stiffness group (SG) and compliant group (CG). A 6-s maximal cycling test was conducted in four cycling modes, which were levels 5 and 10 air-resistance, and levels 3 and 7 magnetic-resistance. Peak and average cadence, peak power output (POpeak), crank force (CFpeak), peak rate of crank force development (RCFD), and the angle of peak crank force were collected. The significance of differences between the two groups for these variables was assessed using an independent samples t-test. Pearson product-moment correlations were calculated to analyze the relationship between MA stiffness and each performance variable. the SG had significantly higher peak cadence and average cadence at level 3 magnetic-resistance, peak crank force, and peak power output at level 10 air-resistance, peak rate of crank force development at levels 5 air-resistance, 10 air-resistance, and 3 magnetic-resistance (p < 0.05). MA stiffness was significantly correlated with average cadence at levels 5 and 10 air-resistance, peak crank force in all 4 modes, and RCFD and peak power output at level 10 air-resistance. There were no significant relationships between MA stiffness and the angle of peak crank force in each cycling mode. results indicate that participants with relatively higher MA stiffness seemed to have a higher pedaling rate during a 6-s sprint cycling in these conditions. They also performed a superior crank force and rate of crank force development, producing greater power output when sprint cycling. Optimizing cycling resistance or gear ratio to enhance both RCFD and musculotendinous stiffness may be crucial for improving sprint cycling performance.

Step cadence as a novel objective postoperative recovery metric in children who undergo laparoscopic appendectomy

Daily step counts from consumer wearable devices have been used to objectively assess postsurgical recovery in children. However, step cadence, defined as steps taken per minute, may be a more specific measure of physiologic status. The purpose of this study is to define objective normative physical activity recovery trajectories after laparoscopic appendectomy using this novel metric. We hypothesized that patients would have a progressive increase in peak cadence until reaching a plateau representing baseline status, and this would occur earlier for simple compared with complicated appendicitis. Children aged 3 to 18 years were enrolled after laparoscopic appendectomy for simple or complicated appendicitis between March 2019 and December 2022 at a tertiary children's hospital. Participants wore a Fitbit for 21 postoperative days. The peak 1-minute cadence and peak 30-minute cadence were determined each postoperative day. Piecewise linear regression was conducted to generate normative peak step cadence recovery trajectories for simple and complicated appendicitis. A total of 147 children met criteria (53.7% complicated appendicitis). Patients with simple appendicitis reached plateau postoperative day 10 at a mean peak 1-minute cadence of 111 steps/minute and a mean peak 30-minute cadence of 77 steps/minute. The complicated appendicitis recovery trajectory reached a plateau postoperative day 13 at a mean peak 1-minute cadence of 106 steps/minute and postoperative day 15 at a mean peak 30-minute cadence of 75 steps/minute. Using step cadence, we defined procedure-specific normative peak cadence recovery trajectories after laparoscopic appendectomy. This can empower clinicians to set data-driven expectations for recovery after surgery and establish the groundwork for consumer wearable devices as a post-discharge remote monitoring tool.

Visual Impairment and Real-World Home Physical Activity With Home Environment in an Older Population

Physical activity levels are lower in visual impairment. However, additional factors, such as home environmental features, which can modify physical activity in this group, are unknown. To investigate the association between home environment features and home physical activity in patients with visual impairment. This cross-sectional study of clinical patients included participants with glaucoma suspect and primary glaucoma who were 60 years or older with varying degrees of visual field damage. Study participants were recruited from the Johns Hopkins Wilmer Eye Institute Glaucoma Clinic, Baltimore, Maryland, from September 2013 through March 2015. Data were analyzed from December 19, 2022, through December 25, 2022. Total in-home steps taken per day was the primary outcome measure; time in daily home physical activity and nonsedentary activity were secondary outcomes. A total of 153 participants were included in analyses with mean age of 71 (SD, 7.8) years and 71 were female (46%). Sixty percent had more than 1 comorbid illness, about one-third took 5 or more prescription drugs, and median daily home steps were 1137. Median integrated visual field sensitivity was 28 dB. Better-eye median visual acuity in logMAR was 0.05 (20/22 Snellen equivalent). For every 0.1-log unit increment in average measured home lighting, participants took 5% more daily steps (rate ratio [RR], 1.05; 95% CI, 1.00-1.10; P = .04) and had a 3% faster average daily peak cadence (RR, 1.03; 95% CI, 1.01-1.05; P = .01). The average number of nonsedentary activity minutes (RR, 1.04; 95% CI, 1.00-1.07; P = .06), average bout duration (β = 0.03; 95% CI, 0.00-.07; P = .06), and activity fragmentation (β = -0.06; 95% CI, -0.13 to 0.00; P = .06) showed associations with home lighting. The number of hazards was not associated with any activity metric (steps: RR, 1.14; 95% CI, 0.96-1.34; P = .13; peak cadence: RR, 1.00; 95% CI, 0.93-1.08; P = .98; and nonsedentary time: RR, 1.11; 95% CI, 0.98-1.26; P = .11), nor was the frequency of hazards. In this study, results demonstrated that home environment features, particularly lighting, may influence home activity metrics in older adults with visual impairment. Further prospective studies would be needed to confirm if home modifications can improve at-home activity.

Free-Living Peak Cadence in Multiple Sclerosis: A New Measure of Real-World Walking?

Background Physical function and walking performance have become important outcomes in clinical trials and rehabilitation involving persons with multiple sclerosis (MS). However, assessments conducted in controlled settings may not reflect real-world capacity and movement in a natural environment. Peak cadence via accelerometry might represent a novel measure of walking intensity and prolonged natural effort under free-living conditions. Objective We compared peak 30-minute cadence, peak 1-minute cadence, and time spent in incremental cadence bands between persons with MS and healthy controls, and examined the associations between peak cadence and laboratory-assessed physical function and walking performance. Methods Participants (147 MS and 54 healthy controls) completed questionnaires on disability status and self-reported physical activity, underwent the Short Physical Performance Battery, Timed 25-Foot Walk, Timed Up and Go, and 6-Minute Walk, and wore an accelerometer for 7 days. We performed independent samples t-tests and Spearman bivariate and partial correlations adjusting for daily steps. Results The MS sample demonstrated lower physical function and walking performance scores, daily steps, and peak cadence (P < .001), and spent less time in purposeful steps and slow-to-brisk walking (40-119 steps/minutes), but accumulated more incidental movement (1-19 steps/minutes) than healthy controls. The associations between peak cadence and performance outcomes were strong in MS (|rs| = 0.59-0.68) and remained significant after controlling for daily steps (|prs| = 0.22-0.44), P-values < .01. Peak cadence was inversely correlated with age and disability, regardless of daily steps (P < .01). Conclusions Our findings provide preliminary evidence for the potential use of peak cadence with step-based metrics for comprehensively evaluating free-living walking performance in MS.

Effect of sprint interval training load on maximal oxygen uptake in trained men.

Sprint interval training (SIT) improves maximal aerobic and anaerobic performance, including oxygen uptake (VO2<inf>max</inf>), power output, and sprint performance. This study aimed to investigate the effect of SIT load on V̇O<inf>2max</inf> in trained subjects. SIT was performed twice a week for three weeks by twenty-four trained men (aged: 20.7±2.7, V̇O<inf>2max</inf> 43.6±6.5) and consisted of seven bouts of 10-s cycling sprints followed by a 4-min rest. Subjects were divided into two groups depending on the relative resistance of the load compared to their body mass (BM): 7.5% (S7.5) and 10% (S10). We measured the peak power, mean power, and peak cadence in SIT during the first and final sessions. V̇O<inf>2max</inf>, maximum aerobic power (MAP), heart rate, and lactate (La) concentration were measured before and after SIT using incremental tests. After 3 weeks of SIT, V̇O<inf>2max</inf>, MAP, and La improved significantly in both S7.5 and S10 groups. In addition, changes in V̇O<inf>2max</inf> in S10 were higher than those in S7.5 (2.2±11.2% vs. 9.23±9.57%, P=0.029, adjusted by pre V̇O<inf>2max</inf>). MAP measurements showed the same results (2.2±11.3% vs. 8.3±10.0%, P=0.015, adjusted by pre-MAP). However, there was no significant interaction between time and group. A significant increase in peak cadence from first session to sixth sessions was observed in S7.5 (P=0.01, ES = 0.93, 95% confidence interval [CI]: 0.02-1.78) but not in S10 (P=0.132, ES = 0.22, 95% [CI]: -0.59-1.01). Our results suggest that 3 weeks of SIT improves endurance performance in trained subjects. It seems that SIT at 10% load may tend to be more effective.

Walking more, not faster, is associated with bone health in China of community-dwelling older women:A cross-sectional study

AimsTo examine the association between daily steps and step intensity with bone health in Chinese community-dwelling older women. MethodsData from 1116 women in the Physical Activity and Health in Older Women Study in China, 2021. Three bone parameters: bone quality index (BQI), speed of sound (SOS), and broadband ultrasound attenuation (BUA) were measured in the left heel using an ultrasound bone densitometer and transformed into dichotomous variables from medians. Daily steps and step intensity (slow step time, brisk step time, peak 1-min cadence, peak 30-min cadence, and peak 60-min cadence) were measured using a triaxial accelerometer. Participants with high BQI, SOS, and BUA levels were used as references for logistic regression models to explore the association of daily steps and step intensity with bone health. ResultsDaily steps were positively associated with the BQI (odds ratio [OR] = 0.94, confidence interval [CI] = 0.89,1.00), SOS (OR = 0.93, CI = 0.88,0.99), and BUA (OR = 0.93, CI = 0.88,0.99) among older women. There was no significant association between peak cadence and bone health. Slow step time was positively associated with the BQI (OR = 0.94, CI = 0.90,0.99) and SOS (OR = 0.93, CI = 0.88,0.97), while brisk step time was positively associated with the BQI (OR = 0.89, CI = 0.82,0.97), SOS (OR = 0.87, CI = 0.80,0.94), and BUA (OR = 0.89, CI = 0.82,0.97). Moreover, 10,000 steps/day or more was significantly associated with the BQI (OR = 0.52, CI = 0.33,0.81), SOS (OR = 0.55, CI = 0.35,0.86), and BUA (OR = 0.45, CI = 0.28, 0.70) compared to <6000 steps/day. ConclusionIncreasing the number of daily steps or the duration of walking, whether fast or slow, may benefit the bone health of older women.

The relationships between Physical activity and asthma control and Body Mass Index (BMI) in patients with asthma

Objective Asthma is one of the most common chronic conditions in developed countries. We examined whether physical activity (PA) is related to asthma control and body mass index (BMI) in asthma patients. Methods Cross-sectional data collected on PA (ActiGraph GT3X-BT), asthma control (the Asthma Control Questionnaire; ACQ), and BMI were examined in 206 adults (mean[sd] age 47.2[13.8] years; 49.5% had an obese BMI) with clinically diagnosed asthma. Relationships between PA and continuous BMI and asthma control were assessed using linear regression. Differences in PA across obesity (non-obese: <30 Kg/m2/obese: ≥30 Kg/m2) and asthma control categories (controlled: ≤0.75/uncontrolled: >0.75 ACQ score) were also examined. Results Median (p25, p75) steps counts and peak cadence were 6035 (4248, 8461) steps/day and 123 (115, 133) steps in a minute, respectively. There were nearly 2000 fewer steps/day among those with uncontrolled asthma versus controlled and among those with obese BMI versus nonobese, respectively (both p < 0.05). In regression models adjusted for relevant covariates each 1-unit increase in ACQ score was associated with −686 [95%CI −997, −13] (p ≤ 0.05) average steps/day. The statistical significance of these findings was attenuated (p ≥ 0.05) when BMI was added to the model. However, the point estimate was not reduced (-766 [95%CI −1060, 34]. Conclusions Overall step counts were low in this population despite peak cadence values suggesting that most participants could perform moderate intensity activity. Increasing step counts should be considered an important lifestyle intervention goal in obese and non-obese asthma patients with low PA levels.

Daily step volume and intensity moderate the association of sedentary time and cardiometabolic disease risk in community-dwelling older adults: A cross-sectional study

ObjectiveTo investigate the moderating effect of step count and peak cadence on the relationship of sedentary time and cardiometabolic disease risk in community-dwelling older adults. MethodsThis cross-sectional study included 248 older adults aged 60–80 years without cardiovascular disease (66.0 ± 4.6 years of age; 78 % females). Sedentary time, step count and peak cadence were measured by a hip-worn accelerometer for seven days. Peak cadence was defined as the average of 30 min of the day (but not necessarily consecutive) with the highest cadence (steps per minute) for all valid days. Cardiometabolic disease risk was defined using a sex-specific continuous metabolic syndrome score (cMetS). Sedentary time was used as an explanatory variable for cMetS and step count and peak cadence as moderators. The analyses were adjusted for known cardiometabolic disease risk factors and accelerometer wear time. The Johnson-Neyman technique was used to specify the value of moderator variables at which the significant relationship between sedentary time and cMetS disappears. ResultsBoth step count (β = −0.186, P = 0.032) and peak cadence (β = −0.003, P = 0.007) showed a moderating effect on the relationship of sedentary time and cMetS. The association of sedentary time and cMetS was not statistically significant (p > 0.05) when step count or peak cadence exceed 5715 steps per day and 57 steps per minute, respectively. ConclusionSteps per day and peak cadence moderate the association of sedentary time and cardiometabolic disease risk in older adults. Therefore, steps per day and peak cadence seem to offset the deleterious effects of sedentary time on cardiometabolic health in this population.

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Associations of steps per day and peak cadence with arterial stiffness in older adults.

There is evidence showing an inverse association between steps/day and arterial stiffness in adults. However, the relationship of steps/day and peak cadence with arterial stiffness is poorly understood in older adults. This study aimed to investigate the association between steps/day and peak cadence with arterial stiffness in older adults. This cross-sectional study included 222 community-dwelling older adults (66±5years; 81.5% females; 70.3% with hypertension). Arterial stiffness was measured by aortic pulse wave velocity (aPWV). Steps/day and peak cadence were assessed by accelerometry. The participants were categorized according to the number of steps/day: sedentary <5000; low active 5000-7499; active 7500-9999; highly active 10,000+. Peak cadence was defined as the average of steps/day of the highest 30min (not necessarily consecutive) for all valid days. Generalized linear models were used for data analyses. The active (β=-0.34m/s, 95% CI -0.60, -0.08) and highly active (β=-0.51m/s, 95% CI -0.83, -0.20) groups had lower aPWV compared to the sedentary group. No significant difference was found between the low active group and the sedentary group (β=-0.21m/s, 95% CI -0.46, 0.05). Every increment of 1000steps/day was associated with a decrease of 0.05m/s in the aPWV (95% CI -0.08, -0.02). Every increment of 10 steps/min in peak 30-min cadence was associated with a decrease of 0.05m/s in aPWV (95% CI -0.09, -0.01). Our findings show that easy-to-use proxies of the volume (steps/day) and intensity (peak cadence) of ambulatory behavior are inversely associated with arterial stiffness in older adults. The inverse association of steps/day and peak cadence with arterial stiffness is dose-response.

Rates of neuromuscular excitation during cycling in Parkinson's disease compared to healthy young and older adults

BackgroundBradykinesia affects mobility in some people with Parkinson's. Fall risk makes the neural control of maximal speed ambulatory movements difficult to study in Parkinson's. Stationary recumbent bicycling favors the use of electromyography at high movement speeds, and may better reveal neuromuscular rate limiters. MethodsSubjects were 18 adults with Parkinson's, 14 older adults and 14 young adults. Electromyograms were recorded from two muscles during stationary recumbent bicycling at 60, 80, 100, 120 RPM and peak voluntary cadence. Rate of electromyogram rise was calculated. Subjects performed the timed up and go and four square step test. Parkinson's sub-groups were formed based on whether they could pedal ≥120 RPM. Mixed models were used to compare groups and spearman's correlations quantified relationships. FindingsEight people with Parkinson's and four older adults could not complete the 120 RPM condition. Faster people with Parkinson's (n = 10) had greater maximum cadence (F = 42.85, P < 0.05), higher rates of electromyogram rise in both muscles (F > 16.9, P < 0.05), and faster mobility test times (F > 6.5, P < 0.05) than slower people with Parkinson's (n = 8). In Parkinson's, correlations between vastus lateralis rate of electromyogram rise and four square step test (ρ = −0.62), timed up and go (ρ = −0.53), and peak cadence (ρ = 0.76) were significant (all P < 0.05). InterpretationPeople with Parkinson's with slower peak pedaling cadence had slower mobility performance and lower vastus lateralis excitation rates at higher cadences. Vastus lateralis excitation rates had moderate to strong relationships with peak cadence and mobility. Exercise interventions may seek to improve peak cadence or excitation rates in people with Parkinson's.

Validity of the Favero Assioma Duo Power Pedal System for Measuring Power Output and Cadence.

Cycling power meters enable monitoring external loads and performance changes. We aimed to determine the concurrent validity of the novel Favero Assioma Duo (FAD) pedal power meter compared with the crank-based SRM system (considered as gold standard). Thirty-three well-trained male cyclists were assessed at different power output (PO) levels (100–500 W and all-out 15-s sprints), pedaling cadences (75–100 rpm) and cycling positions (seating and standing) to compare the FAD device vs. SRM. No significant differences were found between devices for cadence nor for PO during all-out efforts (p > 0.05), although significant but small differences were found for efforts at lower PO values (p < 0.05 for 100–500 W, mean bias 3–8 W). A strong agreement was observed between both devices for mean cadence (ICC > 0.87) and PO values (ICC > 0.81) recorded in essentially all conditions and for peak cadence (ICC > 0.98) and peak PO (ICC > 0.99) during all-out efforts. The coefficient of variation for PO values was consistently lower than 3%. In conclusion, the FAD pedal-based power meter can be considered an overall valid system to record PO and cadence during cycling, although it might present a small bias compared with power meters placed on other locations such as SRM.

Impact of Graded Passive Cycling on Hemodynamics, Cerebral Blood Flow, and Cardiac Function in Septic ICU Patients.

Background: In-bed passive cycling is considered a safe and feasible early mobilization technique in intensive care unit (ICU) patients who are unable to exercise actively. However, the impact of varying intensity of passive cycling on perfusion and function of ischemia-prone organs is unknown. In this study, we assessed the impact of a graded passive cycling protocol on hemodynamics, cerebral blood flow, and cardiac function in a cohort of septic ICU patients.Methods: In consecutive patients presenting with sepsis, we measured global hemodynamic indices, middle cerebral artery velocity (MCAv), and cardiac function in response to a graded increase in passive cycling cadence. Using 5-min stages, we increased cadence from 5 to 55 RPM in increments of 10 RPM, preceded and followed by 5 min baseline and recovery periods at 0 RPM. The mean values obtained during the last 2 min of each stage were compared within and between subjects for all metrics using repeated-measures ANOVA.Results: Ten septic patients (six males) completed the protocol. Across patients, there was a 5.2% reduction in MCAv from baseline at cycling cadences of 25–45 RPM with a dose-dependent decrease of MCAv of > 10% in four of the 10 patients enrolled. There was a 16% increase in total peripheral resistance from baseline at peak cadence of 55 RPMs and no changes in any other measured hemodynamic parameters. Patient responses to passive cycling varied between patients in terms of magnitude, direction of change, and the cycling cadence at which these changes occurred.Conclusions: In septic patients, graded passive cycling is associated with dose-dependent decreases in cerebral blood flow, increases in total peripheral resistance, and either improvement or worsening of left ventricular function. The magnitude and cadence threshold of these responses vary between patients. Future studies should establish whether these changes are associated with clinical outcomes, including cognitive impairment, vasopressor use, and functional outcomes.

No effect of cycling shoe sole stiffness on sprint performance

Most competitive and recreational road cyclists use stiff-soled shoes designed for cycling and ‘clipless’ pedals that firmly attach to the shoes. There are many unsubstantiated claims by cyclists and industry professionals about the advantages of cycling shoes and clipless pedals. Scientific research has shown that cycling shoes and clipless pedals have no significant effects on the metabolic cost of cycling during submaximal, steady-state efforts. However, a recent study demonstrated that, compared to running shoes, cycling shoes and clipless pedals do provide performance benefits relevant to sprint cycling. Here, we investigated if there was a positive relationship between longitudinal bending stiffness of cycling shoe soles and sprint performance. We measured the mechanical power outputs, velocities, and cadences of 19 healthy male recreational/competitive cyclists during maximal sprint cycling. All participants rode outdoors on a paved asphalt road with a steady, uphill grade of 4.9%. Each subject completed a total of nine 50 m cycling sprints in three (single-blinded) shoe conditions (each condition was replicated three times): identical shoe uppers with injection moulded nylon soles, carbon fibre-fibreglass blend soles, and full carbon fibre soles. The same clipless pedals were used throughout all tests. No significant differences were detected between the three shoe soles for: 50 m average and peak 1-second power, average change and peak change in velocity, average and peak cadence, maximal sprint velocity, peak acceleration, and peak crank torque (all p > 0.31). Greater longitudinal bending stiffness of cycling shoe soles had no effect on sprint performance during short uphill sprints.

Effects of an mHealth Brisk Walking Intervention on Increasing Physical Activity in Older People With Cognitive Frailty: Pilot Randomized Controlled Trial

BackgroundCognitive frailty is the coexistence of physical frailty and cognitive impairment and is an at-risk state for many adverse health outcomes. Moderate-to-vigorous physical activity (MVPA) is protective against the progression of cognitive frailty. Physical inactivity is common in older people, and brisk walking is a feasible form of physical activity that can enhance their MVPA. Mobile health (mHealth) employing persuasive technology has been successful in increasing the levels of physical activity in older people. However, its feasibility and effects on older people with cognitive frailty are unclear.ObjectiveWe aimed to identify the issues related to the feasibility of an mHealth intervention and the trial (ie, recruitment, retention, participation, and compliance) and to examine the effects of the intervention on cognitive function, physical frailty, walking time, and MVPA.MethodsAn open-label, parallel design, randomized controlled trial (RCT) was employed. The eligibility criteria for the participants were age ≥60 years, having cognitive frailty, and having physical inactivity. In the intervention group, participants received both conventional behavior change intervention and mHealth (ie, smartphone-assisted program using Samsung Health and WhatsApp) interventions. In the control group, participants received conventional behavior change intervention only. The outcomes included cognitive function, frailty, walking time, and MVPA. Permuted block randomization in 1:1 ratio was used. The feasibility issue was described in terms of participant recruitment, retention, participation, and compliance. Wilcoxon signed-rank test was used to test the within-group effects in both groups separately.ResultsWe recruited 99 participants; 33 eligible participants were randomized into either the intervention group (n=16) or the control (n=17) group. The median age was 71.0 years (IQR 9.0) and the majority of them were females (28/33, 85%). The recruitment rate was 33% (33/99), the participant retention rate was 91% (30/33), and the attendance rate of all the face-to-face sessions was 100% (33/33). The majority of the smartphone messages were read by the participants within 30 minutes (91/216, 42.1%). ActiGraph (58/66 days, 88%) and smartphone (54/56 days, 97%) wearing compliances were good. After the interventions, cognitive function improvement was significant in both the intervention (P=.003) and the control (P=.009) groups. The increase in frailty reduction (P=.005), walking time (P=.03), step count (P=.02), brisk walking time (P=.009), peak cadence (P=.003), and MVPA time (P=.02) were significant only in the intervention group.ConclusionsOur mHealth intervention is feasible for implementation in older people with cognitive impairment and is effective at enhancing compliance with the brisk walking training program delivered by the conventional behavior change interventions. We provide preliminary evidence that this mHealth intervention can increase MVPA time to an extent sufficient to yield clinical benefits (ie, reduction in cognitive frailty). A full-powered and assessor-blinded RCT should be employed in the future to warrant these effects.Trial RegistrationHKU Clinical Trials Registry HKUCTR-2283; http://www.hkuctr.com/Study/Show/31df4708944944bd99e730d839db4756

Longitudinal changes in walking cadence across pregnancy and postpartum

BackgroundPhysical activity during pregnancy has many health benefits yet few pregnant women meet US guidelines for physical activity. Traditionally, physical activity has been measured as time spent in moderate and/or vigorous intensity activity, but quantifying intensity is challenging. There is increasing interest in measuring both daily steps and stepping rate, or cadence, as an indicator of physical activity overall and intensity of that activity. Research question: Does free-living step cadence change across pregnancy (from 20 weeks to 32 weeks) and postpartum (12 weeks postpartum) when data is collected via hip-worn ActiGraph (ActiGraph Corp., Pensacola, FL) accelerometers? Methods: A total of n = 32 pregnant women were enrolled in a longitudinal study of physical activity during pregnancy; these women wore accelerometers on their right hip for one week at 20 weeks gestation, again at 32 weeks gestation, and at 12 weeks postpartum. Data were used to determine total daily steps, time spent (min/day) in various cadence ranges, minutes spent at >100 and >130 steps/min as well as mean, median, maximum, and peak cadences. Results: Pregnant women accumulated significantly fewer steps per day in the third trimester compared to second (1164 steps/day less) or postpartum (1397 steps/day less) time points. Third trimester women also spent significantly fewer minutes/day in MVPA (cadences ≥100 steps/minute; 4.1 min/day less) and had a significantly lower peak cadence (10.6 steps/min less), compared to second trimester only. Significance: These data indicate that pregnant women take fewer steps and walk at slower cadences in the third trimester compared to second and to postpartum, which indicates that total PA as well as absolute intensity of PA are altered during pregnancy.

Step-Based Metrics and Overall Physical Activity in Children With Overweight or Obesity: Cross-Sectional Study.

BackgroundBest-practice early interventions to increase physical activity (PA) in children with overweight and obesity should be both feasible and evidence based. Walking is a basic human movement pattern that is practical, cost-effective, and does not require complex movement skills. However, there is still a need to investigate how much walking—as a proportion of total PA level—is performed by children who are overweight and obese in order to determine its utility as a public health strategy.ObjectiveThis study aimed to (1) investigate the proportion of overall PA indicators that are explained by step-based metrics and (2) study step accumulation patterns relative to achievement of public health recommendations in children who are overweight and obese.MethodsA total of 105 overweight and obese children (mean 10.1 years of age [SD 1.1]; 43 girls) wore hip-worn accelerometers for 7 days. PA volumes were derived using the daily average of counts per 15 seconds, categorized using standard cut points for light-moderate-vigorous PA (LMVPA) and moderate-to-vigorous PA (MVPA). Derived step-based metrics included volume (steps/day), time in cadence bands, and peak 1-minute, 30-minute, and 60-minute cadences.ResultsSteps per day explained 66%, 40%, and 74% of variance for counts per 15 seconds, LMVPA, and MVPA, respectively. The variance explained was increased up to 80%, 92%, and 77% by including specific cadence bands and peak cadences. Children meeting the World Health Organization recommendation of 60 minutes per day of MVPA spent less time at zero cadence and more time in cadence bands representing sporadic movement to brisk walking (ie, 20-119 steps/min) than their less-active peers.ConclusionsStep-based metrics, including steps per day and various cadence-based metrics, seem to capture a large proportion of PA for children who are overweight and obese. Given the availability of pedometers, step-based metrics could be useful in discriminating between those children who do or do not achieve MVPA recommendations.Trial RegistrationClinicalTrials.gov NCT02295072; https://clinicaltrials.gov/ct2/show/NCT02295072

Objective measures of moderate to vigorous physical activity are associated with higher distal limb bone strength among elderly men.

Our aim was to determine the association between objectively measured physical activity (PA) and bone strength of the distal limbs among older men. We studied 994 men from the MrOS cohort study (mean age 83.9) who had repeat (Year 7 and 14) 5-day activity assessment with at least 90% wear time (SenseWearPro3 Armband) and Year 14 measures using high resolution peripheral quantitative tomography (HR-pQCT) (Scanco). Total energy expenditure (TEE), total steps per day, peak cadence (mean of top 30steps/min over 24h) and time spent in a given level of activity: sedentary (reference, <1.5 metabolic equivalents of task [METs]), light (1.5 to <3 METs), or moderate to vigorous physical activity(MVPA: ≥3 METs) were calculated as mean over the two time points. Estimated failure load was determined from HR-pQCT data using finite element analysis. We used standardized variables and adjusted for potential confounders using linear regression. The means ±SDs for daily activity were: 2338±356kcal/d [TEE]; 5739±2696steps/day [step count], 60±20cpm [peak cadence], 67±28min/d [light activity], and 85±52min/d [MVPA]. Higher TEE, step count, and peak cadence were each associated with higher failure load of the distal radius (effect sizes respectively: 0.13 [95% CI: 0.05, 0.20], 0.11 [95% CI: 0.04, 0.18], and 0.08 [95% CI: 0.01, 0.15]) and higher failure load of the distal tibia (effect sizes respectively 0.21 [95% CI: 0.13, 0.28], 0.19 [95% CI: 0.13, 0.26], 0.19 [95% CI, 0.13, 0.25]). Time spent in MVPA vs. time sedentary was related to bone strength at both sites after adjustment, whereas time spent in light activity vs. time sedentary was not. TEE was associated with compartmental area and BMD parameters at distal tibia, but only area parameters at the distal radius. In summary, MVPA over a 7-year period of time may have a modest association with bone strength and geometry among older men.