Cardiorespiratory Fitness Benefits of High-Intensity Interval Training After Stroke: A Randomized Controlled Trial.

BACKGROUND: Limited evidence supports the effects of short-interval high-intensity interval training (HIIT) for improving cardiorespiratory fitness (V̇O2peak) after stroke. We aimed to compare the effects of 12 weeks of short-interval HIIT versus moderate-intensity continuous training (MICT) on V̇O2peak, cardiovascular risk factors, and mobility outcomes among individuals ≥6 months poststroke. METHODS: This study was a multi-site, 12-week randomized controlled trial (NCT03614585) with an 8-week follow-up. Participants were randomized into 3 d/wk of HIIT (10×1 minute 80%-100% heart rate reserve interspersed with 1 minute 30% heart rate reserve [19 minutes]) or MICT (20-30 minutes 40%-60% heart rate reserve). Secondary outcomes of the trial, including V̇O2peak, cardiovascular risk factors (carotid-femoral pulse wave velocity, blood pressure, and waist-hip ratio), and mobility (6-minute walk test, 10 m gait speed), were reported. Linear mixed model analyses with a group×study time point interaction evaluated between-group differences. RESULTS: Of the 305 potential participants, 82 consented (mean [SD] age 64.9 [9.3] years, 32 females [39%], 1.8 [1.2] years poststroke) and were randomized to HIIT (n=42, mean [SD] baseline V̇O2peak 17.3 [5.9] mL/kg·min) or MICT (n=40, mean [SD] baseline V̇O2peak 17.2 [6.0] mL/kg·min). Participants attended 82% of visits (n=2417/2952). No adverse events occurred during the study period. A significant group×study time point interaction was found (χ2=8.46; P=0.015) for V̇O2peak at 12 weeks (mean difference, 1.81 [95% CI, 0.58-3.04]; P=0.004) whereby the HIIT group had greater gains in V̇O2peak (∆3.52 mL/kg·min [95% CI, 2.47-4.57]; P<0.001) compared with the MICT group (∆1.71 mL/kg·min [95% CI, 0.55-2.86]; P=0.001). There was no between-group difference in V̇O2peak (mean difference, 1.08 [95% CI, -0.26 to 2.42]; P=0.11) at 8-week follow-up. No group×study time point interactions were found for cardiovascular risk factors or mobility outcomes. CONCLUSIONS: Short-interval HIIT may be an effective alternative to MICT for improving V̇O2peak at 12 weeks postintervention. REGISTRATION: URL: https://clinicaltrials.gov; Unique identifier: NCT03614585.

Validity of predischarge measures for predicting time to harm in older adults.

BACKGROUND: Concern is often expressed about the ability of persons with cognitive impairment to manage safely after discharge home from hospital. Measures validated for predicting safety are required. PURPOSE: The purpose of this study was to determine whether two predischarge functional measures were valid for predicting time to incident of harm after discharge. METHOD: Participants (n = 47) were recruited from an inpatient rehabilitation unit. The Assessment of Motor and Process Skills (AMPS) and Cognitive Performance Test (CPT) were administered in hospital. Incident-of-harm outcome was measured by caregiver telephone questionnaire monthly for 6 months. FINDINGS: Compared with all independent variables, AMPS Process scale was the best single predictor of time to incident of harm (p = .01). CPT had a high specificity (91%) for identifying persons who did not have harm. IMPLICATIONS: Both AMPS and CPT demonstrated predictive validity for harm outcome over less predictive variables, such as comorbidities and activities-of-daily-living burden of care.

Muscle weakness and falls in older adults: a systematic review and meta-analysis.

OBJECTIVES: To evaluate and summarize the evidence of muscle weakness as a risk factor for falls in older adults. DESIGN: Random-effects meta-analysis. SETTING: English-language studies indexed in MEDLINE and CINAHL (1985-2002) under the key words aged and accidental falls and risk factors; bibliographies of retrieved papers. PARTICIPANTS: Fifty percent or more subjects in a study were aged 65 and older. Studies of institutionalized and community-dwelling subjects were included. MEASUREMENTS: Prospective cohort studies that included measurement of muscle strength at inception (in isolation or with other factors) with follow-up for occurrence of falls. METHODS: Sample size, population, setting, measure of muscle strength, and length of follow-up, raw data if no risk estimate, odds ratios (ORs), rate ratios, or incidence density ratios. Each study was assessed using the validity criteria: adjustment for confounders, objective definition of fall outcome, reliable method of measuring muscle strength, and blinded outcome measurement. RESULTS: Thirty studies met the selection criteria; data were available from 13. For lower extremity weakness, the combined OR was 1.76 (95% confidence interval (CI)=1.31-2.37) for any fall and 3.06 (95% CI=1.86-5.04) for recurrent falls. For upper extremity weakness the combined OR was 1.53 (95% CI=1.01-2.32) for any fall and 1.41 (95% CI=1.25-1.59) for recurrent falls. CONCLUSION: Muscle strength (especially lower extremity) should be one of the factors that is assessed and treated in older adults at risk for falls. More clinical trials are needed to isolate whether muscle-strengthening exercises are effective in preventing falls.