Reliability and minimal detectable change of a new treadmill-based progressive workload incremental test to measure cardiorespiratory fitness in manual wheelchair users

Topical Cellular/Tissue and Molecular Aspects Regarding Nonpharmacological Interventions in Alzheimer's Disease-A Systematic Review

One of the most complex and challenging developments at the beginning of the third millennium is the alarming increase in demographic aging, mainly-but not exclusively-affecting developed countries. This reality results in one of the harsh medical, social, and economic consequences: the continuously increasing number of people with dementia, including Alzheimer's disease (AD), which accounts for up to 80% of all such types of pathology. Its large and progressive disabling potential, which eventually leads to death, therefore represents an important public health matter, especially because there is no known cure for this disease. Consequently, periodic reappraisals of different therapeutic possibilities are necessary. For this purpose, we conducted this systematic literature review investigating nonpharmacological interventions for AD, including their currently known cellular and molecular action bases. This endeavor was based on the PRISMA method, by which we selected 116 eligible articles published during the last year. Because of the unfortunate lack of effective treatments for AD, it is necessary to enhance efforts toward identifying and improving various therapeutic and rehabilitative approaches, as well as related prophylactic measures.

Minimal Detectable Change in Resting Blood Pressure and Cardiorespiratory Fitness: A Secondary Analysis of a Study on School-Based High-Intensity Interval Training Intervention

High-intensity interval training (HIIT) effects on resting blood pressure (BP) and cardiorespiratory fitness (CRF) have already been studied. Furthermore, the responses of responders and non-responders to HIIT in terms of these physiological outcomes have also been examined. However, the minimal detectable change (MDC) in BP and CRF has not been addressed yet. Therefore, the current study aimed to compare the MDC90 of BP (systolic and diastolic) and CRF (fitness index (FI) results) in the context of a school-based HIIT program for adolescents. Participants were adolescents, with an average age of 16.16 years (n = 141; 36.6% males). A preplanned secondary analysis was conducted using pre-post data from the control group to estimate MDC90. The MDC90 of SBP, DBP, and FI were 7.82 mm HG, 12.45 mm HG, and 5.39 points, respectively. However, taking into account the relative values of these changes, MDC90 required a greater change in DBP (17.27%) than FI (12.15%) and SBP (6.68%). Any training-induced physiological changes in the average values of the outcomes did not exceed MDC90. However, a comparison of the participants who exceeded and did not exceed MDC90 showed statistically significant differences. These findings reveal the huge variability in and insensitivity to the intervention effect for all measurements. This is likely because of the large subgroup of participants with low sensitivity to the physiological stimulus. As such, there is a considerable need to create individually tailored intervention programs.

Test-Retest Reliability of Physiological Variables During Submaximal Seated Upper-Body Poling in Able-Bodied Participants

Purpose: To investigate the test–retest reliability of physiological variables across four different test days and four different submaximal exercise intensities during seated upper-body poling (UBP).

Methods: Thirteen abled-bodied, upper-body trained men (age 29±3years; body mass 84±12kg; height 183±5cm) performed four submaximal 4-min stages of seated UBP on four separate test days. The four submaximal stages were set at individual power outputs corresponding to a rating of perceived exertion of 9, 11, 13, and 15. The absolute reliability for pairwise test-day comparisons of the physiological variables was investigated with the smallest detectable change percentage (%SDC) and the relative reliability with the interclass correlation coefficient (ICC).

Results: Absolute and relative reliability across test-day comparisons and submaximal stages were moderate to excellent for all variables investigated (V̇O₂ – %SDC range: 5–13%, ICC range: 0.93–0.99; HR – %SDC range: 6–9%, ICC range: 0.91–0.97) other than blood lactate, for which absolute reliability was poor and relative reliability highly variable (%SDC range: 26–69%, ICC range: 0.44–0.92). Furthermore, absolute and relative reliability were consistent across the low-to-moderate exercise intensity spectrum and across test days.

Conclusion: Absolute and relative test–retest reliability were acceptable for all investigated physiological variables but blood lactate. The consistent test–retest reliability across the exercise intensity spectrum and across test days indicates that a familiarization period to the specific exercise modality may not be necessary. For generalizability, these findings need to be confirmed in athletes with a disability by future large-scale studies.

Changes to Biceps and Supraspinatus Tendons in Response to a Progressive Maximal Treadmill-Based Propulsion Aerobic Fitness Test in Manual Wheelchair Users: A Quantitative Musculoskeletal Ultrasound Study

Objective

To investigate if the completion of a recently developed treadmill-based wheelchair propulsion maximal progressive workload incremental test alters the integrity of the long head of the biceps and supraspinatus tendons using musculoskeletal ultrasound imaging biomarkers.

Method

Fifteen manual wheelchair users completed the incremental test. Ultrasound images of the long head of the biceps and supraspinatus tendons were recorded before, immediately after, and 48 hours after the completion of the test using a standardized protocol. Geometric, composition, and texture-related ultrasound biomarkers characterized tendon integrity.

Results

Participants propelled during 10.2 ± 2.9 minutes with the majority (N = 13/15) having reached at least the eighth stage of the test (speed = 0.8 m/s; slope = 3.6°). All ultrasound biomarkers characterizing tendon integrity, measured in the longitudinal and transversal planes for both tendons, were similar (p = 0.063 to 1.000) across measurement times.

Conclusion

The performance of the motorized treadmill wheelchair propulsion test to assess aerobic fitness produced no changes to ultrasound biomarkers of the biceps or supraspinatus tendons. Hence, there was no ultrasound imaging evidence of a maladaptive response due to overstimulation in these tendons immediately after and 48 hours after the performance of the test.

The test-retest reliability of individualized VO2peak test modalities in people with spinal cord injury undergoing rehabilitation

STUDY DESIGN

Test-retest study.

OBJECTIVE

To describe the test-retest reliability of an individualized approach for peak oxygen uptake (VO₂peak) testing in a clinical context, accommodating inpatients with heterogeneous levels of physical functioning.

SETTING

Inpatient rehabilitation.

METHOD

Test-retest on two types of devices (recumbent stepper and arm-crank ergometer) with two predefined protocols of varying load increments on each device. No participants performed all four test modalities. VO₂peak, respiratory exchange ratio (RER), peak workload, and the reason for termination were reported. Of 23 participants included, 21 completed the test-retest procedure. Participants were inpatients, ≥18 years, who sustained a spinal cord injury (SCI) within the last 12 months at the time of admission. The median age was 52 years and 74% were male. Median time since injury at the time of the first test (T1) was 5.5 months. Seventeen were classified as American Spinal Injury Association Impairment Scale D. Intraclass correlation coefficients (ICC) and Bland-Altman plots for VO₂peak was calculated to determine intra- and intertester reliability of VO₂peak.

RESULTS

Mean VO₂peak obtained at T1 was 1.91 L/min (95%CI: 1.31-2.51); 1.26 L/min and 2.69 L/min for the recumbent stepper protocols; 0.61 L/min and 1.39 L/min for the arm-crank ergometer protocols. ICC for intra- and intertester reliability was 0.997 (95%CI: 0.986-0.999) and 0.994 (95%CI: 0.978-0.998) respectively. Bland-Altman plots showed a mean difference of -0.005 (SD 0,12) for overall test-retest.

CONCLUSION

Test-retest reliability was high. Mean VO₂peak at discharge from rehabilitation was higher than previously reported and individualized test modalities seemed to yield more optimal results in a heterogenous and representative sample during rehabilitation.

Effects of different increments in workload and duration on peak physiological responses during seated upper-body poling

PURPOSE

To compare the effects of test protocols with different increments in workload and duration on peak oxygen uptake ([Formula: see text]O_2peak), and related physiological parameters during seated upper-body poling (UBP).

METHODS

Thirteen upper-body trained, male individuals completed four UBP test protocols with increments in workload until volitional exhaustion in a counterbalanced order: 20 W increase/every 30 s, 20 W/60 s, 10 W/30 s and 10 W/60 s. Cardio-respiratory parameters and power output were measured throughout the duration of each test. Peak blood lactate concentration (bLa_peak) was measured after each test.

RESULTS

The mixed model analysis revealed no overall effect of test protocol on [Formula: see text]O_2peak, peak minute ventilation (VE_peak), peak heart rate (HR_peak), bLa_peak (all p ≥ 0.350), whereas an overall effect of test protocol was found on peak power output (PO_peak) (p = 0.0001), respiratory exchange ratio (RER) (p = 0.024) and test duration (p < 0.001). There was no difference in PO_peak between the 20 W/60 s (175 ± 25 W) and 10 W/30 s test (169 ± 27 W; p = 0.092), whereas PO_peak was lower in the 10 W/60 s test (152 ± 21 W) and higher in the 20 W/30 s test (189 ± 30 W) compared to the other tests (all p = 0.001). In addition, RER was 9.9% higher in the 20 W/30 s compared to the 10 W/60 s test protocol (p = 0.003).

CONCLUSIONS

The UBP test protocols with different increments in workload and duration did not influence [Formula: see text]O_2peak, and can therefore be used interchangeably when [Formula: see text]O_2peak is the primary outcome. However, PO_peak and RER depend upon the test protocol applied and the UBP test protocols can, therefore, not be used interchangeably when the latter is the primary outcome parameter.

Defining accelerometer cut-points for different intensity levels in motor-complete spinal cord injury

STUDY DESIGN

Descriptive.

OBJECTIVE

The present aim was to define accelerometer cut-point values for wrist-worn accelerometers to identify absolute- and relative-intensity physical activity (PA) levels in people with motor-complete paraplegics (PP) and tetraplegics (TP).

SETTINGS

Rehabilitation facility in Sweden.

METHODS

The participants were 26 (19 men, 7 women) with C5-C8, AIS A and B (TP) and 37 (27 men, 10 women) with T7-T12 (PP), AIS A and B. Wrist-worn accelerometer recordings (Actigraph GT3X+) were taken during seven standardized activities. Oxygen consumption was measured, as well as at-rest and peak effort, with indirect calorimetry. Accelerometer cut-points for absolute and relative intensities were defined using ROC-curve analyses.

RESULTS

The ROC-curve analyses for accelerometer cut-points revealed good-to-excellent accuracy (AUC >0.8), defining cut-points for absolute intensity (2, 3, 4, 5, 6, 7 METs for PP and 2 to 6 METs for TP) and relative intensity (30, 40, 50, 60, 70, and 80% for PP and 40-80% for TP). The cut-points for moderate-to-vigorous physical activity was defined as ≥9515 vector magnitude counts per minute (VMC) for PP and ≥4887 VMC/min for TP.

CONCLUSION

This study presents cut-points for wrist-worn accelerometers in both PP and TP, which could be used in clinical practice to describe physical activity patterns and time spent at different intensity levels.

Feasibility, Safety, and Preliminary Effectiveness of a Home-Based Self-Managed High-Intensity Interval Training Program Offered to Long-Term Manual Wheelchair Users

Objectives

To investigate and compare the feasibility, safety, and preliminary effectiveness of home-based self-managed manual wheelchair high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) programs.

Methods

Eleven manual wheelchair users were randomly assigned to the HIIT (n = 6) or the MICT group (n = 5). Both six-week programs consisted of three 40-minute propulsion training sessions per week. The HIIT group alternated between 30 s high-intensity intervals and 60 s low-intensity intervals, whereas the MICT group maintained a constant moderate intensity. Cardiorespiratory fitness, upper limb strength, and shoulder pain were measured before and after the programs. Participants completed a questionnaire on the programs that explored general areas of feasibility.

Results

The answers to the questionnaire demonstrated that both training programs were feasible in the community. No severe adverse events occurred, although some participants experienced increased shoulder pain during HIIT. Neither program yielded a significant change in cardiorespiratory fitness or upper limb strength. However, both groups reported moderate to significant subjective improvement.

Conclusion

Home-based wheelchair HIIT appears feasible and safe although potential development of shoulder pain remains a concern and should be addressed with a future preventive shoulder exercise program. Some recommendations have been proposed for a larger study aiming to strengthen evidence regarding the feasibility, safety, and effectiveness of HIIT.