High-Intensity Interval Cycle Ergometer Training in Parkinson's Disease: Protocol for Identifying Individual Response Patterns Using a Single-Subject Research Design

(HIIT-The Track) High-Intensity Interval Training for People with Parkinson's Disease: Individual Response Patterns of (Non-)Motor Symptoms and Blood-Based Biomarkers-A Crossover Single-Case Experimental Design

INTRODUCTION

Physical exercise is receiving increasing interest as an augmentative non-pharmacological intervention in Parkinson's disease (PD). This pilot study primarily aimed to quantify individual response patterns of motor symptoms to alternating exercise modalities, along with non-motor functioning and blood biomarkers of neuroplasticity and neurodegeneration.

MATERIALS & METHODS

People with PD performed high-intensity interval training (HIIT) and continuous aerobic exercise (CAE) using a crossover single-case experimental design. A repeated assessment of outcome measures was conducted. The trajectories of outcome measures were visualized in time series plots and interpreted relative to the minimal clinically important difference (MCID) and smallest detectable change (SDC) or as a change in the positive or negative direction using trend lines.

RESULTS

Data of three participants were analyzed and engaging in physical exercise seemed beneficial for reducing motor symptoms. Participant 1 demonstrated improvement in motor function, independent of exercise modality; while for participant 2, such a clinically relevant (positive) change in motor function was only observed in response to CAE. Participant 3 showed improved motor function after HIIT, but no comparison could be made with CAE because of drop-out. Heterogeneous responses on secondary outcome measures were found, not only between exercise modalities but also among participants.

CONCLUSION

Though this study underpins the positive impact of physical exercise in the management of PD, large variability in individual response patterns to the interventions among participants makes it difficult to identify clear exercise-induced adaptations in functioning and blood biomarkers. Further research is needed to overcome methodological challenges in measuring individual response patterns.

Graded peak cycle ergometer test for cognitively impaired patients with Parkinson's disease: a pilot study

BACKGROUND

Cognitive decline affects up to 50% of patients with Parkinson's disease (PD) in the course of the disease and may be amenable to exercise interventions. To accurately set adequate training intensities, standardized exercise testing is required but such testing takes considerable time and effort. The aim of this pilot study was to investigate the feasibility of a graded peak cycle ergometer exercise test in cognitively impaired patients with Parkinson's Disease (PD), and to define whether age-predicted maximal heart rate (HRmax) matched measured HRmax.

METHODS

A convenience sample of seven patients with PD (Hoehn and Yahr: 2-4, and cognitive impairment (Montreal Cognitive Assessment (MoCA) ≤ 26) completed a graded peak cycle ergometer test to voluntary exhaustion. Borg Rating of Perceived Exertion was used to record the individual's perception of exertion. Pre-defined age-predicted HRmax (calculated as 208-(0.7 × age) was compared with the measured HRmax using Bland-Altman plot and a two-one-sided test.

RESULTS

All PD patients completed the graded exercise test between 8-12 minutes, showing therefore 100% compliance to the test protocol. No adverse events occurred. Predicted HRmax and measured HRmax did not differ.

CONCLUSION

We demonstrate feasibility of graded peak cycle ergometer testing in PD patients with cognitive impairment. The good correspondence of age-predicted HRmax equation with measured HRmax, in this small sample, may in the future provide clinicians with a tool to define training intensities in cognitively impaired PD, without cardiac disease. However, further research is needed to confirm these results.

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

BACKGROUND

Bradykinesia 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.

METHODS

Subjects 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.

FINDINGS

Eight 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).

INTERPRETATION

People 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.

Interactive Effects of Enalapril Administration and Novel HIIT Wheel-Bed Training in Aged Rats

INTRODUCTION

Growing research suggests that aerobic high-intensity interval training (HIIT) improves cardiovascular function and physical performance compared with moderate intensity continuous training (MICT). However relatively few animal models of HIIT are available to inform about the benefits of this exercise-particularly among older animals. In addition, there is little evidence for how HIIT training interacts with adjuvant pharmacological therapies known to enhance the impact of MCIT in older individuals such as Angiotensin Converting Enzyme (ACE) Inhibitors.

PURPOSE

The aim of the present study was to establish a HIIT protocol in aged rats based on forced running wheel-bed, and to subsequently (1) establish the feasibility of the HIIT protocol in a proof-of-concept study evaluating interactions between HIIT and (2) the result of combining HIIT + ACE inhibitor treatment using the ACE inhibitor enalapril.

METHODS

Two groups of rats were used in this study. The feasibility of using wheel-bed for HIIT training was tested in group one (15- and 30-month-old male rats). In the second group, 37 24-month-old Fisher 344 × Brown Norway male rats were randomly divided into four subgroups: control, enalapril, HIIT training group, and HIIT training combined with enalapril administration. The training and administration lasted for 4 weeks. After the intervention, locomotor activity, exercise tolerance, and grip strength were tested.

RESULTS

Our feasibility study suggested that middle-aged and aged rats were able to successfully complete the HIIT training. In our intervention study, HIIT training alone, regardless of adjuvant enalapril intervention, did raise treadmill exercise tolerance vs. the sedentary condition. Measures of healthspan were not negatively impacted by HIIT training.

CONCLUSION

The novel HIIT protocol based on forced running wheel-bed was successfully employed in aged rats. We conclude that future studies should compare the results and of multi-modal intervention strategies which include both HIIT and MICT in combination with adjuvant therapies such as enalapril to improve exercise tolerance and other global indices of healthspan.