Prescribing Aerobic Exercise Intensity without a Cardiopulmonary Exercise Test Post Stroke: Utility of the Six-Minute Walk Test.
BACKGROUND
The cardiopulmonary exercise test (CPET) is an established method for determining target exercise training intensity (ventilatory threshold [VAT]) and cardiovascular risk; unfortunately, CPET is not readily accessible to people post stroke. The objective of this study was to determine the utility of the 6-minute walk test (6MWT) as a less resource-intensive alternative to CPET for prescribing exercise intensity to people post stroke with motor impairments.


METHODS
Sixty participants (male, 71.7%; 13.5 ± 22.5 [mean ± standard deviation] months post stroke; age 64.5 ± 12.5 years, with a Chedoke-McMaster Stroke Assessment score of 4.9 ± .9 of the leg) underwent 6MWT, CPET, balance, strength, and cognition assessments.


RESULTS
6MWT heart rate (hr) was significantly lower than VAT-hr (92.3 ± 14.8 beats⋅min(-1) versus 99.8 ± 15.7 beats⋅min(-1), respectively, P < .001; correlation r = .7, P < .001). Bland-Altman analysis revealed that the 6MWT underestimated the VAT-hr by 7.7 ± 11.5%. The 95% confidence interval of the mean bias was large (14.8% and -30.3%), reflecting poor agreement, with 71.7% (n = 43) of the participants unable to reach a walking intensity at or above the VAT-hr. Lower oxygen uptake at the VAT (β = .655, P = .004), higher 6MWT-hr (β = 1.07, P = .01), and better balance (β = 1.128, P = .04) were associated with greater utility of the 6MWT for prescribing exercise.


CONCLUSIONS
The 6MWT-hr was not interchangeable with the target training VAT-hr determined by CPET. However, in combination with CPET, the 6MWT will indicate when deficits preclude walking alone as the primary exercise modality for optimizing cardiovascular fitness. Future studies to develop a less resource-intensive, multimodal alternative to the CPET for prescribing exercise are needed. A modality that minimizes the effect of stroke deficits, specifically poor balance, should be included.
Cardiovascular Prevention and Rehabilitation Program, Toronto Rehab/University Health Network, Toronto, Ontario, Canada. Electronic address: Susan.marzolini@uhn.ca.
Susan
S
Marzolini
Cardiovascular Prevention and Rehabilitation Program, Toronto Rehab/University Health Network, Toronto, Ontario, Canada; Canadian Partnership for Stroke Recovery, Ottawa, Ontario, Canada.
Paul
P
Oh
Canadian Partnership for Stroke Recovery, Ottawa, Ontario, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada.
Dale
D
Corbett
Cardiovascular Prevention and Rehabilitation Program, Toronto Rehab/University Health Network, Toronto, Ontario, Canada.
Daryl
D
Dooks
Cardiovascular Prevention and Rehabilitation Program, Toronto Rehab/University Health Network, Toronto, Ontario, Canada.
Marcella
M
Calouro
Canadian Partnership for Stroke Recovery, Ottawa, Ontario, Canada; Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
Bradley J
BJ
MacIntosh
Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada.
Rachel
R
Goodman
Canadian Partnership for Stroke Recovery, Ottawa, Ontario, Canada; Department of Physical Therapy, University of Toronto, Toronto, Ontario, Canada.
Dina
D
Brooks
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000072599:Cardiorespiratory Fitness / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009069:Movement Disorders / Q000209:etiology / Q000534:rehabilitation*; D010101:Oxygen Consumption / Q000502:physiology; D011446:Prospective Studies; D012044:Regression Analysis; D020521:Stroke / Q000150:complications; D000071939:Stroke Rehabilitation; D016896:Treatment Outcome; D016138:Walking / Q000502:physiology*
Exercise; rehabilitation; stroke care; stroke delivery; stroke recovery