Related Experiment Video
Updated: Dec 6, 2025
A Rapidly Incremented Tethered-Swimming Maximal Protocol for Cardiorespiratory Assessment of Swimmers
Published on: January 28, 2020
Determining Maximal Tolerable Aerobic Training Intensity in the Acute Phase after Stroke: a Novel Dose Ranging Trial
Sharon F Kramer1, Toby Cumming2, Liam Johnson3
1Florey Institute of Neuroscience and Mental Health, University of Melbourne,245 Burgundy Street, 3084, Heidelberg, Victoria, Australia; NHMRC Centre of Research Excellence in Stroke Rehabilitation and Brain Recovery, 245 Burgundy Street, 3084, Heidelberg, Victoria, Australia.
Introduction:
There is strong evidence that cardiorespiratory fitness (CRF) training improves fitness and mobility after stroke. Despite the large number of studies, the most efficacious dose is yet to be determined. Furthermore, the safety of early post-stroke training, while theoretically beneficial, remains uncertain. The aim of this study is to determine the maximum safe and tolerable intensity of CRF training early post-stroke.
Methods:
This is a stratified (low to moderate exercise capacity), Phase I, 5+5 dose ranging trial protocol. Participants will be recruited within one month post-stroke and stratified by their exercise-capacity (i.e. low and moderate capacity). Cohorts of five participants will perform 12 interval-based training sessions for four-weeks at a pre-determined target-intensity. The intensity will increase in each consecutive cohort, in each stratum according to pre-defined rules until the maximum safe and tolerable intensity is reached, as determined by the occurrence of dose-limiting events and occurrence of adverse events. Dose-limiting events are defined as symptoms indicative of over-training including pain and inability to perform usual activities.
Study Outcome:
Maximum safe and tolerable intensity of CRF training in stroke survivors with low and moderate exercise capacity.
Discussion:
This study is a first step in the systematic development of a CRF training intervention. We believe similar dose ranging designs may be useful for development of other rehabilitation interventions in different study populations.
Related Concept Videos
01:17Exercise and Cardiac Output
Sustained exercise increases the muscles' oxygen demand, which can be...
01:22Cardiac Output II: Effect of Stroke Volume on Cardiac Output
Preload
Preload refers to the initial elongation of the cardiac myocytes before contraction and is related to the volume of blood filling the heart at the end of diastole, or end-diastolic volume. The...
01:20Exercise and Cardiovascular Response
Light to moderate physical activity initiates a series of interconnected responses in the body. The heart rate modestly increases in anticipation of the workout, followed by widespread vasodilation as oxygen consumption by skeletal muscles increases. This results in decreased peripheral resistance, increased capillary blood flow, and accelerated...
01:27Regulation of Stroke Volume
Preload refers to the degree of stretch on the heart before it contracts. It's analogous to the stretching of a rubber band; the more it's stretched, the more forcefully it snaps back. This concept is encapsulated in the Frank-Starling law of the...