Intensifying Functional Task Practice to Meet Aerobic Training Guidelines in Stroke Survivors

Abstract

Objective: To determine whether stroke survivors could maintain workloads during functional task practice that can reach moderate levels of cardiometabolic stress (i.e., ≥40% oxygen uptake reserve (trueV˙O2R) for ≥20 min) without the use of ergometer-based exercise.Design: Cross-sectional study using convenience sampling.Setting: Research laboratory in a tertiary rehabilitation hospital.Participants: Chronic hemiparetic stroke survivors (>6-months) who could provide consent and walk with or without assistance.Intervention: A single bout of intermittent functional training (IFT). The IFT protocol lasted 30 min and involved performing impairment specific multi-joint task-oriented movements structured into circuits lasting ~3 min and allowing 30–45 s recovery between circuits. The aim was to achieve an average heart rate (HR) 30-50 beats above resting without using traditional ergometer-based aerobic exercise.Outcome measures: Attainment of indicators for moderate intensity aerobic exercise. Oxygen uptake (trueV˙O2), carbon dioxide production (trueV˙CO2), and HR were recorded throughout the 30 min IFT protocol. Values were reported as percentage of trueV˙O2R, HR reserve (HRR) and HRR calculated from predicted maximum HR (HRRpred), which were determined from a prior maximal graded exercise test.Results: Ten (3-female) chronic (38 ± 33 months) stroke survivors (70% ischemic) with significant residual impairments (NIHSS: 3 ± 2) and a high prevalence of comorbid conditions (80% ≥ 1) participated. IFT significantly increased all measures of exercise intensity compared to resting levels: trueV˙O2 (Δ 820 ± 290 ml min−1, p < 0.001), HR (Δ 42 ± 14 bpm, p < 0.001), and energy expenditure (EE; Δ 4.0 ± 1.4 kcal min−1, p < 0.001). Also, mean values for percentage of trueV˙O2R (62 ± 19), HRR (55 ± 14), and HRRpred (52 ± 18) were significantly higher than the minimum threshold (40%) indicating achievement of moderate intensity aerobic exercise (p = 0.004, 0.016, and 0.043, respectively).Conclusion: Sufficient workloads to achieve moderate levels of cardiometabolic stress can be maintained in chronic stroke survivors using impairment-focused functional movements that are not dependent on ergometers or other specialized equipment.

Vigorous cool room treadmill training to improve walking ability in people with multiple sclerosis who use ambulatory assistive devices: a feasibility study

“…The oxygen uptake efficiency slope, a measure of the cardiorespiratory reserve, significantly increased at post, which was sustained during follow up (Table 3) [62,63]. In terms of indicators of achievement of a maximal GXT, four out of 10 participants achieved two or more criteria for test termination at pre, 3 out of 8 at post, and 3 out of 7 at follow up [46,47]. The maximal respiratory exchange ratio ranged from 0.84 to 1.28 (1.07 ± 0.15) at pre, 0.93 to 1.24 (1.07 ± 0.12) at post, and 0.90 to 1.21 (1.07 ± 0.11) at follow up, in which five out of 10 participants achieved respiratory exchange ratio more than 1.1 at pre, 4 out of 8 at post, and 3 out of 7 at follow up.…”

“…Fitness was assessed using maximal GXT on a seated recumbent stepper [46]. All participants were asked to exercise at increasingly difficult levels while wearing a facemask to measure how much oxygen they consumed (Moxus Metabolic Systems; AEI Technologies, Inc.).…”

“…A heart rate monitor was placed on their chest to measure maximal heart rate achieved during GXT. Participants were verbally encouraged to exercise as long as they could, and the workload was increased in~20-watt increments every 2 min, starting from load level 3 (21 watts) until exhaustion [46]. Participants were considered to have attained maximal oxygen consumption (V O 2 ) if at least two of the following criteria were met: (a) V O 2 plateau (no increase in V O 2 by 150 mL/min despite increasing workload) [46,47], (b) respiratory exchange ratio > 1.10 [47], (c) > 90% age-predicted maximal heart rate [47], and/or (d) > 8/10 rate of perceived exertion [47].…”

Vigorous cool room treadmill training to improve walking ability in people with Multiple Sclerosis who use ambulatory assistive devices: A feasibility study.

“…In terms of indicators of achievement of a maximal GXT, four out of 10 participants achieved two or more criteria for test termination at pre, 3 out of 8 at post, and 3 out of 7 at follow up (46,47 follow up, in which five out of 10 participants achieved more than 90% of their age-predicted maximal heart rate at pre, 4 out of 8 at post, and 4 out of 7 at follow up. Borg's rating of perceived exertion reported at the end of GXT ranged from 6.0 to 10.0 (9.2+1.5) at pre, 7.0 to 10.0 (9.5+1.1) at post, and 7.0 to 10.0 (9.6+1.1) at follow up, in which eight out of 10 participants rated more than 8.0 on Borg's rate of perceived exertion at pre, 7 out of 8 at post, and 6 out 7 at follow up.…”

Vigorous cool room treadmill training to improve walking ability in people with Multiple Sclerosis who use ambulatory assistive devices: A feasibility study.

“…A heart rate monitor was placed on their chest to measure maximal heart rate achieved during GXT. Participants were verbally encouraged to exercise as long as they could, and the workload was increased in ~20-watt increments every 2 minutes, starting from load level 3 (21 watts) until exhaustion (46). Participants were considered to have attained maximal oxygen consumption (VȮ 2 ) if at least two of the following criteria were met: (a) VȮ 2 plateau (no increase in VȮ 2 by 150 mL/min despite increasing workload) (46,47), (b) respiratory exchange ratio >1.10 (47), (c) >90% age-predicted maximal heart rate (47), and/or (d) >8/10 rate of perceived exertion (47).…”