Table 2. A literature review of various studies providing evidence regarding the efficacy of HIIT in clinical outcomes of cerebrovascular disease patients.

AIH: acute intermittent hypoxia; AV O2: arteriovenous oxygen difference; BBS: Berg balance scale; BDNF: brain-derived neurotrophic factor; DGI: dynamic gait index; EQ-5D: EuroQol 5 Dimension; FIM: functional independence measure; HIGT: high-intensity gait training; HIIT: high-intensity interval training; HR: heart rate; MICT: moderate-intensity continuous training; NIHSS: National Institutes of Health Stroke Scale; RCT: randomized control trial; TMT-B: Trail Making Test-B; VO2: oxygen consumption

Author	Study Type	Study Population	Sample Size	HIIT Protocol	Control	Outcomes	Results	Conclusion
Boyne et al. [29] 2015 USA	Randomized crossover trial	Ambulatory persons with chronic stroke of more than 6 months.	19	30-second fast walking on a treadmill at max tolerated speed with varying rest periods of 30s, 60s, and 120s.	None specified	V̇O2 peak, Exercise tolerance, HR, peak treadmill speed, total step count	The P30 group got the highest mean VO2 at 70.9% VO2peak and 1,619 steps, but lower exercise tolerance than P60 or P120; P60 showed balanced results.	Combining P30 and P60 in HIIT could optimize treadmill speed, aerobic intensity, and stepping frequency, potentially enhancing gait and aerobic capacity.
Nepveu et al. [30] 2017 Canada	RCT trial	Patients with chronic stroke	22	High-intensity interval training (15 minutes) after motor task practice	Non-exercise control	Motor skill retention, neuroplasticity measures (corticospinal excitability)	HIIT improved motor skill retention compared to controls, with modest neuroplastic changes observed in participants.	One HIIT session after motor practice improved skill retention and potentially accelerated recovery in stroke patients.
Parreiras et al. [31] 2019 Brazil	Double-blind randomized trial	Stroke patients with weakness of respiratory muscle (N=38)	38	Home-based, high-intensity home respiratory muscle training, 40 minutes daily for 8 weeks, progressed weekly	Similar design but a sham intervention.	Primary: Strength of Inspiratory muscle; Secondary: Strength of expiratory muscle, walking capacity, inspiratory endurance.	Increased inspiratory strength by 27 cmH2O and expiratory strength by 42 cmH2O, reduced dyspnea by 1.3 points post-training, but no differences in respiratory complications or walking capacity.	Home-based high-intensity respiratory muscle training effectively improves respiratory strength and reduces dyspnea in chronic stroke patients.
Tong et al. [32] 2019 China	Pilot trial (RCT)	Mild-moderate ischemic stroke within 24 hours.	300	Early Routine Mobilization: < 1.5 h/d (24-48 h); Early Intensive Mobilization: ≥3 h/d (24-48 h); Very Early Intensive Mobilization: ≥3 h/d (< 24 h)	Standard care according to guidelines	Modified Rankin Scale score (0-2) at 3 months follow-up	The Early Intensive Mobilization group showed 53.5% favorable outcomes compared to 37.8% in the Very Early Intensive Mobilization group, indicating better rehabilitation effectiveness at 24-48 hours post-stroke.	High-intensity physical rehabilitation should commence 48 hours after a stroke for potential benefits. Very Early Intensive Mobilization has no favorable outcomes at 3 months.
Soh et al. [33] 2020 South Korea	Single-blinded RCT	Patients after minor stroke (NIHSS ≤3)	36	Lateral push-off skater exercise, 30 min, 3x per week for 12 weeks	Conventional treadmill training	EQ-5D, VO2peak, minute ventilation, Berg Balance Scale (BBS), Dynamic Gait Index (DGI),	Significant improvements in EQ-5D, VO2peak, oxygen pulse, minute ventilation, DGI, and BBS in the study group (P<.05)	Skater exercise significantly improves cardiorespiratory fitness, health-related quality of life, and balance, and is recommended for minor stroke patients.
Hsu et al. [34] 2021 Taiwan	RCT trial	Stroke patients (age ~55, stroke duration >24 months)	23	High-intensity interval training (HIIT) at 80% followed by 40% of VO2peak in alternate cycle	MICT at 60% of VO2peak for 36 sessions of 30 minutes each	VO2peak, CO, AV O2difference, cerebral oxygenation (Δ[O2Hb], Δ[HHb], Δ[THb]), BDNF levels, neuron morphology	HIIT significantly increased VO2peak by 20.7% (compared to 9.8% for MICT), cardiac output, Δ[HHb], Δ[THb], and serum BDNF levels, while also enhancing neurite percentage.	HIIT is more effective than MICT in improving aerobic capacity, cerebral oxygen utilization, serum BDNF levels, and neuronal activities in stroke patients.
Tor Ivar Gjellesvik et al. [14] 2021 Norway	Multicenter RCT	Adult stroke survivors (3 months to 5 years post-stroke)	70	4×4 minutes of HIIT by treadmill at 85%-95% of peak HR combined with standard care	Standard care alone	Physical, mental, and cognitive functioning are assessed using various tests (FIM and Stroke Impact Scale).	Significant enhancements in BBS, 6-minute walk test, and executive function (TMT-B) immediately after HIIT and after 12 months	HIIT combined with standard care significantly improves physical and cognitive function post-stroke, with lasting effects on executive function.
Krawcyk et al. [35] 2023 Denmark	Post-intervention follow-up RCT	Patients having a lacunar stroke	71	Home-based HIIT for three months with weekly motivational calls	Usual care	Cardiorespiratory fitness, physical activity, cognition, and mental well-being and recurrent stroke.	No change in cardiorespiratory fitness; increased vigorous-intensity activity post-intervention; similar recurrent stroke rates (n=3) in both groups.	With early HIIT, long-term cardiorespiratory fitness did not show significant improvement but increased post-stroke vigorous activity. Motivation is crucial for long-term physical activity.
Moncion et al. [36] 2024 Canada	Multi-site RCT	Individuals ≥6 months post-stroke	82	10×1-minute intervals at 80%-100% HRR interspersed with 1 minute at 30% HRR	MICT	Cardiovascular risk factors, V̇O2peak, mobility parameters (10 m gait speed, 6-minute walk test)	After 12 weeks, the HIIT group showed greater V̇O2peak gains (3.52 mL/kg·min) than MICT group (1.71 mL/kg·min), with no adverse events.	Short-interval HIIT may effectively improve V̇O2peak compared to MICT after 12 weeks, offering better cardiovascular fitness.
Hornby et al. [37] 2024 USA	Randomized crossover trial, Phase II	Chronic stroke patients (>6 months post-stroke)	35	AIH combined with HIGT for up to 15 sessions; AIH involved cycles of hypoxia (8%-9% O2) and normoxia (21% O2) before HIGT	Normoxia before HIIT	Peak treadmill speed, fastest speed, self-selected speed, 6-minute walk test,	AIH + HIGT: greater improvements in self-selected (0.14 m/s), fastest (0.16 m/s), peak treadmill speed (0.21 m/s), & spatiotemporal symmetry compared to normoxia + HIGT (P<0.01).	The combination of AIH and HIT significantly enhanced locomotor function compared to normoxia plus HIT, highlighting its potential to improve rehabilitation outcomes for stroke patients.