Implementing blood flow restriction during high-intensity interval training enhances chronic adaptations in aerobic and muscular parameters, despite acutely accelerating fatigue during repeated sprints.
Systematic Review (n=244)
Does the addition of blood flow restriction to high-intensity interval training improve physiological adaptations in exercising subjects?
Adding blood flow restriction to high-intensity interval training may enhance aerobic, muscular, and anaerobic adaptations, though standardized protocols are needed.
BACKGROUND: The implementation of blood flow restriction (BFR) during exercise is becoming an increasingly useful adjunct method in both athletic and rehabilitative settings. Advantages in pairing BFR with training can be observed in two scenarios: (1) training at lower absolute intensities (e.g. walking) elicits adaptations akin to high-intensity sessions (e.g. running intervals); (2) when performing exercise at moderate to high intensities, higher physiological stimulus may be attained, leading to larger improvements in aerobic, anaerobic, and muscular parameters. The former has been well documented in recent systematic reviews, but consensus on BFR (concomitant or post-exercise) combined with high-intensity interval training (HIIT) protocols is not well established. Therefore, this systematic review evaluates the acute and chronic effects of BFR + HIIT. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to identify relevant studies. A systematic search on 1 February 2022, was conducted on four key databases: ScienceDirect, PubMed, Scopus and SPORTDiscus. Quality of each individual study was assessed using the Physiotherapy Evidence Database (PEDro) scale. Extraction of data from included studies was conducted using an adapted version of the 'Population, Intervention, Comparison, Outcome' (PICO) framework. RESULTS: A total of 208 articles were identified, 18 of which met inclusion criteria. Of the 18 BFR + HIIT studies (244 subjects), 1 reported both acute and chronic effects, 5 examined acute responses and 12 investigated chronic effects. Acutely, BFR challenges the metabolic processes (vascular and oxygenation responses) during high-intensity repeated sprint exercise-which accelerates central and peripheral neuromuscular fatigue mechanisms resulting in performance impairments. Analysis of the literature exploring the chronic effects of BFR + HIIT suggests that BFR does provide an additive physiological training stimulus to HIIT protocols, especially for measured aerobic, muscular, and, to some extent, anaerobic parameters. CONCLUSION: Presently, it appears that the addition of BFR into HIIT enhances physiological improvements in aerobic, muscular, and, to some extent, anaerobic performance. However due to large variability in permutations of BFR + HIIT methodologies, it is necessary for future research to explore and recommend standardised BFR guidelines for each HIIT exercise type.
Chua et al. (Fri,) conducted a systematic review in Healthy and active individuals (n=244). Blood flow restriction (BFR) combined with high-intensity interval training (HIIT) vs. High-intensity interval training without BFR was evaluated on Acute and chronic physiological and performance adaptations (aerobic, anaerobic, and muscular). Implementing blood flow restriction during high-intensity interval training enhances chronic adaptations in aerobic and muscular parameters, despite acutely accelerating fatigue during repeated sprints.