Author(s): PRESTA, D., TAM, L., BERGDAHL, A., Institution: CONCORDIA UNIVERSITY, Country: CANADA, Abstract-ID: 345

INTRODUCTION:
KAATSU – Japanese for added pressure, is a mode of blood flow restriction that allows a pneumatic cuff to be inflated cyclically to induce circumferential pressure onto a proximal limb. This can allow more robust circulation in inflammatory markers – especially following exercise which can assist recovery and reduce muscle soreness. Furthermore, wearing KAATSU bands prior to exercise may enhance performance by pre-activating a localized “fight-or-flight” response in the muscles, increasing metabolic stress and hormonal signaling (e.g., growth hormone and IGF-1), which can prime the neuromuscular system. Post-COVID-19 syndrome is a chronic, multi-system condition consequential of an acute COVID-19 infection. A symptom of the disease is post-exertional malaise (PEM) which can limit functionality and induce severe fatigue. The goal of this study was to determine if individuals living with post-COVID-19 syndrome can have a stronger performance following 10-minutes of KAATSU before and after exertion, and if their PEM lessens.
METHODS:
Men and women (n=10) with a mean age of 46, who have been living with post-COVID-19 syndrome for at least one year were recruited to attend two exercise testing sessions. One of the visits, participants wore KAATSU bands at the proximal thighs before and after completing six exercise tests; wall sit (WS), 30s sit to stand (STS), grip strength (GS), 1 repetition max (RM) single leg press, 5-minute step test (ST) and the 6-minute walk test (MWT). At 24hours after both sessions, participants were asked to rate their PEM on a scale from 0 (no PEM) to 10 (extreme).
RESULTS:
Paired-sample correlations showed strong within-subject associations between conditions across all outcomes (r = .809–.988, all p ≤ .005), indicating high measurement consistency and stable individual ranking between trials. Paired t-tests revealed a significant difference in WS time with KAATSU outperforming control (mean difference = −18.4, 95% CI [−30.6, −6.2], t(9) = −3.41, p = .008). A trend toward improvement was observed for STS repetitions under KAATSU (mean difference = −1.9, p = .076), while no significant differences were found for GS, 6MWT and 1 RM dominant leg press. The rating of PEM on a scale from 0-10 averaged 4.2 following the CON and 2.5 following KAATSU.
CONCLUSION:
KAATSU produced improvements in WS time and trends toward better functional repetition performance while maintaining highly consistent strength and endurance outputs, suggesting enhanced function without disruption of movement control. Importantly, PEM ratings were lower following KAATSU (mean = 2.5) compared with control (mean = 4.2), indicating a trend toward improved exercise tolerance and recovery. For individuals living with long COVID, KAATSU may offer a low-load strategy to elicit physiological benefits while minimizing symptom exacerbation.