The feasibility, safety, and efficacy of upper limb garment-integrated blood flow restriction training in healthy adults

Abstract

Abstract Background Blood flow restriction training (BFR) has been demonstrated to increase muscle hypertrophy and strength, but has logistical and cost barriers. Garment-integrated BFR has the potential to reduce these barriers by lowering equipment demands and cost. The primary aim of the study was to explore the feasibility of garment-integrated BFR in the upper limb of healthy adults, with a secondary aim of exploring safety and efficacy. Methods Physically active and otherwise healthy participants with no previous experience with BFR were sought. Eligible participants completed a five-week garment-integrated BFR programme that involved completing two sessions per week. Feasibility was determined by a priori defined thresholds for recruitment, adherence to the garment-integrated BFR programme, and data collection. Safety was determined by recording adverse events and by monitoring for total arterial occlusion pressure using a fingertip pulse oximeter. Efficacy was determined by measuring push-ups to volitional failure, arm girth, and number of prescribed repetitions completed. Feasibility and safety outcomes were reported descriptively or as a proportion with associated 95% confidence intervals (95% CI). Mean change, 95% CIs, and associated effect sizes were calculated for efficacy outcomes. Results Twenty-eight participants were included (15 men, 13 women; mean age 31.6 years [±9.1]) and 27 successfully completed the study. Participants were successfully recruited within three months and 278/280 sessions were successfully completed (adherence=99.3%, 95% CI 97.4%, 99.9%). Minimal adverse events were reported; one incident of localised bruising (0.36%, 95% CI 0.06%, 2.0%) and three incidences of excessive pain during or post-exercise from two separate participants (1.07%, 95% CI 0.03%, 3.1%). 82/2240 pulse oximeter readings were not recorded (3.7%, 95% CI 2.9%, 4.5%). Mean push-ups to volitional failure increased by 40% (mean change=8.0, 95% CI 6, 10, d=1.40). Mean arm girth and number of prescribed repetitions completed were unchanged. Conclusions Garment-integrated BFR is feasible and has no signal of important harm in the upper limb of healthy adults, and could proceed to a future trial with stop/go criteria for randomisation. Further work is required to investigate the efficacy of garment-integrated BFR and determine its equivalence or superiority compared to existing BFR methods.

Keywords

• Safety
• Feasibility
• Blood flow restriction
• Kaatsu training
• Occlusion training
• BFR-integrated