Table 3 Restriction of blood flow and BFR exercise while supine or using musculoskeletal unloading models

[75]

KAATSU (65 × 650-mm cuff, 50–100 mmHg, no muscle contractions, 10 min) following 24-h −6HDT bed rest

24 h of −6HDT bed rest resulted in ↓body mass,↓BV, ↓PV, and ↓IVCd; 10 min of 50 mmHg, KAATSU: ↑HR, ↓SV, ↓CO, ↓IVCd, ↔Hct, ↔Hb, ↔BV, and ↔PV. Authors suggest that KAATSU reproduces the effect of a gravity-like stress during simulated weightlessness

One subject developed neurocirculatory presyncope 5 min after 100 mmHg KAATSU. There were no symptoms in the remaining seven subjects

[76]

KAATSU (65 × 650-mm cuff, 150–160 mmHg) with −6HDT leg press resistance exercise (30% 1RM, four sets, repetitons: 30/15/15/15, 1-min rest between sets) following 24-h −6HDT bed rest

24 h of −6DHT bed rest: ↓body mass, ↓BV, ↓PV, and ↑Hct. KAATSU + −6DHT leg press resistance exercise:↑HR, ↑BP, ↓SV, and ↑CO. Authors suggest that KAATSU with leg press exercise mimics the exercise hemodynamic response to exercise in 1-G

Potential conflict of interest between the KAATSU device and the journal publishing the research study

[77]

Supine with KAATSU (60 × 605 mm, 200 mmHg, no muscle contractions vs. standing)

Supine with KAATSU: ↓SV, ↑HR, ↑TPR, and ↓CO. Authors suggest that KAATSU induced hemodynamics similar to standing

Case study: potential conflict of interest between the KAATSU device and the journal publishing the research study. Fluid shift stimuli are not introduced

[123]

Supine with KAATSU (60 × 605 mm, 50–250 mmHg, no muscle contractions vs. standing)

Supine with KAATSU: ↑FVd, ↓FBf, ↓IVCd, ↓LVDd, ↓CO, ↑HR, and ↑TPR. Authors suggest that KAATSU induced hemodynamics similar to standing

Fluid shift stimuli are not introduced

[70]

BFR (60 × 830 mm, 150 mmHg) KEx resistance exercise (20% MVC, three sets, repetitons to fatigue 1.5-min rest between sets) during 30 days of unloading via ULLS

Following 30 days of ULLS: ↔KE CSA, ↑KE endurance, ↓PF CSA, ↓PF MVC, ↔IGF1, and ↔IGFBP3. Authors suggest that BFR exercise is effective in maintaining muscle size and strength and improving muscular endurance during unloading

Fluid shift stimuli are not introduced. ULLS model may not be appropriate for systemic blood markers

[124]

Restriction of blood flow (77 × 770 mm, 200 mmHg, five sets, 5-min bouts, 3-min rest between sets during 14 days of cast immobilization

Restriction of blood flow: ↔KE MVC, ↔PF CON60,↔leg/thigh CIRC, and ↔GH. Authors suggest that restriction of blood flow to the lower extremity prevents disuse muscular weakness

Fluid shift stimuli are not introduced. Cast immobilization model differs from spaceflight musculoskeletal unloading due to joint mobility