We examined the effects of blood flow-restricted, low-intensity resistance exercise (termed kaatsu), using an elastic band for resistance, on muscle activation in patients with cardiovascular diseases. Six patients with cardiovascular diseases [male, 69±12 (SD) years old, five old myocardial infarction and one dilated cardiomyopathy] performed biceps flexion exercises (four sets) using an elastic band for resistance with blood flow restriction [BFR (kaatsu training)] or CON (unrestricted blood flow). During a BFR (kaatsu training) session, subjects wore a kaatsu belt inflated to 110-160 mmHg on the proximal region of both arms. Surface electromyography (EMG) was recorded from the biceps brachii muscles, and mean integrated EMG (iEMG) was analyzed. Ratings of perceived exertion (RPE) were measured using the Borg scale immediately after the last set of each exercise (Post). During exercises, muscle activation increased progressively under BFR (kaatsu training) (approximately 40%), but not under CON; muscle activation was higher under BFR (kaatsu training) than that under CON in all exercises (P < 0.001). RPE at Post was also higher (P < 0.05) under BFR (kaatsu training) than that under CON in all exercises. RPE at Post was significantly correlated with increased iEMG in biceps flexion exercises (r = 0.68, P < 0.001). We conclude that kaatsu training using elastic bands for resistance enhances muscle activation in patients with cardiovascular diseases and may be an effective method to promote muscle hypertrophy in patients with cardiovascular diseases.
[Objective] We explored KAATSU training performed in a pregnant woman was safe for the fetus at the third thrimester of pregnancy. [Methods] A 36-year-old primigravida woman underwent non-stress tests (NST) at 29 weeks and 6 days (29w6d) and 30w4d of gestation in three states: resting (no exercise load), biceps curls using a 1 kg load without restricted blood flow, and biceps curls under a 1 kg load with arm blood flow restriction (BFR) with KAATSU belts, a specially designed elastic pressure cuffs. In addition, maternal hemodynamics using a Task Force Monitor and umbilical artery resistance index (UARI) using pulse wave Doppler duplex system were measured during femoral BFR with KAATSU belts at 31w1d. [Results] All of NST results showed that the fetal status was considered to be good and appropriate for the gestational age. Although femoral BFR caused a reduction in the maternal preload, the UARI did not change. [Conclusion] Under the test conditions used in the present study, KAATSU training had no direct influence on the fetal status and utero-placental circulation. However, as the absence of fetal status influence of KAATSU training could not be confirmed, further investigation will be necessary.