Muscle size and strength are increased following walk training with restricted venous blood flow from the leg muscle, Kaatsu-walk training

Abstract

Previous studies have shown that low-intensity resistance training with restricted muscular venous blood flow (Kaatsu) causes muscle hypertrophy and strength gain. To investigate the effects of daily physical activity combined with Kaatsu, we examined the acute and chronic effects of walk training with and without Kaatsu on MRI-measured muscle size and maximum dynamic (one repetition maximum) and isometric strength, along with blood hormonal parameters. Nine men performed Kaatsu-walk training, and nine men performed walk training alone (control-walk). Training was conducted two times a day, 6 days/wk, for 3 wk using five sets of 2-min bouts (treadmill speed at 50 m/min), with a 1-min rest between bouts. Mean oxygen uptake during Kaatsu-walk and control-walk exercise was 19.5 (SD 3.6) and 17.2 % (SD 3.1) of treadmill-determined maximum oxygen uptake, respectively. Serum growth hormone was elevated (P < 0.01) after acute Kaatsu-walk exercise but not in control-walk exercise. MRI-measured thigh muscle cross-sectional area and muscle volume increased by 4-7%, and one repetition maximum and maximum isometric strength increased by 8-10% in the Kaatsu-walk group. There was no change in muscle size and dynamic and isometric strength in the control-walk group. Indicators of muscle damage (creatine kinase and myoglobin) and resting anabolic hormones did not change in both groups. The results suggest that the combination of leg muscle blood flow restriction with slow-walk training induces muscle hypertrophy and strength gain, despite the minimal level of exercise intensity. Kaatsu-walk training may be a potentially useful method for promoting muscle hypertrophy, covering a wide range of the population, including the frail and elderly.

Physiological stimuli necessary for muscle hypertrophy

“…The CSA of the thigh muscle and strength significantly increased only for the BFR group. Considering the conventional findings of the walking study, showing that older adults and about a 6-month period are requirements for observing hypertrophy, the findings of Abe et al (2006) clearly demonstrated the potential of BFR. Not surprisingly, 6-10 weeks of walk training with BFR was effective in increasing muscle size for older adults 52,53) .…”

“…One reason for the absence of the hypertrophic effect in young adults is that these studies employed overly short training periods (3 weeks) [58][59][60] . A further explanation could be that young adults tend to be active and strong compared to older adults, so that walking does not turn out to be a sufficient exercise stimulus for hypertrophy.…”

“…By taking advantage of BFR, it is plausible that the hypertrophic effect of cycle or walk training can be augmented, and thus the program period required until significant hypertrophy occurs can be shortened. Abe et al (2006) compared the effect of walking with and without BFR on muscle size and strength 59) , in young men. The exercise consisted of 5 sets of 2 min walking (treadmill speed at 50 m/min), with 1 min rest between sets, which was undertaken twice a day, 6 days per week, for 3 weeks.…”

Effect of KAATSU training on a patient with benign fasciculation syndrome

“…Aging has often been associated with hyposecretion of growth hormone (GH), and GH hyposecretion has been associated with muscle atrophy and depressive symptoms, thereby affecting patients QOL (Hull and Harvey, 2003). Although it is unclear how KAATSU exercise induces enhanced muscle strength and the mechanism of myopachynsis, it has been shown that a significant increase in GH level is observed immediately after KAATSU exercise (Takarada et al, 2000a;Takano et al, 2005;Abe et al, 2006). This observation indicates the possible involvement of increased GH level in the mechanism of myopachynsis in BFS patients.…”

“…For treatment, exercise therapy may be performed, but no effective rehabilitation program has been established. KAATSU exercise, a novel, attention-drawing method of low-intensity resistance exercise performed under the condition of restricting muscle blood flow (Takarada et al, 2000b;Abe et al, 2006;Karabulut et al, 2007;Wernbom et al, 2008), causes minimal strain on the musculoskeletal and cardiovascular systems compared to high-intensity resistance exercise and thus is increasingly applied to rehabilitation programs for patients with various disorders. Meanwhile, its effect on BFS patients has yet to be examined.…”