Effects Of 6-week Kaatsu Walking Training On Limb Venous Compliance In Elderly Subjects

Abstract

Venous compliance declines with age and improves with chronic endurance exercise. KAATSU-walking is a unique training method for promoting muscle hypertrophy and strength gains under the conditions with restricted venous blood flow, and inducing venous pooling of blood, which may affect limb venous compliance. However, the effects of KAATSU training on venous properties have not been investigated. PURPOSE: This study investigated the influence of a 6-week-walk training combined with KAATSU on venous properties in older men and women. METHODS: Twenty-two elderly men and women, aged 60-78 years, were randomized into either a KAATSU-walk training group (n=11, KAATSU-walk) or a non-exercising control group (n=11, Control). The KAATSU-walk group performed 20 min treadmill walking (67 m/min), five days/wk for 6 wk. A non-exercising group was advised to perform daily slow walk for 20 min five days/wk during the study. Before (pre) and after (post) 6 wk, strain gauge venous occlusion pletysmography was used to assess limb venous vascular properties. Venous volume variation (VVV) was defined as the maximal relative volume increase in the limb at a certain cuff pressure, and VVV at different occlusion pressures represents the pressure-volume curve. Compliance was derived from the slope of the pressure-volume curve. Venous emptying rate was calculated as the slope of the tangent at the curve 0.5 s after cuff release. The time 0.5 s after cuff deflation was chosen to avoid any cuff artifact, and the effective pressure of the cuff on the venous system at 0.5 s was calculated by using the pressure-volume curve. RESULTS: Leg venous compliance was significantly increased in KAATSU-walk group (pre 0.066±0.004 ml·100ml-1·mmHg-1, post 0.078±0.007, P<0.05), compared with control group (pre 0.069±0.008; post 0.068±0.04). Leg venous flow resistance decreased (pre 1.31±0.1 mmHg·ml-1·100 ml·min; post 1.08±0.08) in KAATSU-walk group, compared with control group (pre 1.23±0.12; post 1.38±0.07). In contrast, arm compliance did not change significantly in KAATSU-walk and control group. CONCLUSIONS: The present study provides the first evidence that daily KAATSU-walk may be a unique and novel training for improving limb venous compliance in untrained older subjects.