title: Hemodynamic and hormonal responses to a short-term low-intensity resistance exercise with the reduction of muscle blood flow.
abstract: We investigated the hemodynamic and hormonal responses to a short-term low-intensity resistance exercise (STLIRE) with the reduction of muscle blood flow. Eleven untrained men performed bilateral leg extension exercise under the reduction of muscle blood flow of the proximal end of both legs pressure-applied by a specially designed belt (a banding pressure of 1.3 times higher than resting systolic blood pressure, 160-180 mmHg), named as Kaatsu. The intensity of STLIRE was 20% of one repetition maximum. The subjects performed 30 repetitions, and after a 20-seconds rest, they performed three sets again until exhaustion. The superficial femoral arterial blood flow and hemodynamic parameters were measured by using the ultrasound and impedance cardiography. Serum concentrations of growth hormone (GH), vascular endothelial growth factor (VEGF), noradrenaline (NE), insulin-like growth factor (IGF)-1, ghrelin, and lactate were also measured. Under the conditions with Kaatsu, the arterial flow was reduced to about 30% of the control. STLIRE with Kaatsu significantly increased GH (0.11+/-0.03 to 8.6+/-1.1 ng/ml, P < 0.01), IGF-1 (210+/-40 to 236+/-56 ng/ml, P < 0.01), and VEGF (41+/-13 to 103+/-38 pg/ml, P < 0.05). The increase in GH was related to neither NE nor lactate, but the increase in VEGF was related to that in lactate (r = 0.57, P < 0.05). Ghrelin did not change during the exercise. The maximal heart rate (HR) and blood pressure (BP) in STLIRE with Kaatsu were higher than that without Kaatsu. Stroke volume (SV) was lower due to the decrease of the venous return by Kaatsu, but, total peripheral resistance (TPR) did not change significantly. These results suggest that STLIRE with Kaatsu significantly stimulates the exercise-induced GH, IGF, and VEGF responses with the reduction of cardiac preload during exercise, which may become a unique method for rehabilitation in patients with cardiovascular diseases.
authors.affiliation: Department of Cardiovascular Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors.forename: Haruhito
authors.initials: H
authors.lastname: Takano
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Morita
authors.forename: Haruko
authors.initials: H
authors.lastname: Iida
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Asada
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Kato
authors.forename: Kansei
authors.initials: K
authors.lastname: Uno
authors.forename: Ken
authors.initials: K
authors.lastname: Hirose
authors.forename: Akihiro
authors.initials: A
authors.lastname: Matsumoto
authors.forename: Katsu
authors.initials: K
authors.lastname: Takenaka
authors.forename: Yasunobu
authors.initials: Y
authors.lastname: Hirata
authors.forename: Fumio
authors.initials: F
authors.lastname: Eto
authors.forename: Ryozo
authors.initials: R
authors.lastname: Nagai
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Sato
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Nakajima
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology*; D002302:Cardiac Output / Q000502:physiology; D013006:Growth Hormone / Q000097:blood; D006339:Heart Rate / Q000502:physiology; D006728:Hormones / Q000097:blood*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D042461:Vascular Endothelial Growth Factor A / Q000097:blood
chemical_list: D006728:Hormones; D042461:Vascular Endothelial Growth Factor A; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone