title: Low-volume strength and endurance training prevent the decrease in exercise hyperemia induced by non-dominant forearm immobilization.
abstract: We examined the effect of 3-week upper limb immobilization on conduit artery cross-sectional area and peak hyperemia (BF(peak)) after exhaustive dynamic handgrip exercise (Ex(dyn)), and that of low-volume strength and endurance training during immobilization. Healthy volunteers (n = 21; mean age, 22 years) were divided into 3 groups: immobilization only (IMM; n = 7), immobilization with training (STR + END; n = 7), and control (no immobilization or training, CNT; n = 7). Endurance training comprised Ex(dyn) at 30% maximum voluntary contraction (MVC) (duration of each session, ~60 s; twice weekly). Strength training involved intermittent isometric handgrip exercise at 70% MVC (duration of each session, 40 s; twice weekly), repeated 10 times. We used ultrasound methods to measure the brachial artery cross-sectional area and the BF(peak) after Ex(dyn) for 5 min pre- and post-immobilization. We found a significant group by time interaction in BF(peak) (p < 0.05). A significant decrease was found in BF(peak) in the IMM (p < 0.05) between pre- and post-immobilization and a protective effect in the STR + END. The 3-week upper limb immobilization did not influence the baseline artery cross-sectional area. In conclusion, BF(peak) decreased after 3-week upper limb immobilization and a combination of strength training and endurance training preserved the blunted BF(peak).
authors.affiliation: National Institute of Fitness and Sports in Kanoya, 1 Shiromizu, Kanoya, Kagoshima, 891-2393, Japan.
authors.forename: Fumiko
authors.initials: F
authors.lastname: Ohmori
authors.forename: Takafumi
authors.initials: T
authors.lastname: Hamaoka
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Shiroishi
authors.forename: Takuya
authors.initials: T
authors.lastname: Osada
authors.forename: Norio
authors.initials: N
authors.lastname: Murase
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kurosawa
authors.forename: Shiro
authors.initials: S
authors.lastname: Ichimura
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Homma
authors.forename: Kazuki
authors.initials: K
authors.lastname: Esaki
authors.forename: Ryotaro
authors.initials: R
authors.lastname: Kime
authors.forename: Toshihito
authors.initials: T
authors.lastname: Katsumura
mesh_terms: D015444:Exercise / Q000502:physiology*; D005542:Forearm / Q000098:blood supply / Q000502:physiology; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology*; D007103:Immobilization / Q000379:methods*; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D010807:Physical Endurance / Q000502:physiology*; D055070:Resistance Training / Q000379:methods*; D055815:Young Adult