Low-volume
strength and endurance training preserves immobilization-induced impairment in
hyperemic response to exhaustive dynamic grip exercise
Fumiko
Ohmori1,
Takafumi Hamaoka1,
Kiyoshi Shiroishi2,
Takuya Osada3,
Norio Murase3),
Ryotaro Kime3,
Yuko Kurosawa4,
Shiro Ichimura5,
Toshiyuki Homma6,
Mika Matsumura7,
Kazuki Esaki3,
Kuniko Yamaguchi8, and
Toshihito Katsumura3
1National
Institute of Fitness and Sports in Kanoya; 2Department of Judotherapy and Sports Medicine,
Faculty of Health Science, Ryotokuji University; 3Department
of Sports Medicine for Health Promotion, Tokyo Medical University; 4Department of Neurology,
University of Cincinnati; 5Faculty of Science and Technology, Tokyo
University of Science; 6Department of sports Science, Japan
Institute of Sports Sciences; 7Department of Pediatrics, Tokyo Medical
University; 8Yamanashi Gakuin Junior Coll
This study aimed at examining the effect of 3-week upper limb
immobilization on the structure of the conduit artery and hyperemic response (BFhyp) to exhaustive dynamic handgrip exercise (Exdyn)
and the effect of low-volume strength and/or
endurance training during immobilization.
Healthy young volunteers were placed into immobilization only
(IMM), immobilization with strength training (STR), immobilization with
endurance training (ETR), and immobilization with both endurance and strength
training of twice weekly (STR+ETR) and control (CNT). Endurance training comprised Exdyn
at 30% maximum voluntary contraction (MVC) at
a rate of 1 repetition per 1 second.
Strength training comprised an isometric handgrip exercise at 70% MVC
for 2 seconds with a 2-second rest interval, repeated 10 times. We measured the brachial artery
diameter, blood flow at resting baseline and BFhyp after Exdyn
for 5 minutes using ultrasound methods pre- and post-immobilization. There was no significant difference
between pre- and post-immobilization in any parameters at resting
baseline. Two-way ANOVA shows a
significant interaction (group * pre-post) in BFhyp
(p<0.05). The post-hoc
comparison denotes a significant difference in BFhyp between CNT and
IMM, STR, and STR+ETR, between IMM and both ETR and STR+ETR. In conclusion, the 3-week upper limb immobilization did not influence baseline structure
of the artery but decreased BFhyp.
During immobilization, strength training did not prevent the blunt BFhp, endurance training alone preserved BFhyp, and dual training increased BFhyp.
Key
words: immobilization, endurance training, strength training