Effects of Cool Down on Muscle Blood Flow after High-Intensity Exercise: A Magnetic Resonance Imaging Study
【Supercategory：7. DESCENTE SPORTS SCIENCE Subcategory：7.44 Vol.44】
ABSTRACT
This study aimed to noninvasively image blood flow in the active limb using magnetic resonance imaging（MRI） and to measure blood flow recovery after maximal voluntary muscle contractions. Twenty healthy adult male subjects （21±1 years of age） underwent arterial spin labeling （ASL） to map blood flow in the proximal right forearm. Subjects performed 2 minutes of maximum intensity handgrip exercise in the MRI gantry. MRI imaging was performed three times: baseline, immediately after exercise, and 20 minutes after exercise. The obtained images were divided into the whole forearm, wrist flexor and extensor muscle groups, and radial bone, respectively. The signal intensity of the ASL was determined in each area. The three-dimensional（x,y-t） data were analyzed by combining the two-dimensional blood flow map with the time. Compared to the baseline level, blood flow in the whole forearm, wrist flexor and extensor muscles increased 1.4±0.2, 2.7±1.0 and 2.1±0.6 times; however, radial bone blood flow decreased 13 % on average immediately after 2 minutes of maximum intensity grip exercis. The whole forearm, extensor and flexor muscle blood flow measured 20 min after handgrip exercise returned to the baseline level; however, radial bone blood flow was significantly higher than the baseline level. These results suggest heterogeneity in the recovery of blood flow after maximal-intensity handgrip exercise among different tissues.
DECENTE SPORTS SCIENCE Vol.44/The DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE
This study aimed to noninvasively image blood flow in the active limb using magnetic resonance imaging（MRI） and to measure blood flow recovery after maximal voluntary muscle contractions. Twenty healthy adult male subjects （21±1 years of age） underwent arterial spin labeling （ASL） to map blood flow in the proximal right forearm. Subjects performed 2 minutes of maximum intensity handgrip exercise in the MRI gantry. MRI imaging was performed three times: baseline, immediately after exercise, and 20 minutes after exercise. The obtained images were divided into the whole forearm, wrist flexor and extensor muscle groups, and radial bone, respectively. The signal intensity of the ASL was determined in each area. The three-dimensional（x,y-t） data were analyzed by combining the two-dimensional blood flow map with the time. Compared to the baseline level, blood flow in the whole forearm, wrist flexor and extensor muscles increased 1.4±0.2, 2.7±1.0 and 2.1±0.6 times; however, radial bone blood flow decreased 13 % on average immediately after 2 minutes of maximum intensity grip exercis. The whole forearm, extensor and flexor muscle blood flow measured 20 min after handgrip exercise returned to the baseline level; however, radial bone blood flow was significantly higher than the baseline level. These results suggest heterogeneity in the recovery of blood flow after maximal-intensity handgrip exercise among different tissues.
DECENTE SPORTS SCIENCE Vol.44/The DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE
| Researcher | Kazuki Hotta*1, Naoki Kodama*2, Shinichiro Morishita*3, Atsuhiro Tsubaki*2 |
|---|---|
| University or institution | *1 Kitasato University, *2 Niigata University of Health and Welfare, *3 Fukushima Medical University |
Keywords
magnetic resonance imaging, arterial spin labeling, handgrip, skeletal muscle blood flow, bone blood flow