TY - JOUR
T1 - Quadriceps muscle blood flow and oxygen availability during repetitive bouts of isometric exercise in simulated sailing
AU - Vogiatzis, Ioannis
AU - Andrianopoulos, Vasileios
AU - Louvaris, Zafeiris
AU - Cherouveim, Evgenia
AU - Spetsioti, Stavroula
AU - Vasilopoulou, Maroula
AU - Athanasopoulos, Dimitrios
PY - 2011/7/1
Y1 - 2011/7/1
N2 - In this study, we wished to determine whether the observed reduction in quadriceps muscle oxygen availability, reported during repetitive bouts of isometric exercise in simulated sailing efforts (i.e. hiking), is because of restricted muscle blood flow. Six national-squad Laser sailors initially performed three successive 3-min hiking bouts followed by three successive 3- min cycling tests sustained at constant intensities reproducing the cardiac output recorded during each of the three hiking bouts. The blood flow index (BFI) was determined from assessment of the vastus lateralis using near-infrared spectroscopy in association with the light-absorbing tracer indocyanine green dye, while cardiac output was determined from impedance cardiography. At equivalent cardiac outputs (ranging from 10.3±0.5 to 14.8±0.86 L · min-1), the increase from baseline in vastus lateralis BFI across the three hiking bouts (from 1.1±0.2 to 3.1±0.6 nM · s-1) was lower (P = 0.036) than that seen during the three cycling bouts (from 1.1±0.2 to 7.2+1.4 μM · s-1) (Cohen's d: 3.80 nM · s-1), whereas the increase from baseline in deoxygenated haemoglobin (by ~17.0±2.9 μM) (an index of tissue oxygen extraction) was greater (P = 0.006) during hiking than cycling (by ~5.3±2.7 μM) (Cohen's d: 4.17 μM). The results suggest that reduced vastus lateralis muscle oxygen availability during hiking arises from restricted muscle blood flow in the isometrically acting quadriceps muscles.
AB - In this study, we wished to determine whether the observed reduction in quadriceps muscle oxygen availability, reported during repetitive bouts of isometric exercise in simulated sailing efforts (i.e. hiking), is because of restricted muscle blood flow. Six national-squad Laser sailors initially performed three successive 3-min hiking bouts followed by three successive 3- min cycling tests sustained at constant intensities reproducing the cardiac output recorded during each of the three hiking bouts. The blood flow index (BFI) was determined from assessment of the vastus lateralis using near-infrared spectroscopy in association with the light-absorbing tracer indocyanine green dye, while cardiac output was determined from impedance cardiography. At equivalent cardiac outputs (ranging from 10.3±0.5 to 14.8±0.86 L · min-1), the increase from baseline in vastus lateralis BFI across the three hiking bouts (from 1.1±0.2 to 3.1±0.6 nM · s-1) was lower (P = 0.036) than that seen during the three cycling bouts (from 1.1±0.2 to 7.2+1.4 μM · s-1) (Cohen's d: 3.80 nM · s-1), whereas the increase from baseline in deoxygenated haemoglobin (by ~17.0±2.9 μM) (an index of tissue oxygen extraction) was greater (P = 0.006) during hiking than cycling (by ~5.3±2.7 μM) (Cohen's d: 4.17 μM). The results suggest that reduced vastus lateralis muscle oxygen availability during hiking arises from restricted muscle blood flow in the isometrically acting quadriceps muscles.
KW - Muscle blood flow
KW - Near-infrared spectroscopy
KW - Sailing
UR - http://www.scopus.com/inward/record.url?scp=79960858280&partnerID=8YFLogxK
U2 - 10.1080/02640414.2011.574720
DO - 10.1080/02640414.2011.574720
M3 - Article
C2 - 21590577
AN - SCOPUS:79960858280
SN - 0264-0414
VL - 29
SP - 1041
EP - 1049
JO - Journal of Sports Sciences
JF - Journal of Sports Sciences
IS - 10
ER -