|
|
|
|
JOURNAL
OF
SPORTS SCIENCE &
MEDICINE
|
 |
|
Research
article
|
METABOLIC AND CARDIOVASCULAR RESPONSES TO UPRIGHT CYCLE EXERCISE WITH LEG BLOOD FLOW REDUCTION |
|||||||||
Hayao Ozaki1, William F. Brechue2, Mikako Sakamaki1, Tomohiro Yasuda1, Masato Nishikawa3, Norikazu Aoki3, Futoshi Ogita3 and Takashi Abe1  |
|||||||||
1Department of Human and Engineered Environmental Studies, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Japan, 2Center for Physical Development Excellence, United States Military Academy, West Point, NY, USA, 3Department of Exercise Physiology, National Institute of Fitness and Sports in Kanoya, Kanoya, Japan |
|||||||||
|
|||||||||
© Journal of Sports Science and Medicine (2010) 9, 224 - 230 |
|||||||||
|
|
| ABSTRACT | |||
| The purpose of this study was to examine the metabolic and cardiovascular
response to exercise without (CON) or with (BFR) restricted blood flow to
the muscles. Ten young men performed upright cycle exercise at 20, 40, and
60% of maximal oxygen uptake, VO2max in both conditions while
metabolic and cardiovascular parameters were determined. Pre-exercise VO2
was not different between CON and BFR. Cardiac output (Q) was similar between
the two conditions as a 25% reduction in stroke volume (SV) observed in
BFR was associated with a 23% higher heart rate (HR) in BFR compared to
CON. As a result rate-pressure product (RPP) was higher in the BFR but there
was no difference in mean arterial pressure (MAP) or total peripheral resistance
(TPR). During exercise, VO2 tended to increase with BFR (~10%)
at each workload. Q increased in proportion to exercise intensity and there
were no differences between conditions. The increase in SV with exercise
was impaired during BFR; being ~20% lower in BFR at each workload. Both
HR and RPP were significantly greater at each workload with BFR. MAP and
TPR were greater with BFR at 40 and 60% VO2max. In conclusion,
the BFR employed impairs exercise SV but central cardiovascular function
is maintained by an increased HR. BFR appears to result in a greater energy
demand during continuous exercise between 20 and 60% of control VO2max;
probably indicated by a higher energy supply and RPP. When incorporating
BFR, HR and RPP may not be valid or reliable indicators of exercise intensity.
Key words: Aerobic exercise, doppler echocardiography, apparent exercise intensity, occlusion. |
|