Effect of hyperoxia and hypoxia on leg blood flow and pulmonary and leg oxygen uptake at the onset of kicking exercise

1999 ◽  
Vol 78 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Maureen J MacDonald ◽  
Mark A Tarnopolsky ◽  
Richard L Hughson
Keyword(s):  
Blood Flow ◽  
Oxygen Uptake ◽  
Femoral Vein ◽  
Hypoxic Condition ◽  
Moderate Intensity ◽  
Exercise Time ◽  
Leg Blood Flow ◽  
Physiological Adaptations ◽  
Exercise Transitions ◽  
Echo Doppler Ultrasound

The purpose of this study was to examine the interactions of adaptations in O2 transport and utilization under conditions of altered arterial O2 content (CaO2), during rest to exercise transitions. Simultaneous measures of alveolar ([Formula: see text]O2alv) and leg ([Formula: see text]O2mus) oxygen uptake and leg blood flow (LBF) responses were obtained in normoxic (FiO2 (inspired fraction of O2) = 0.21), hypoxic (FiO2 = 0.14), and hyperoxic (FiO2 = 0.70) gas breathing conditions. Six healthy subjects performed transitions in leg kicking exercise from rest to 48 ± 3 W. LBF was measured continuously with pulsed and echo Doppler ultrasound methods, [Formula: see text]O2alv was measured breath-by-breath at the mouth and [Formula: see text]O2mus was determined from LBF and radial artery and femoral vein blood samples. Even though hypoxia reduced CaO2 to 175.9 ± 5.0 from 193.2 ± 5.0 mL/L in normoxia, and hyperoxia increased CaO2 to 205.5 ± 4.1 mL/L, there were no differences in the absolute values of [Formula: see text]O2alv or [Formula: see text]O2mus across gas conditions at any of the rest or exercise time points. A reduction in leg O2 delivery in hypoxia at the onset of exercise was compensated by a nonsignificant increase in O2 extraction and later by small increases in LBF to maintain [Formula: see text]O2mus. The dynamic response of [Formula: see text]O2alv was slower in the hypoxic condition; however, hyperoxia did not affect the responses of oxygen delivery or uptake at the onset of moderate intensity leg kicking exercise. The finding of similar [Formula: see text]O2mus responses at the onset of exercise for all gas conditions demonstrated that physiological adaptations in LBF and O2 extraction were possible, to counter significant alterations in CaO2. These results show the importance of the interplay between O2 supply and O2 utilization mechanisms in meeting the challenge provided by small alterations in O2 content at the onset of this submaximal exercise task.

Leg Blood Flow during Exercise in Man

1971 ◽  
Vol 41 (5) ◽  
pp. 459-473 ◽  
Author(s):  
L. Jorfeldt ◽  
J. Wahren
Keyword(s):  
Blood Flow ◽  
Oxygen Uptake ◽  
Femoral Vein ◽  
Mechanical Efficiency ◽  
Bicycle Ergometer ◽  
Work Intensity ◽  
Pulmonary Oxygen Uptake ◽  
Leg Blood Flow ◽  
Linear Relationships ◽  
Oxygen Difference

1. An indicator-dilution technique was used to determine human leg blood flow at rest and during exercise. The method is based on the infusion of Indocyanine Green into the femoral artery with blood sampling from the femoral vein at the level of the inguinal ligament. Evidence for mixing of dye and blood is presented, based on the finding of equal dye concentrations at two different sampling levels in the femoral vein. The minimum time of infusion required for equilibration at rest is 3 min and during exercise 1 min 20 s. 2. Leg blood flow was measured in eight healthy athletic subjects at rest and during upright exercise on a bicycle ergometer at 400, 800 and 1200 kpm/min. Linear relationships were found between blood flow on the one hand and work intensity and pulmonary oxygen uptake on the other. 3. Leg oxygen uptake was measured as the product of blood flow and femoral arterio-venous oxygen difference. Linear regressions were found for leg oxygen uptake in relation to both work intensity and pulmonary oxygen uptake. Leg mechanical efficiency during exercise averaged 34%. 4. A formula for the approximate calculation of leg blood flow is suggested, based on the pulmonary oxygen uptake and the femoral arterio-venous oxygen difference.

Exercise training enhances leg vasodilatory capacity of 65-yr-old men and women

1990 ◽  
Vol 69 (5) ◽  
pp. 1804-1809 ◽  
Author(s):  
W. H. Martin ◽  
W. M. Kohrt ◽  
M. T. Malley ◽  
E. Korte ◽  
S. Stoltz
Keyword(s):  
Blood Flow ◽  
Body Weight ◽  
Exercise Training ◽  
Oxygen Uptake ◽  
Endurance Exercise ◽  
Maximal Oxygen Uptake ◽  
Statistical Significance ◽  
Tissue Loss ◽  
Leg Blood Flow ◽  
Endurance Exercise Training

To determine whether extremity vasodilatory capacity may be augmented in older persons by endurance exercise training, lower leg blood flow and conductance were characterized plethysmographically at rest and during maximal hyperemia in 9 men and 10 women aged 64 +/- 3 (SD) yr before and after 31 +/- 6 wk of walking and jogging at 70-90% of maximal oxygen uptake for 45 min 3-5 days/wk. Maximal oxygen uptake expressed as milliliters per kilogram per minute improved 25% in men and 21% in women (P less than 0.01). Maximal leg blood flow and conductance increased in all nine men by an average of 39 +/- 33 (P less than 0.001) and 42 +/- 44% (P less than 0.004), respectively. Results were more variable in women and achieved unequivocal statistical significance only for maximal blood flow (+33 +/- 54% for blood flow and +29 +/- 55% for conductance; P less than 0.02 and P = 0.05, respectively). Body weight and skinfold adiposity declined in both sexes (P less than 0.05). Enhancement of vasodilatory capacity was related to weight loss in men and adipose tissue loss in women (r = 0.61 and 0.51, respectively; P less than 0.05). There were no significant changes in exercise capacity, body weight, or maximal blood flow in four male and three female controls aged 66 +/- 4 yr. Thus adaptability of the lower limb circulation to endurance exercise training is retained to at least age 65 yr.

Oxygen Uptake And Leg Blood Flow Kinetics And The Influence Of Exercise Training In Older Women

2007 ◽  
Vol 39 (Supplement) ◽  
pp. S359
Author(s):  
Liza Stathokostas ◽  
John M. Kowalchuk ◽  
Donald H. Paterson
Keyword(s):  
Blood Flow ◽  
Exercise Training ◽  
Oxygen Uptake ◽  
Older Women ◽  
Leg Blood Flow

Leg Blood Flow and Muscle Metabolism in Occlusive Arterial Disease of the Leg before and after Reconstructive Surgery

1975 ◽  
Vol 49 (3) ◽  
pp. 265-275 ◽  
Author(s):  
B. Pernow ◽  
B. Saltin ◽  
J. Wahren ◽  
R. Cronestrand ◽  
S. Ekeström
Keyword(s):  
Blood Flow ◽  
Oxygen Uptake ◽  
Reconstructive Surgery ◽  
Lactate Concentration ◽  
Creatine Phosphate ◽  
Arterial Disease ◽  
Thigh Muscle ◽  
Work Intensity ◽  
Leg Blood Flow ◽  
Occlusive Arterial Disease

1. Leg blood flow, uptake of oxygen and glucose and release of lactate by the leg and changes in intramuscular concentrations of metabolites were studied at rest and during exercise of increasing work loads in thirteen patients with occlusive disease of the iliac or superficial femoral arteries. 2. Leg blood flow (dye-dilution technique) and oxygen uptake during exercise were low and levelled with increasing work load. Considerable increases were noted in muscle lactate concentration and in the net release of lactate from the exercising leg. Muscle content (needle-biopsy technique) of ATP and creatine phosphate decreased during exercise, with an almost complete depletion of creatine phosphate in three patients. The decrease in muscle glycogen during work did not differ significantly from that of control subjects. 3. Repeated exercise after reconstructive surgery showed a considerable improvement in physical working capacity. Leg blood flow and oxygen uptake during exercise were significantly higher than before surgery and increased linearly in relation to work intensity. The decrease in creatine phosphate and lactate concentration of the thigh muscle during exercise was less pronounced and the release of lactate was lower than before vascular reconstruction. 4. It is suggested that the onset of the severe muscle symptoms during exercise in patients with occlusive arterial disease of the leg may be related to a low concentration of ATP and creatine phosphate in the affected muscles.

Reduced Oxygen Uptake During Steady State Exercise After 21-Day Mountain Climbing Expedition to 6,194 m

2001 ◽  
Vol 26 (2) ◽  
pp. 143-156 ◽  
Author(s):  
Maureen J. Macdonald ◽  
Howard J. Green ◽  
Heather L. Naylor ◽  
Christian Otto ◽  
Richard L. Hughson
Keyword(s):  
Blood Flow ◽  
Steady State ◽  
Oxygen Uptake ◽  
Respiratory Exchange Ratio ◽  
Submaximal Exercise ◽  
Metabolic Efficiency ◽  
Mountain Climbing ◽  
Leg Blood Flow ◽  
Exercise Onset ◽  
State Formula

We investigated the effect of a 21-day climbing expedition to 6,194 m on the oxygen uptake [Formula: see text] and leg blood flow (LBF) responses to submaximal exercise in five healthy, fit men during two-leg kicking exercise at 0-W and 50-W. Tests were completed 1 week before and 3 days after altitude acclimatization. The adaptation of [Formula: see text] at exercise onset was described by the time to 63% of the new steady state. Steady state [Formula: see text] during 50-W exercise was less post-climb (1290 ± 29 mL/min, mean ± SE) than pre-climb (1413 + 63 mL/min, P < .05). [Formula: see text] adapted more slowly at the onset of 50-W exercise post-climb. There were no differences in the steady state LBF during 50-W exercise, the increase above baseline, or the adaptation post-climb. Respiratory exchange ratio was greater at 50-W post-climb compared to pre-climb. Reduced steady state [Formula: see text] during exercise after exposure to high altitude is consistent with an increase in metabolic efficiency. Key words: work efficiency, leg blood flow, altitude, hypoxia, Doppler ultrasound

Determination of Leg Blood Flow During Exercise in Man: An Indicator-Dilution Technique Based on Femoral Venous Dye Infusion

1973 ◽  
Vol 45 (2) ◽  
pp. 135-146 ◽  
Author(s):  
J. Wahren ◽  
L. Jorfeldt
Keyword(s):  
Blood Flow ◽  
Healthy Subjects ◽  
Femoral Vein ◽  
Indicator Dilution ◽  
Dilution Method ◽  
Dilution Technique ◽  
Flow Measurements ◽  
Leg Blood Flow ◽  
Indicator Dilution Technique

1. A dye-dilution method has been developed for the determination of leg blood flow in man. The method is based on the infusion of indicator into the distal part of the femoral vein with blood sampling from the same vein at the level of the inguinal ligament. Catheterization of the femoral artery is not required. Evidence of adequate mixing of dye and blood is presented, based on the finding of the same dye concentration in samples from two different levels in the femoral vein. 2. Leg blood flow measured by this technique at rest and during exercise in six healthy subjects was found to agree closely with simultaneous determinations with an intra-arterial indicator-dilution technique. The reproducibility of the blood-flow measurements, expressed as the coefficient of variation for a single determination, was 9·8%. 3. A routine procedure is suggested for leg blood-flow determination based on femoral venous dye infusion. Using this procedure, leg blood flow was measured in twelve healthy subjects at rest and during exercise at work loads of 100, 200, 400 and 600 kpm/min. A linear relationship was found between leg blood flow and pulmonary oxygen uptake. 4. The applicability of this method to the study of patients with occlusive arterial disease of the leg is illustrated by findings in two patients before and after vascular reconstruction.

Sign in / Sign up

Export Citation Format

Share Document