PubMed Health⌕ Search

Biomedical subjects

D Eager

Publications and source records attributed to D Eager.

4 recordsLinked to original sources
PubMed1983

Prolonged exercise in highly trained female endurance runners.

The effects of prolonged exercise in a 21 degree C dry bulb and 15 degree C wet bulb environment at 65%-70% VO2max were examined in seven highly trained females. The subjects, aged 22-35 years, underwent an initial incremental treadmill test to exhaustion, with assessment of VO2max and related cardiorespiratory variables. One week later, under similar environmental conditions, subjects ran at approximately 65% VO2max for 80 min on a motor-driven treadmill. Approximately 10 ml of venous blood was withdrawn 10 min prior and immediately prior to the onset of prolonged exercise, and at 20, 40, 60, and 80 min, and 20 min post-exercise. Venous blood was analyzed for glucose, lactate, osmolality, Na+, K+, protein, and hemoglobin (Hb). Hematocrit was measured and changes in plasma volume calculated. VO2, VE, respiratory exchange ratio, and heart rate were recorded at 17, 37, and 77 min. The percent body fat estimated from skinfold thicknesses was 19 +/- 1%. The mean VO2max was 59.3 +/- 1.0 ml . kg-1 . min-1, with a mean max VE STPD and heart rate of 78.75 +/- 3.10 1 . min-1 and 175 +/- 4 beats . min-1, respectively. No significant changes occurred in VO2, VE, % VO2max, heart rate, venous lactate, plasma glucose, or plasma protein during the prolonged exercise. A significant decrease in respiratory exchange ratio was noted. Significant changes also occurred in hematocrit, Hb, Na+, K+, and osmolality. An interesting finding was the pre-exercise expansion of the plasma volume.

Adipose Tissue↗
PubMed1981

Oxygen deficit during incremental exercise.

The oxygen deficit and debt have conventionally been determined during exercise at constant work rates. During this study these were calculated during and after exercise at progressively incremented work rates. Five men performed two successive incremental exercise tests to exhaustion on an electronically braked cycle ergometer. The two tests were separated by a 5 min rest period. The oxygen deficit was defined as the sum of the minute differences between the measured oxygen uptake and the oxygen uptake occurring during steady state work at that same rate. The oxygen deficit was quantified for the work periods before and after the anaerobic threshold (AT) as determined from respiratory gas analysis (ATR). The measured deficit for the period before the ATR was smaller than the deficit measured in the same subjects during steady state work at low intensity (below the ATR) and was also less than the rapid component of the oxygen repayment as determined after the second incremental test. It was concluded that this test could be used for the determination of anaerobic capacity as represented by the total oxygen deficit (within motivational limits), but that the lactacid and alactacid components of the deficit could not be differentiated. A considerable portion of the alactacid component of the deficit was incurred after the onset of the ATR.

Adolescent↗
PubMed1981

The effects of prolonged exercise on spinally injured subjects.

The effects of prolonged exercise on paraplegics have not been reported. Seven male paraplegic subjects with spinal lesions from T4 - T12 - L1 underwent an incremental wheelchair treadmill test to exhaustion. Heart rate (HR), VO2max, and VESTPD were recorded and calculated. One week later, subjects exercised in their wheelchairs at approximately 50% (mean = 52 +/- 2%) of VO2max for 60 min on a motorized treadmill. Approximately 10 ml venous blood was withdrawn both 10 min and immediately prior to the prolonged exercise, at 20, 40, and 60 min of the exercise period, and at 10 min post-exercise. Venous blood was analyzed for glucose, hemoglobin, lactate, Na+, K+, Cl-, and plasma protein. Hematocrit was recorded and plasma volume changes calculated VO2, VE, and HR were recorded at 17, 37, and 57 min of the prolonged exercise. The mean VO2max was 29.5 +/- 2.7 ml.kg-1.min-1, with a mean max VESTPD and HR of 61.86 +/- 4.98 1.min-1 and 174 +/- 4 b.min-1, respectively. The changes in VO2 and VE during the prolonged wheelchair exercise were not significant. Significant changes occurred in venous lactate and plasma glucose concentrations during prolonged wheelchair exercise. Plasma volume changes were similar to those seen in able-bodied subjects. A notable finding was the pre-exercise hemodilution. Present data indicate that paraplegics can exercise at approximately 50% VO2 for 60 min, producing responses similar to those in able-bodied subjects.

Adult↗