Chest
Work Capacity and Cardiopulmonary Adaptation of the Obese Subject during Exercise Testing
Section snippets
Subjects
We studied 12 obese patients and 12 normal subjects matched for age and sex, all employed as administrative or teaching staff, both groups being untrained and without cardiorespiratory disorders.
In the obese group there were six male and six female subjects whose mean age (±SE) was 25.9 ± 2.3 years (range, 17 to 42 years). The control group consisted of six male and six female subjects whose mean age was 27.7 ± 1.8 years (range, 19 to 39 years).
The body mass index (BMI, kg/m2) was taken as a
RESULTS
As shown in Table 1, the ERV and the FRC were significantly decreased in the obese patients. There was no significant difference in all the other lung function variables measured. The oxyhemoglobinic saturation was within normal limits in the obese and normal subjects both during rest and muscular exercise.
The peak work rate achieved did not differ significantly from normal to obese subjects (136 ± 11.6 W in controls, 120 ±9 W in the obese patients). The anaerobic threshold, expressed as work
DISCUSSION
Our results do not show a significant difference in the maximal sustainable work capacity between normal subjects and markedly obese patients (BMI: 39.9 ±1.1 kg/m2). The anaerobic threshold, however, was reached at a significantly lower work rate in the obese patients (p<0.05). According to Wasserman,21 this implies that the endurance time at maximal effort is less in obese patients than in normal subjects as a result of the increase in arterial lactate with subse-quent metabolic acidosis.
ACKNOWLEDGMENTS
The authors would like to thank Prof. J. Milic-Emili and Prof. D. Olivieri for their critical review of the manuscript.
REFERENCES (33)
- et al.
Detecting the threshold of anaerobic metabolism in cardiac patients during exercise
Am J Cardiol
(1964) - et al.
Effect of altering heart rate on oxygen uptake at exercise onset
Chest
(1989) - et al.
Effect of obesity on respiratory function
Am Rev Respir Dis
(1983) - et al.
Compliance of the respiratory system and its components in health and obesity
J Appl Physiol
(1960) The oxygen consumption and efficiency of the respiratory muscles in health and emphysema
J Clin Invest
(1959)- et al.
The ventilatory stress of exercise in obesity
Am Rev Respir Dis
(1984) - et al.
The threshold of anaerobic metabolism in chronic obstructive pulmonary disease: a promising index of evaluation
Am Rev Respir Dis
(1971) - et al.
Determination of anaerobic threshold for assessment of functional state in patients with chronic heart failure
Circulation
(1983) - et al.
Exercise testing in the evaluation of the patient with chronic cardiac failure
Am Rev Respir Dis
(1984) - et al.
Anaerobic threshold alterations caused by endurance training in middle-aged men
J Appl Physiol
(1979)
The significance of the aerobic-anaerobic threshold transition for the determination of work load intensities during endurance training
Eur J Appl Physiol Occup Physiol
Relationship of the anaerobic threshold with the 5 Km, 10 Km and 10 mile races
Eur J Appl Physiol Occup Physiol
Determination of anaerobic threshold by ventilation equivalent in normal individuals
Respiration
The time course during 36 weeks' endurance training of changes in max and anaerobic threshold as determined with a new computerized method
Cli Sci Lond
Anaerobic threshold of middle and old aged men
The simple measurement of obesity
Cli Sci
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