Exercise-induced hypoxemia [EIAH, arterial PO2 < 90 mmHg and/or alveolar-arterial oxygen partial pressure gradient (A-a DO2) ≥ 25 mmHg] occurs during strenuous exercise in some healthy women. There is conflicting opinion if performing successive bouts of strenuous exercise reduces the severity of EIAH. The aim was to (a) test the hypothesis that the severity of EIAH would be reduced with three successive bouts of strenuous exercise, (b) to determine if repeated bouts of exercise increases hyperventilation thus improving arterial PO2. Seven fit female subjects with EIAH [arterial PO2 or PaO2= 88 +/- 2 mmHg, A-a DO 2 = 25 +/- 3 mmHg and 7 fit female control subjects (PaO2 = 100 +/- 5 mmHg, A-a DO2 = 16 +/- 5 mmHg) performed three bouts of intense exercise on a cycle ergometer at 236 +/- 27 watts [oxygen consumption at end of each set = 48 +/- 6 mL/kg/min, or 96 +/- 5% of maximum] for 5 min each with 10 min of rest between sets. Arterial PO 2 increased [EIAH Delta = +4 +/- 5 mmHg. 95% CI = 0.6 to 7.8; Control Delta = +2 +/- 2 mmHg. 95% CI = 0.4 to 3.6] and arterial PCO 2 or PaCO2 decreased [EIAH Delta = -5 +/- 4 mm Hg, 95% CI = -7.4 to -2.2; Control Delta = -4 +/- 2 mmHg, 95% CI = -5.8 to -2.4] between set 1 and set 3 (P< 0.05). Also, 34% of the variance in the change in PaO2, was explained by the variance in the change of PaCO2 (P < 0.05). In conclusion, repeat exercise improves PaO2, which is related to improved hyperventilation.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.98792 |
| Date | January 2006 |
| Creators | Saul, Lloyd. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Kinesiology and Physical Education.) |
| Rights | © Lloyd Saul, 2006 |
| Relation | alephsysno: 002479590, proquestno: AAIMR24793, Theses scanned by UMI/ProQuest. |
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