Exercise in the heat is associated with cardiovascular and thermoregulatory disturbances that can persist postexercise. The effect of orthostasis on autonomic nervous system function following exercise-induced hyperthermia (EIH) remains to date unclear. Insight into the mechanisms of control is beneficial to those encountering orthostatic challenges after activity-induced hyperthermia.
We evaluated the short-term postexercise cardiovascular and thermoregulatory responses to repeated orthostatic challenges performed in a hyperthermic state and the effects of EIH on autonomic nervous system function during repeated orthostatic challenges in the early and late-stages of recovery.
We conclude that following EIH, the cardiovascular system maintained arterial pressure and cardiac output during repeated 70° head-up tilts. Nonthermal baroreceptor control predominates over thermal control of cutaneous vascular conductance during postural challenges following EIH, but no effect was observed in local sweat rate. The short-term reductions in baroreceptor sensitivity and heart rate variability following EIH were re-established following a 24-h recovery period.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/28362 |
| Date | January 2009 |
| Creators | Armstrong, Rachel G |
| Publisher | University of Ottawa (Canada) |
| Source Sets | Université d’Ottawa |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 127 p. |
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