Figure 1. Experimental protocol timeline.

Dose responses for the α₁-adrenoreceptor agonist phenylephrine (0.025, 0.05, 0.1, 0.15, 0.2, 0.4, 0.8 μg kg⁻¹ min⁻¹) and the α₂-adrenoreceptor agonist BHT-933 (1, 2, 2.5, 5, 7.5 10 μg kg⁻¹ min⁻¹) were determined during normothermia and leg heating conditions. The drug order (i.e. phenylephrine or BHT-933) was randomized and equally weighted between subjects. Drugs were delivered in similar order within subjects between thermal conditions.