A national Task Force of 25 Australian physiology educators used the Delphi protocol to develop seven physiology core concepts that were agreed to nationally. The aim of the current study was to unpack the "physiological adaptation" core concept with the descriptor "organisms adjust and adapt to acute and chronic changes in the internal and external environments across the lifespan." This core concept was unpacked by three Task Force members and a facilitator into four themes and nine subthemes that encompass the role of stressors and disturbed homeostasis in adaptation and the capacity for, and the nature of, the physiological adaptation. Twenty-two Task Force members then provided feedback and rated the themes and subthemes for level of importance and difficulty for students to learn via an online survey using a five-point Likert scale. Seventeen respondents completed all survey questions. For all themes/subthemes, importance was typically rated 1 (Essential) or 2 (Important) (n = 17, means ±SD ranged from 1.1 ± 0.3 to 2.2 ± 0.9), and difficulty was typically rated 3 (Moderately Difficult) (n = 17, means ranged from 2.9 ± 0.7 to 3.4 ± 0.9). Subtle differences in the proportion of importance scores (n = 17, Fisher's exact: P = 0.004, ANOVA: F12,220 = 2.630, P = 0.003; n = 22, Fisher's exact: P = 0.002, ANOVA: F12,281 = 2.743, P < 0.001), but not difficulty scores, were observed between themes/subthemes, and free-text feedback was minor. The results suggest successful unpacking of the physiological adaptation core concept. The themes and subthemes can inform the design of learning outcomes, assessment, and teaching and learning activities that have commonality and consistency across curricula.