Physiologic, Psychological, Nutritional, and Rest-Activity Observations During 120 Days of Low-Tech Off-Grid Living...

Off-grid low-tech living is increasingly proposed for arid environments, yet longitudinal field data documenting health, nutrition, and rest-activity organization under real-world conditions remain scarce. Our objective was to describe physiologic, nutritional, psychological, and rest-activity trajectories during 120 d of low-tech off-grid desert living. This was a prospective observational case study of 2 participants (female, 29 y old; male, 39 y old) conducted in Baja California (January-April 2023). Pre-, mid-, and post-mission assessments included bioimpedance body composition, incremental cycle ergometry with gas exchange (VO_{2 max} and ventilatory thresholds), and laboratory panels (eg, hematology, iron status, vitamins, trace elements, and renal and hepatic indices). Mental health was assessed using the State-Trait Anxiety Inventory, the Positive and Negative Affect Schedule, and daily mood ratings. Continuous wrist actigraphy quantified sleep-wake timing and nonparametric rest-activity metrics. Analyses were descriptive and within participant. Body mass decreased by ∼2 kg in both participants, primarily through reduced fat mass with preserved lean indices. VO_{2 max} increased over time without evidence of physiologic compromise. No biochemical marker of micronutrient deficiency was identified. Although locally produced foods contributed ∼1% of total energy intake, they provided substantial micronutrient density. Ferritin levels remained within reference intervals despite transient mid-mission fluctuation in the female participant. Rest-activity rhythms remained robust across 120 d, with seasonal adjustment of sleep timing and modest sleep reduction. Anxiety did not increase, and affect balance remained positive. In this descriptive field case, prolonged low-tech off-grid desert living was compatible with maintenance of physical and psychological health. These findings provide ecologically grounded observations relevant to human functioning in resource-limited environments.