Lauren Greaves

1 INTRODUCTION Wildfire smoke (WFS) is an emerging threat to global health. Particulate matter (PM) is a principal component of WFS, and PM smaller than 2.5 micrometers in diameter (PM2.5) is of particular interest for its ability to reach the bloodstream (Naserinejad et al., 2023). Epidemiological evidence has linked WFS to increased pulmonary mortality/morbidity, but it has also been documented to increase cardiovascular events and mortality (Gao et al., 2023).

1 INTRODUCTION Traditionally, whole-body measures of metabolism have been achieved through direct or indirect calorimetry assessment of resting metabolic rate (RMR) (Divakaruni & Jastroch, 2022). While these are often considered the gold standard, and of great utility, they are whole-body estimates or a conglomerate signal and thus lack specificity to individual muscle or muscle groups, a key contributor to metabolism and glucose homeostasis (Merz & Thurmond, 2020).