Arctic ground squirrels (AGS) undergo extreme temperature fluctuations during the hibernation season (body temperature, Tb, as low as −3 °C), where they mostly remain physically inactive. During interbout arousals, once Tb reaches ~16°C, hibernators recruit skeletal muscle (SkM) for shivering thermogenesis to attain Tb of ~37°C. Dietary polyunsaturated fatty acids (PUFA) are known to affect both SkM function and metabolism. Recent studies in cardiac muscle of hibernators have shown an increased level of ω‐6 in ω‐6:ω‐3 PUFA ratio are correlated to sarco/endoplasmic reticulum Ca‐ATPase (SERCA) activity with respect to torpor and hibernation status. SERCA catalyzes the re‐uptake of Ca2+ back into the sarcoplasmic reticulum (SR), which was previously bound to actin/myosin filaments thus completing the calcium cycle and eliciting muscle relaxation. We hypothesized that diet (increased ω‐6:ω‐3 PUFA ratios) and torpor status play essential roles in the regulation of the SERCA pump, which may improve SkM performance during hibernation. An Ex‐vivo functional assay was used to characterize performance alterations in SkM (diaphragm) collected from AGS fed the following diets (ω‐6:ω‐3, 5:1 control diet versus ω‐6:ω‐3, 1:1 test diet) and collected at 3 timepoints of torpor (early torpor, late torpor, and arousal). Additionally, the muscles were assessed for their response to hypothermic temperature stress (4 °C; 15 °C; 25 °C and 37 °C) to determine functional resilience. To our knowledge this is the first study correlating torpor status, diet, and effects of hypothermic temperature stress on SkM functional performance in hibernators (AGS). Data suggest: 1) diet and torpor significantly alter relaxation kinetics (calcium re‐absorption), but not force development (rate of calcium release), and 2) diet, torpor status, and inherent temperature resilience (4°C; 15°C) affect the muscles ability to produce force. This evidence supports the interpretation that functional properties of SkM can be altered by membrane lipid composition, ambient temperature, and hibernation status to control performance.Support or Funding InformationThis work was supported by the INBRE IDeA Faculty Pilot Grant (University of Alaska Fairbanks ) from NIH NIGMS grant number P20GM103395.