Research regarding the effect of cold exposure on metabolism and substrate utilisation during exercise has produced inconsistent results. Intensity of exercise and training status of subjects are known to impact metabolism and substrate utilisation regardless of environmental conditions. Duration and intensity of cold exposure during exercise also may exert impact. Thus, systematic manipulation of these variables (fitness, intensity of exercise, cold conditions) should provide a means to determine metabolic and substrate utilisation patterns when exercising in the cold. However, a number of variables have been introduced into research methodologies that may confound results. Duration and intensity of cold exposure prior to exercise, and acclimation and clothing status of subjects may confound or override the influence of other variables. Future research addressing the impact of cold exposure on metabolism and substrate utilisation during exercise must attempt to isolate and control each influential factor (prior to and during exercise), and must be alert to the interactive effects that can occur.