The once low prevalence of non‐insulin‐dependent (Type 2) diabetes (NIDDM) in Eskimos and Indians has risen approximately fourfold over the past 30 years, suggesting the presence of a non‐genetic factor affecting NIDDM prevalence. At the same time, traditional physical activities required of a subsistence (self‐sufficiency) lifestyle have diminished. Since physical activity has been shown to prevent NIDDM in other populations, we performed a case–control study of physical activity and glucose intolerance in 666 Yup'ik Eskimos and Athabaskan Indians ≥40 years old in 15 villages in the Yukon Kuskokwim Delta in Alaska. Self‐administered questionnaires were used to determine whether subjects participated in a number of traditional activities and/or their modern counterpart (for example, dog sledding and riding motorized vehicles). Intensity values and a score were defined for the activities. Cases included known or newly discovered impaired glucose tolerance or NIDDM. Newly discovered cases were defined by oral glucose tolerance testing of those individuals were screening blood glucose values ≥6.7 mmol l−1 by random capillary blood glucose testing.