Weight and length data collected during the summers from 1984 through 1994 were used to examine the seasonal life history strategy of Arctic ciscoesCoregonus autumnaliscollected from Prudhoe Bay, Alaska. Differences in observed and predicted weight were used to determine if condition increases during the summer feeding season when energy reserves are accumulated and decreases during winter when energy reserves are depleted. Data from proximate body analyses of lipid and protein content collected from 1991 to 1993 also were examined. Condition was indexed as residual values generated from a whole population least-squares regression of loge-transformed weight and length data. For data pooled by individual year-classes, we tested the conceptual hypothesis that mean residual value, mean lipid content, and mean protein content increased during summer and decreased during winter. For the 12 year-classes examined, concurrent mean residual values supported our conceptual hypothesis in 61 of 76 instances (P< 3.0 E-7), but for mean lipid content and mean protein content, our hypothesis was supported in only 13 of 21 cases (P= 0.14) and had to be rejected. However, 6 of the 8 failures in lipid change and 7 of 13 failures in residual change were associated with summer 1991. Data suggested that Arctic ciscoes did not accumulate lipid reserves during summer 1991 and that relative condition analysis detected this anomaly in nearly every year-class examined. Results were therefore consistent with a strategy of accumulating energy reserves in summer and depleting those reserves to survive the Arctic winter.