The purpose of this investigation was to assess the effects of instructions—to think particular types of thoughts—on the cross-country skiing performances of elite skiers. Eighteen members of the Canadian Cross-Country Ski Team served as subjects. Instructions were given to plan and think particular types of thoughts while skiing, namely task-relevant statements, mood words, and positive self-statements. Performances on a standard test track under thought control conditions were compared to similar efforts under “normal” (control) thinking. Thirteen subjects also recorded heart rates at the completion of each trial. A balanced order design of two replications of each condition was employed in each of the three experiments. Sixteen subjects improved in all conditions whereas two subjects improved in only one condition. Heart rates were marginally higher and statistically significant in each experimental condition compared to the control condition. Performance improvements of more than 3% were registered under each thought content condition, even though all subjects reported that they were not aware of any effort differential. That performance improvements of this magnitude could be achieved in athletes of such a caliber indicates the value of attempts to use the particular forms of thoughts employed in this study for improving cross-country skiing performance.