Effects of Three Types of Thought Content Instructions on Skiing Performance

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.

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Mechanical Energetics of World Class Cross-Country Skiing

International Journal of Sport Biomechanics ◽

10.1123/ijsb.3.4.353 ◽

1987 ◽

Vol 3 (4) ◽

pp. 353-369 ◽

Cited By ~ 31

Author(s):

Robert W. Norman ◽

Paavo V. Komi

Keyword(s):

Mechanical Power ◽

Large Individual ◽

Body Segment ◽

Energy Transfers ◽

World Class ◽

Cross Country Skiing ◽

Cross Country ◽

Power Outputs ◽

Low Energy Transfers ◽

Elite Skiers

The purpose of this study was to determine whether world class skiers were alike in their mechanical power outputs (normalized for body mass and velocity and called mechanical cost, MTC) and body segment energy transfers when skiing in competition on level and uphill terrain using the diagonal technique. Eleven competitors were analyzed from film taken during a 15-km World Championship race on a level (1.6°) and uphill (9.0°) section of the course. Metabolic rates were estimated from assumptions concerning the efficiencies of positive and negative work and calculations, from the film, of the mechanical power produced by the skiers. The results showed that skiing on the slope was 2.2 times more demanding mechanically than skiing on a level track (MTC of 4.0 vs. 1.8 J • kg−1• m−1, respectively). Skiers who had high MTC had low energy transfers (r = −0.9). Even in this presumably homogeneous group of elite skiers there were large individual differences in MTC and other mechanical variables, suggesting technique problems for some. Furthermore, on flat terrain the estimated metabolic rate was only about 76% of an MV02of 80 ml • kg−1• min−1. This suggests that speed, using the diagonal stride, may be limited by constraints on body segment utilization and not by the physiological energy delivery system of these highly trained athletes.

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