Little is known about the reliability of competitive performance of athletes, even though this reliability impacts the effectiveness of performance-enhancing strategies and the ability of researchers to delimit worthwhile performance enhancements. We have therefore analyzed the reliability of competitive performance of elite male Olympic triathletes. We searched the Web for official results of international Olympic triathlons that included times of the swimming, cycling, and running stages. We analyzed times for the 103 athletes who entered two or more of nine such events, held between April 1997 and November 1998. Means and standard deviations for swim, cycle, run, and total times were 19.5±0.5, 59.8±1.5, 35.1±1.6, and 115.0±2.9 min respectively. Our measure of reliability was the typical within-athlete variation, derived as a coefficient of variation by analysis of variance of log-transformed times. Findings: (a) Within-athlete variations (and 95% likely ranges) were: swim 1.6% (1.4 to 1.7%), cycle 2.3% (2.1 to 2.5%), and run 3.6% (3.3 to 3.9%). When combined independently or dependently, these variations yielded predicted variations in total time of 1.6% or 2.6% respectively, whereas the observed variation was 1.9% (1.7 to 2.0%). (b) Transition times, available for three events, averaged 89 s for the swim-cycle and cycle-run transitions combined. Within- and between-athlete variations for the transitions were less than 10 s. (c) Time between pairs of events (14-567 days) had no noticeable effect on reliability. (d) Analysis of the mean within-athlete variation for each event paired with every other event showed that total time was less reliable in two events (means of 2.1% vs. 1.5-2.0%) owing to lower reliability of running (means of 4.3% vs. 3.2-3.7%). The duration of the runs was 3.5-13% longer in these two events, which were held under very hot conditions. (e) The top-half athletes, who averaged 3.7% faster than the bottom-half, had smaller variations for total time (1.4% vs 2.2%) and for each of the three phases. Conclusions: (a) Factors that affect performance of individual elite triathletes act largely independently in the three phases. (b) No worthwhile gains in performance are possible in the transitions. (c) Elite triathlon performance is remarkably stable over an 18-month period. (d) The outcome of a triathlon staged in a hot environment is less predictable than normal. (e) Recent work has shown that the smallest worthwhile performance enhancement is about half the within-athlete variation, so coaches and sport scientists should focus on enhancements of as little as 0.7% in total time for top triathletes.
© Copyright 1999 5th IOC World Congress on Sport Sciences with the Annual Conference of Science and Medicine in Sport 1999. Alle Rechte vorbehalten.