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Prediction of triathon performance from ventilatory threshold measurements Langill, Robert H.


The purpose of this study was to predict Ironman Triathlon (2.4 mile swim, 112 mile cycle, 26.2 mile run) performance times from ventilatory threshold (TVENT) measurements of swimming, cycling, and running. Ten trained triathletes (mean age = 29.7yrs., ht = 179.8cm, wt = 76.8kg, bodyfat = 11.4%) performed progressive intensity tests for treadmill running, cycle ergometry, and tethered swimming. The excess CO2 elimination curve was used to determine TVENT in each component sport with the resulting estimated times of 64.2, 380.0,174.5, 672.8 minutes for swimming, cycling, running, and overall time respectively. Individual estimates were then compared to actual segment and overall times to produce the following linear regression equations for predicting actual from estimated time (in minutes): actual swim = 1.15 * estimated swim - 6.75 actual cycle = 0.22 * estimated cycle + 262.6 actual run = 3.03 * estimated run - 267.1 actual overall = (-3.58 * est. swim) + (-0.10 * est. cycle) + (3.76 * est. run)+ 291.35 Significant correlations of r = 0.83, 0.70, 0.76, and 0.89 were calculated between swim, cycle, run, and overall estimated versus actual times respectively. Thus, between 49 and 69% of the variance in actual time is explained by TVENT for that component sport. Also, 78% of the total variability was accounted for by the TvENT estimation when the three sports were combined. These findings suggest that while TvENT is able to account for a significant proportion of triathlon performance time other factors such as fatigue, dehydration, terrain, heat, etc.are confounding the overall prediction.

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