Performance Variability in the Throwing Events

Background: Large forces are exerted by Olympic throwers on their implements. It was hypothesized that at the limits of an individual's capability for force production, there would be a large variation in accuracy in task performance.

Methods: Data from the throwing events (shot put, discus throw, javelin throw and hammer throw) at the XXX Olympic Games (London, 27 July – 12 August 2012) were analysed for both qualifying and final rounds to investigate variability in participant scores. The dispersion was expressed in the form of a coefficient of variation (CV). Computationally extensive methods, namely bias-corrected and accelerated (BCa) bootstrapping using a Mersenne Twister were utilised in confidence interval {CI) estimation for CV. Bootstrapping, utilised at 10000 samples per CV, allowed conservative assumptions about data distribution, whilst BCa allowed correction for bias and skewness (at expense of computational resources).

Results: The within subjects coefficient of variation (CV) for all throwing rounds was 0.0240 (95%CI 0.0211- 0.0277). Comparison to track data further supported the higher degree of variability in throwing events claimed in previous literature on the IAAF Grand Prix. The mean within subjects coefficient of variation (CV) for javelin was 0.0312 (95%CI 0.0266-0.0364), the highest for the four throwing events and this variation was also significantly larger than either shot put 0.0155 (95%CI 0.0122- 0.0190) or discus 0.0205 (0.0172-0.0241). The throwing distances in the final rounds had higher CV than qualification stages, though this was not significant. For the men's hammer in particular the final round within subjects CV (0.0449, 95%CI 0.0100-0.1094) was more than double the qualification round CV (0.0199, 95%CI 0.0142-0.0276), however there was significant 95%CI overlap.

Discussion &Conclusion: CV values evidenced a large degree of variability in the throwing events at the XXX Olympic Games, a finding in line with previous literature on athletics.