Can a Simple Trapezoidal Integration Approach Accurately Estimate the Supra-Critical Speed Distance Capacity of a...

The 12 × 25-m swim test has become a key physiological monitoring and profiling tool within swimming networks to capture various performance insights (peak velocity, critical speed [CS], supra-CS distance capacity [D'], and anaerobic speed reserve) within one testing occasion. The D' output following the 12 × 25-m swim test is currently derived using software that requires specialised expertise, therefore inhibiting the accessibility of the test to pathways' level coaches and athletes.

The aim of the study was to determine if trapezoidal integration (TI) could simply and accurately replace the model fit method to estimate D' following the 12 × 25-m swim test and improve the accessibility of the test for a wider cohort of practitioners.

Thirty-one national-level swimmers preparing for the Paris 2024 Olympic Trials consented for their 12 × 25-m data set to be retrieved. D' was calculated using both the model fit and TI approaches. Linear regression and pearson correlations examined the strength of the relationship and a paired t test and Bland-Altman plot determined the agreement between the 2 methodologies.

A very strong, positive relationship was found between the model fit and TI D' calculations (r = .999, R2 = .999, P < .001), with a very small, nonsignificant difference of 0.040 m (d = 0.124, P = .495).

TI is a valid replacement for the original model fit approach to estimate D' following the 12 × 25-m swim test. The swim test will no longer require specialised software and the accessibility of the test will increase to a wider cohort of swimming practitioners.