For all of my swimming career I heard advice like “go out fast and hold on” and so it’s nice to see real numbers and results to back up recommended pacing strategies
The goal of this study was to answer the following questions:
In international swimming competitions (think 50m pool), how does the pacing of each lap affect the final race time.
How do finalists pace their races and is that different from the way non-finalists pace?
How much change is needed (and the nature of that change) for a swimmer to place better or possibly earn a medal
The researchers found that in races lasting less than 60 seconds (100s and 50s )the best strategy is to start the race at 100%, but in 200s & 400s the best strategy is to start fast and fallback to an even pacing strategy. If I am reading this right then "the start" is referencing the entire first part of the race and not just the dive. Does this really mean that the swimmer who goes a 51 in the 100 free should go out sprinting for the first 20 or so meters?
A few interesting patterns emerged: (1) Of the 16 swimmers that advanced they all had a similar pacing pattern, (2) in the 100m free the winners had a faster final lap than the others and (3) the winners of the 200 & 400 free held the lead throughout the duration of the race.
In the 100, the lap that had the most bearing on the final time was the last lap/half of the race and in the 200 & 400 the determining lap was the 2nd and 3rd 50. With that knowledge it makes sense for coaches to focus on improving those laps for greater improvement.
In most events male and female lap time patterns were quite similar except in the 100m free. The winners of the men's 100 free had a slower first lap than the silver medalist, but less of a time drop off and in the women's 100m free the winners were faster than their competitors in both laps.
By evaluating all of these performances it seems that less successful swimmers need to prioritize fitness and technique over pacing strategy.
So what does it take to improve? Well if you're talking about improving from heats to finals then there needs to be a time improvement of ~1% and another 0.4% to reach the medal podium. To achieve that improvement it is recommended that swimmers target the laps that have the strongest relationship with the final time and do so without disrupting the overall pattern of racing.
So it would seem that the ideal racing/pacing strategy for an elite 100m freestyler is to sprint the first portion of the race and maintain the speed in the final lap while mid distance swimmers should aim to maintain the lead for whole race.