Does Reaction Time Really Matter for a Fast Swim Start? ...Middle East

By Olivier Poirier-Leroy on SwimSwam

Races are often won and lost at the start. So swimmers do what swimmers do and fixate on their reaction time—how long it takes from the starter’s beep to leave the block—to judge how good their start is.

But reaction time doesn’t tell the whole story.

As it turns out, it’s less important for an explosive start than most swimmers think. A 0.60 up on the scoreboard certainly looks awesome, but it doesn’t really tell us how fast the start is.

Here’s what matters for a truly kaboom swim start.

The Impact of Reaction Time on Sprint Performance

A 2017 study published in the Journal of Physical Education and Sport looked at the start performance of 50m and 100m finalists over seven World Championships (2003-2015).

Differences in reaction time were large enough to potentially flip final placings in 4.25% of 50m events.

And when we look at the start performance of the two 50m freestyle winners at the 2024 Paris Olympics—Cam McEvoy and Sarah Sjöström—they both had the fastest reaction times among the finalists.

So yes, reaction time can certainly have an impact. But reaction time (which reflects the time spent during the block phase of the overall start) is just one piece of the puzzle.

Time-to-15m – The Metric That Matters

A better metric than reaction time for measuring start performance is time-to-15m. It better reflects all of the stuff that goes into a fast start, well, fast.

A study (Thng et al., 2020) looked at the starts of 152 high-performance (elite or national-level) swimmers to see which on-block factors predicted faster 15m times.

In other words, what are swimmers doing on the block that cranks out a fast 15m split?

Four things that stood out:

Reaction time was also measured, but it was not one of the main predictors of who reached 15m fastest.

And this is just the on-block phase of the overall start—we haven’t even considered what swimmers are doing in the air, their trunk angle at take-off, entry position, glide depth, underwater velocity, and all the other things that take them to 15m.

The swimmers who reached 15m fastest produced more force, directed more of it horizontally, and converted it into take-off velocity.

Fast Reaction Time

A powerful block phase is also properly sequenced. We aren’t sacrificing an effective start just to be more fleet-footed. When the starter’s beep goes off, there is a coordinated pattern of force production that fuels maximum take-off velocity.

Thng et al. (2021) broke down the block phase into four distinct mini-phases. Here’s how this is mapped out based on a reaction time of 0.70s:

Force production follows a coordinated pattern:

This little song-and-dance sequences force production in a way that generates as much horizontal take-off velocity as possible, the thing that truly matters for a fast start.

Reaction Time vs Start Performance

Looking at the Paris Olympics again, we see how reaction time didn’t mean faster times to 15m. In both the men’s and women’s events.

Cam McEvoy had the fastest reaction time, but he was not first to the 15m:

Same story in the women’s event.

Sjostrom was off the block first but Gretchen Walsh more than made up for a slower reaction time with her underwaters:

Reaction time is one component of what happens on the block, but time-to-15m is more important when it comes to assessing whether a start is fast or not.

So, How Important is Reaction Time?

How long it takes for you to react on the blocks matters to an extent—you don’t want to spend five seconds on the block, charging up your legs, after all—but it’s not what is decisive for a fast start.

At best, it’s a rough proxy for how quickly you can generate force. It doesn’t tell us the important stuff, like how much force is generated, how quickly swimmers leave the block, or how effectively you carry that speed to 15m.

For the enterprising sprinter looking for a more explosive start, stop chasing a twitchy 0.60s reaction with no power behind it, and focus on:

Focus on those things, and a high-performance reaction time and increased power off the block will be the natural result.

Happy sprinting!

ABOUT OLIVIER POIRIER-LEROY

Olivier Poirier-Leroy is a former national level swimmer, 2x Olympic Trials qualifier, and author of several books for swimmers, including YourSwimBook, Conquer the Pool, The Dolphin Kick Manual, and most recently, The 50 Freestyle Blueprint.

The book is a beastly 220+ pages of evidence-based insights and practical tips for improving freestyle sprint speed.

It details everything from how to master stroke rate, technique, build a thundering freestyle kick, improve your start and underwaters, and much more.

The 50 Freestyle Blueprint also includes 20 sprint sets to get you started and a bonus guide on how to master the 100 freestyle to complete your sprint preparation.

Learn more about The 50 Freestyle Blueprint today.

Read the full story on SwimSwam: Does Reaction Time Really Matter for a Fast Swim Start?

Hence then, the article about does reaction time really matter for a fast swim start was published today ( Wednesday 18/02/2026 - 03:45 PM ) and is available on swimswam ( Middle East ) The editorial team at PressBee has edited and verified it, and it may have been modified, fully republished, or quoted. You can read and follow the updates of this news or article from its original source.

Read More Details
Finally We wish PressBee provided you with enough information of ( Does Reaction Time Really Matter for a Fast Swim Start? )

Also on site :

• Rangers stars J.T. Miller, Vincent Trocheck prove Bill Guerin right at Olympics: ‘Pretty f–king proud’
• Rea the Reliever, Johnathon Long’s Injury, ABS Issues, and Other Cubs Bullets
• Pope Leo XIV: Freedom Is Fulfilled by Saying Yes to God