One of the most enjoyable tools that swimmers have at their disposal to improve performance is overspeed training.
Highly fun.
The concept is straightforward:
Swim or walk out against resistance tubing that is belted around your waist until it’s really really taut, hold onto the wall for a few breaths, and then let the tension pull you back to the wall at Mach 5.
The wave that thunderclaps into the wall is always awesome. And on the surface, the reasoning for why we do this kind of training makes sense:
Overspeed swimming shows you what truly elite speed feels like.
It’s an appealing idea, but the problem is that the body doesn’t just learn speed, it’s also learning movement patterns.
How Overspeed Training Impacts Swim Speed
The goal with overspeed swimming is to teach the nervous system what elite speed feels like. With enough repetitions, the body soaks up the coordination, limb velocity, and body position of higher swimming speeds and applies it to our regular swimming.
It’s also incredibly fun. I mean, come on—who doesn’t love swimming twice the speed they usually can!
But does it actually improve sprint swimming performance?
And the answer is… sort of. Maybe. And not as much as we would like.
In one study (Girold et al., 2007), researchers had swimmers do three weeks of assisted sprint training, resisted sprint training, or regular swim training. All three groups did their usual swim workouts, with the assisted and resisted groups bolting on three additional specialized sets per week.
The resisted group improved the most. Upper-body strength went up, 100m freestyle times improved by ~2%, and swimmers increased stroke rate while maintaining stroke length. All good stuff.
The overspeed group got faster too, but improvements were much smaller. And more importantly, stroke length went down while stroke rate increased. Swimmers had to turn over the arms faster to make up for reduced distance per stroke to see those gains.
Overspeed Swimming Changes the Stroke
To understand why overspeed swimming can lead to soft performance outcomes, it’s helpful to see what it does to our stroke.
A study (Williams et al., 2006) had junior elite swimmers sprint freestyle under three conditions: assisted, resisted, and normally. During overspeed swimming, they moved about 16% faster than normal.
As expected:
- Stroke rate increased
- Stroke length increased (they were getting towed, after all)
- Average swimming velocity jumped
But the way they moved through the water is where things get a little spicy.
Even though they were moving faster through the water, hand speed didn’t increase. They were not pulling harder or faster to match the increased swimming speeds.
Think of it this way: overspeed swimming is like riding your bike downhill. Speed shoots up, but you aren’t producing more power when pedaling.
And more notably, stroke technique changed during the overspeed condition. Swimmers used a shallower hand path to keep up with the rapid flow of the water around them.
Which brings us to the main problem with overspeed training: it forces swimmers to reorganize their stroke to cope with faster flowing water.
The nervous system isn’t learning what it takes to swim at supra-max speeds, but it’s instead learning a new stroke pattern.
Resisted vs Assisted Swimming
Now, I know what you might be thinking—doesn’t resisted swimming change your stroke technique, too?
And you would be absolutely right.
When swimmers add load to the stroke, it changes in several important ways.
Stroke coordination narrows—there is less catch-up in the stroke as swimmers have to generate more consistent propulsion. The hand entry becomes more aggressive, too, replacing a long, relaxed glide with a sharper, more immediate catch.
Research also shows that technique-focused resisted swimming—not the all-out power work most swimmers associate with resistance training—can improve body position by reducing excess roll and lateral movement (Skorulski et al., 2025).
In a sense, with assisted swimming you are borrowing speed, while with resisted swimming, you have to work for it. But in both cases, the body self-organizes to move through the water more efficiently.
How to Use Overspeed Swimming Properly
So far we have thrown a wet towel on assisted/overspeed swimming, but don’t let that dissuade you from using it. Just means that you should be aware of its limitations.
Overspeed swimming can still be a useful tool for swimmers looking for a jolt to their stroke rate and nervous system. Particularly helpful for the strength-heavy swimmer who can generate lots of force with each stroke but struggles to turn up the RPM.
Here’s how such a sprint set would look like:
3-5 rounds:
- 25m overspeed swimming
- 20s rest
- 25m fast
- 50 easy
The key part is the unassisted sprint. That’s where you teach your body to reproduce the faster stroke rate under its own power.
A study (Lee et al., 2025) showed that two 20m assisted sprints led to faster 50m breaststroke times compared to a regular warm-up. Stroke rate also jumped, suggesting that overspeed work as a “primer” can wakey-wakey the nervous system before fast swimming.
To get the most from it, use overspeed training with either resisted swimming (which helps preserve force production) or regular sprint swimming to transfer that higher tempo into race-specific mechanics.
And look, overspeed swimming is just a lot of fun, and there’s value in seeing what it feels like to move across the pool at speeds that make the lane ropes rollick and sway.
Wrapping Things Up
Use overspeed swimming to expose yourself to higher stroke rates. Prime the nervous system before sprinting. Or just to shake up a dry training session and remind yourself what it feels like to split the pool in half.
Just remember that it’s not a replacement for developing real speed and power. On race day, speed comes from being able to generate more force and displace more water while holding your stroke together.
Borrow that speed once in a while, just remember to earn it the rest of the time at practice.
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 here.
