ZWIM reviews

ZWIM reviews.
In their words, not ours.

“I think this will be one of the biggest products to impact swimming in triathlon since triathlon started.”

Will UsherProfessional triathlon coach (TriDot) and Founding Director of Precision CoachingTested a ZWIM unitWatch him say it, TriDot Podcast at 54:37

GTN filmed it at Kona. Triathlete put it in its hottest new gear. 220 Triathlon’s editor got humbled by it. Triathletes queued to try it in Cascais, and coaches argued about it on Slowtwitch. Here’s all of it, including the people who aren’t sold.

Pre-order ZWIM Watch the videos
  • Kona 2026: in GTN’s Ironman World Championship tech round-up
  • “The hottest (and coolest) new gear” at Kona 2026
  • The editor’s first session: “humbling”
  • 30 daysrisk-free at home once yours arrives

ZWIM ships from 28 December. Until owners have trained on it at home, there's no star rating for ZWIM on this page. When they have, their reviews go here, good and bad.

Last updated · Kept up to date by Victor Jarland, ZWIM founder

ZWIM reviews: the short version

  • Coach Will Usher (TriDot) called ZWIM “one of the biggest products to impact swimming in triathlon since triathlon started.”
  • What coaches single out is the live feedback: Propulsive Watts, your power and efficiency in one number, on every stroke.
  • GTN featured ZWIM in its Kona 2026 tech round-up, Triathlete listed it in its hottest new gear, and 220 Triathlon’s editor called her first session humbling.
  • The main criticism is that it supplements swimming rather than replacing it. We agree: the pool stays.
  • Owner reviews come after the Founding Batch ships from 28 December. Until then, this page shows coaches, pros, the press and triathletes who tried it.
  • You get 30 days to train on it at home. If it’s not for you, send it back for a full refund.
On camera

What triathletes say after trying ZWIM

Triathletes who tried ZWIM at the IRONMAN Cascais expo. Tap one to play it with sound.

Why I changed my mindIRONMAN Cascais expo
Why I'm upgrading from ZEN8 Swim TrainerIRONMAN Cascais expo
Ten-minute sessionsIRONMAN Cascais expo
The stroke feedbackIRONMAN Cascais expo
What surprised meIRONMAN Cascais expo
I learned to swim from YouTubeIRONMAN Cascais expo
Training at homeIRONMAN Cascais expo
Why we built itVictor Jarland, ZWIM founder
On YouTube

ZWIM on YouTube: GTN, The Daily Tri and TriDot

Kona, 8 Oct 2026

The hottest triathlon tech from the Ironman World Championships

The Global Triathlon Network's tech round-up from the Big Island. The ZWIM segment, Virtual Swim Sessions on ZWIM, starts at 13:24.

YouTube

The Daily Tri tries ZWIM indoor swim training

Coach Will Usher

A pro coach on testing ZWIM

“I think this will be one of the biggest products to impact swimming in triathlon since triathlon started.” Will Usher, professional triathlon coach at TriDot, on ZWIM's live efficiency score.

Short

Would you try a Zwim session?

In print

What the press says about ZWIM

The Hottest (and Coolest) New Gear at the 2026 Ironman World Championship

Zwim is the “gamified” but also quantified version of the beloved dryland tool.
Chris Foster, Editor-in-Chief, Triathlete · Oct 2026
Read the article
Sponsored feature

Struggling with the swim? How a first-race panic attack led to a new way to train at home

A short training session with the team ahead of launch was humbling for me (an open-water swim coach and seasoned distance swimmer), to say the least. Scores were low. Muscles in my back and shoulders I'd never noticed before started making themselves known.
Helen Webster, Editor, 220 Triathlon · 15 Oct 2026
Read the article

Beyond 'surviving the swim': The couple behind ZWIM's smart training revolution

Designed to accompany and work alongside regular pool work, ZWIM Smart Trainer is for those days in between.
Matthew Reeder, TRI247 · 9 Oct 2026
Read the article
Coaches, pros and science

What coaches, pros and scientists say about ZWIM

“I use ZWIM because it’s a really good way – and pretty much the only way – of tracking how you’re producing power through the stroke, and then also taking that power and putting it into an efficiency score, which tells me how efficient I’m being with that.”
Kieran Lindars Pro triathlete. British IRONMAN record holder, 7:32:03 (IRONMAN Texas 2026). 8th at the 2024 IRONMAN World ChampionshipZWIM Performance Coach and shareholderRead it in 220 Triathlon
“Sometimes the most effective intervention is not to swim more, but to understand precisely what is limiting my stroke. ZWIM is designed to provide information about how the swimmer produces force during the swimming action, helping identify where greater contribution or improvement may be needed.”
Professor Mário J. Costa University of Trás-os-Montes and Alto Douro (UTAD). Specialist in aquatic sports scienceWorked with ZWIM on product developmentRead it in 220 Triathlon
“The real-time feedback is the standout feature. Rather than simply completing repetitions, you’re receiving information that encourages you to adjust what you’re doing as you do it.”
Will Usher Professional triathlon coach (TriDot) and Founding Director of Precision CoachingTested a ZWIM unit · Sponsored 220 featureRead it in 220 Triathlon
“You can’t be lazy on it because it’ll be constantly reminding you when your technique’s falling apart. And with swimming, there’s an argument that once your technique is dropping off, there’s no point just ploughing through because you’re then just training bad technique.”
Kieran Lindars Pro triathlete. British IRONMAN record holder, 7:32:03 (IRONMAN Texas 2026). 8th at the 2024 IRONMAN World ChampionshipZWIM Performance Coach and shareholderRead it in 220 Triathlon
The honest take

The honest criticism of ZWIM

“I have tried Zwim myself, and while I think it is an interesting training tool, I would not necessarily recommend investing in it unless you really struggle to find time to get to the pool... I would consider it a supplement rather than a replacement for swimming.”
A triathlon coach on the Slowtwitch forum, Oct 2026 · Read the thread
Our answer

It is a supplement, and we'd never sell it as anything else. ZWIM trains the catch, pull and push. Body position, rotation, breathing and feel for the water stay in the pool, and always will. If two swims a week is what life allows, ZWIM fills the days in between. If you already swim six times a week, it gives you a benchmark for your power and efficiency, and puts more load through your stroke than the water can.

Questions

ZWIM questions, answered

Is ZWIM worth it?

Yes, whether you swim twice a week or six times. ZWIM gives you 10 to 35 minute sessions at home with Propulsive Watts, your power and efficiency in one live number, on every stroke. It's a benchmark you can track over time, and it puts more load through your stroke than the water can. Coaches who've tried it call it a supplement to swimming, not a replacement. We agree.

What do coaches and pros say about ZWIM?

Will Usher, a professional triathlon coach at TriDot and Founding Director of Precision Coaching, said on the TriDot Podcast: “I think this will be one of the biggest products to impact swimming in triathlon since triathlon started.” He told 220 Triathlon: “The real-time feedback is the standout feature.”

Kieran Lindars, the British IRONMAN record holder and ZWIM’s Performance Coach, says ZWIM is “a really good way – and pretty much the only way – of tracking how you’re producing power through the stroke.”

Triathlete’s editor-in-chief Chris Foster called it “the ‘gamified’ but also quantified version of the beloved dryland tool.”

Is ZWIM worth it if I already swim a lot?

Yes. Even if you swim six times a week, ZWIM gives you a benchmark for your power and efficiency that you can track over time, and it puts more load through your stroke than the water can.

What does ZWIM measure?

The ZWIM Smart Paddles read every stroke, each arm separately: how hard you press, in which direction and how efficiently. That becomes Propulsive Watts, your power and efficiency in one live number. Kick, rotation and breathing stay pool work.

Does ZWIM replace swimming?

No. ZWIM trains the propulsion phase of your stroke: the catch, pull and push. Body position, kick, rotation, breathing and sighting are work for the pool and open water.

Are there ZWIM owner reviews yet?

Not yet. The Founding Batch ships from 28 December. Owner reviews go on this page once people have trained on it at home.

What you hear and see today is people who have trained with ZWIM for months, or tried ZWIM at our expo, including owners of our first swim trainer.

What if I don't like ZWIM?

You can train with ZWIM risk-free for 30 days at home. If it's not for you, send it back for a full refund of the ZWIM Smart Trainer and your membership. Change your mind before it ships and you can cancel for a full refund.

Now try it on your own stroke

You've heard what the coaches, pros and press think. See your own Propulsive Watts. Train with ZWIM risk-free for 30 days at home, and if it's not for you, send it back for a full refund.

Pre-order ZWIM