Triumph Triaction Sports Bra Guide: The Lines, the EU Sizes, and the Silicone Wire

If you go looking for a triumph triaction sports bra from the United States, you will find a famous name and an almost empty shelf. Triaction is the sports line of Triumph, the European lingerie house, and it is a serious range: its designs are bounce control tested by the Research Group in Breast Health at the University of Portsmouth, running from wirefree running bras to a padded studio bra built around a silicone wire. But Triumph sells Triaction through its European, British, Australian and New Zealand stores, and on Amazon US the whole range comes down to a single style, the Extreme Lite, which this site already covers. This guide disentangles the sub lines, converts the EU sizes from the brand’s own chart, and takes the Magic Motion apart, so you know what you would be importing before you pay international shipping on it.

How to use this guide. Because no fresh Triaction style is listed on Amazon US, this article carries no product cards and no comparison table, and nothing in it is padded with another brand’s bras. Every specification comes from Triumph’s own stores and size chart, the brand’s launch releases, and retailer records tied to its style numbers, checked on 29 October 2026. Our Affiliate Disclosure explains how this site normally earns, and why this page has no buying links to give.

The Triaction range at a glance

Triaction is organised by job, not by fashion season. The Cardio lines chase bounce control for running and high impact training. The Studio line, home of the Magic Motion, was built for toning and lower intensity work. Around those sit comfort and airflow designs at medium support. Every line below is sold in EU band and cup sizes in the brand’s home markets, and the cup ceilings are the brand’s own, stated in its cup sequence.

One line in that table needs a flag. The Extreme Lite is the only Triaction style with an Amazon US listing, and it is already carded on this site in our guide to the best high impact white sports bras, so it stays in prose here. Everything else reaches US readers only through international stores, which is why the sizing section below matters more than any single product.

How to buy a triumph triaction sports bra from the US

There is no US Triumph storefront and no Amazon US catalogue behind this range, so a US order is an import decision. The realistic routes are Triumph’s own overseas stores, which list the current Cardio and Studio lines in EU sizes, and international marketplaces where the same style numbers appear. Whichever route you take, the returns journey crosses a border, so the first order should be a single bra in the size the chart gives you, not a haul.

Two habits protect that order. First, shop by style number, not by name: Triaction names repeat across seasons and markets, while the number, 10165861 for the Control Lite, 10201677 for the Energy Lite, identifies the exact design. Second, read the size on the listing as an EU size until proven otherwise, because a converted label keeps the EU cup letter even when the band number has been translated, as in the sibling EU range covered in our Anita Active sports bra guide.

Triaction sizing: EU bands, EU cups, and the letter trap

Bands convert cleanly. Triumph’s own size chart pairs the systems in one row: EU 65 is a US 30, EU 70 a 32, EU 75 a 34, EU 80 a 36, EU 85 a 38, EU 90 a 40, EU 95 a 42, EU 100 a 44, EU 105 a 46 and EU 110 a 48. The EU number is simply your underbust in centimetres, rounded to the nearest five, so a US 36 band is an EU 80 everywhere Triumph sells.

Cups are where orders go wrong. The brand’s chart runs its cup column in the EU sequence, AA, A, B, C, D, E, F, G, H, with no DD and no DDD anywhere in it. US cups double as they climb, EU cups do not, so the letters agree up to D and then part company. Count steps, not letters: the fifth step, printed E in the EU sequence, is the volume US brands label DD, and the sixth step, F, is the volume US brands label DDD. Worked through, a US 36DD orders an EU 80E, and a US 36DDD orders an EU 80F. A shopper who orders by the letter she knows and buys an EU 80D has quietly bought a cup two steps small. Triumph publishes the same conversion in its fitting guide, and our sports bra impact levels guide covers matching a fitted size to a support class.

The bounce control numbers, read honestly

Triumph’s headline claim is process, not magic: the range is tested by the Portsmouth research team and sorted into classes. On the brand’s running page, Extreme Bounce Control means 68% bounce control and High Bounce Control means 50 to 65%, with the Control Lite and Extreme Lite named as the extreme class picks. The launch releases add per style ratings: 78% for the Control Lite, 73% for the front closure Control Boost F, and up to 65% for the Magic Motion push up.

Read those numbers as the brand’s own laboratory ratings, useful for comparing Triaction styles against each other and nothing more. They are not our measurements, and no other brand’s percentage is measured on the same protocol, so a 68% here cannot be lined up against a rival’s support claim. What the numbers do tell you is the range’s internal order: the wired minimiser out controls the wirefree flagship, and the studio designs sit a class below both.

Magic Motion: the sports bra built around a silicone wire

The Magic Motion is the design that makes Triaction different from any US sports bra line, and it starts with a piece of lingerie engineering. Triumph’s Magic Wire replaces the metal underwire with a flexible silicone core cushioned inside the cup padding, without the hard edge that digs and pokes through fabric. The idea came from the brand’s everyday bras, where the wire won design awards, and Triaction carried it into sport as Magic Wire Air, a lighter, perforated version built to breathe.

Know first what it is not. The Magic Motion is not the Extreme Lite under a softer name. The Extreme Lite is a wirefree Cardio design that controls bounce by encapsulation and compression; the Magic Motion is a padded Studio design built around a wire, sold under its own name in the brand’s releases and retailer records. If a listing blurs the two, trust the construction in front of you: wirefree means Cardio, padded with a soft wire means Magic Motion.

The family launched for autumn and winter 2017 in two forms. The Magic Motion MWP is the padded all rounder, launched for low intensity, toning activities in the Studio collection, with perforated cups, a cross back option and adjustable straps. Its sibling, the Magic Motion MWHU, is a push up that trades a little control for lift and still carried a certified bounce control rating of up to 65% in the launch release, the top of the High class. Later versions pushed the idea harder: retailers in markets such as India sell a Magic Motion Pro, a magic wired padded design marketed for high bounce control, so the line evolved from studio origins toward training support.

Our honest verdict: the Magic Motion is the most interesting idea in the range for a US reader who trains in studios, lifts, or hates the feel of a metal wire, because nobody in the US market builds a sports bra this way. It is not the range’s running bra, whatever a marketplace headline says; for running, Triumph itself points you to the Control Lite and the Extreme Lite. And like the rest of Triaction, it reaches the US only as an import in EU sizes, so the conversion above is the price of admission.

Common Questions

Can I buy a Triaction sports bra on Amazon US?
Only one style, the Extreme Lite, has an Amazon US listing, and it is already covered with a product card in our best high impact white sports bras guide. Every other line in this guide is sold through Triumph’s international stores and marketplaces.

I wear a US 38DD. What Triaction size do I order?
An EU 85E. The chart converts the band directly, US 38 to EU 85, and the DD volume is the fifth cup step, printed E in the EU sequence. An EU 85DD does not exist in the system, and an EU 85D would be a step small.

Is the Magic Motion supportive enough for running?
Not in its original form. It launched as a Studio design for low intensity training, and its push up sibling’s certified rating tops out at 65%, High class rather than the Extreme class reserved for running. The later Pro versions claim more, but Triumph’s own running page still sends runners to the Control Lite and Extreme Lite.

Why do listings show sizes like 75B instead of 34B?
Because 75B is the EU label, and most Triaction stock sits in EU sized markets. The brand’s chart pairs EU 75 with a US 34 band, and the cup letter stays in the EU sequence, so convert the band by the chart and the cup by counting steps from D.

The Bottom Line

A triumph triaction sports bra makes sense for a US reader in a narrow, clear situation: you want a sports bra fitted like a real bra, in graded cups rather than alpha sizes, you are curious about engineering the US market does not offer, above all the Magic Motion’s silicone wire, and you accept an EU sized import to get it. The range’s strengths are its architecture and its honesty about testing: bounce control classes set by a university research group, a wired minimiser that reaches fuller cups, and a wirefree flagship with a genuine Amazon US footprint. Its weakness for US shoppers is purely the route: one listed style, no US storefront, and returns that cross an ocean. Shop it by style number, convert your size from the brand’s chart, and order one bra first.