Ironroot Performance New Zealand: Gym and Strength Training Line Comparison Test
Ironroot Performance is a New Zealand-based brand whose gym and strength training line is one of its most demanding programmes. We tested the new recycled nylon interlock against the fabric Ironroot Performance used last season. Both were made into identical garments and evaluated side by side for gym and strength training line.

Ironroot Performance: Recycled Nylon Interlock in use during resistance training and circuit work
Evaluation background
The programme covers leggings, training tops and shorts, used for resistance training and circuit work. The environment is short bursts of high load against equipment surfaces and the requirement written into the brief was squat-proof coverage with recovery after repeated stretch. Fabric was selected on that basis rather than on price alone.
Fabric under evaluation
| Parameter | Value |
|---|---|
| Fabric | Recycled Nylon Interlock |
| Composition | 78% GRS recycled nylon / 22% spandex |
| Weight | 270 GSM |
| Width | 175 cm |
| Primary function | stays fully opaque under tension while carrying a recycled claim |
| Target | opacity above 96% at 30% extension |
| Test method | AATCC 183 |
| Additional note | GRS chain of custody documents |
| Certification | OEKO-TEX Standard 100 |

Recycled Nylon Interlock close-up showing the fabric surface
What was compared
Construction, weight and colour were held constant. The only difference was the fabric, which is the only way a comparison tells you anything useful.
Laboratory comparison
The new fabric reached opacity above 96% at 30% extension against AATCC 183, while the previous material missed the same target. Comfort measurements were closer, which is expected because hand had already been approved.

Evaluation session with the Ironroot Performance team
Wear comparison
Over four weeks the difference appeared during short bursts of high load against equipment surfaces. Wearers described the new version as cleaner and lighter in use, even though the scales said the two garments weighed the same.
Cost comparison
The upgrade adds a modest amount per garment. Measured against the return rate of the previous season, the change pays for itself within a single drop.

Test records and inspection notes for the Gym and Strength Training Line
Scorecard
| Criterion | Result |
|---|---|
| Function | 4.7 / 5 |
| Comfort | 4.4 / 5 |
| Durability | 4.8 / 5 |
| Appearance | 4.6 / 5 |
| Cost efficiency | 4.5 / 5 |
“Our athletes noticed the difference in the first week, and the test data explained why.” — Ironroot Performance Technical Team

Packed bulk rolls before shipment to New Zealand
Verdict and recommendation
The new recycled nylon interlock outperformed the previous fabric on every measured criterion and we recommend switching the whole programme over. For Ironroot Performance the practical next steps are to keep the current specification for the repeat, retain the shade standard, and issue AATCC 183 results with every lot so any claim can be supported with data.