· 5 min read
How to Start a Gym and Activewear Line: Fabrics, Construction and Manufacturing from 10 Pieces
To start an activewear line, pick a narrow first range, choose performance fabric by its fibre blend and weight, insist on flatlock seams and a squat-tested sample, and launch with a small run. Custom gym wear is manufactured from 10 pieces per style, with samples in 7–10 days and bulk in 2–3 weeks. Here is what to specify and what to test.
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In short
To start an activewear line, pick a narrow first range, choose performance fabric by its fibre blend and weight, insist on flatlock seams and a squat-tested sample, and launch with a small run. Custom gym wear is manufactured from 10 pieces per style, with samples in 7–10 days and bulk in 2–3 weeks. Here is what to specify and what to test.
The short answer: start with three to five styles rather than a full collection, choose fabric by fibre blend and weight rather than by marketing name, and judge the manufacturer on a physical sample that you squat, stretch, sweat in and wash. Custom gym and activewear is manufactured from 10 pieces per style (best per-unit pricing from 20), with a sample in 7–10 days and bulk production in 2–3 weeks. Fabric is where most new activewear brands go wrong, so that is where to spend your attention.
What should a first activewear range include?
A focused first drop sells better and costs less to develop than a wide one.
| Brand type | A sensible first range |
|---|---|
| Gym or studio merchandise | Training tee, shorts, hoodie |
| Women's activewear label | Leggings, sports bra, cropped or fitted top |
| Men's training label | Performance tee, training shorts, joggers, stringer or tank |
| Combat sports brand | Rash guard, fight shorts, training tee |
Each style needs its own pattern and sample, so every extra style adds development cost before you have sold anything. Launch narrow, see what sells, then extend. MOQs explained shows how to plan quantities.
Which fabrics are used for activewear?
| Fabric | Typical blend | Character | Used for |
|---|---|---|---|
| Polyester-elastane jersey | About 85–90% polyester, 10–15% elastane | Durable, quick-drying, colour-fast, takes sublimation | Leggings, rash guards, compression wear |
| Nylon-elastane | About 75–80% nylon, 20–25% elastane | Softer, smoother, more "buttery", more expensive | Premium leggings and sports bras |
| Polyester mesh and micro-mesh | 100% polyester | Light and highly breathable | Training tees, panels, basketball shorts |
| Polyester interlock | 100% polyester | Smooth, stable, moisture-wicking | Performance tees, shorts |
| Cotton-elastane jersey | About 95% cotton, 5% elastane | Soft and natural, but holds sweat | Lifestyle and yoga pieces |
| Woven stretch polyester | Polyester with a little elastane | Light, crisp, quick-drying | Running and fight shorts |
Elastane is the same fibre as spandex; Lycra is a brand of it.
What fabric weight should you use?
| Garment | Typical weight |
|---|---|
| Training tees and tanks | 130–160 GSM |
| Shorts (knit) | 150–200 GSM |
| Sports bras | 220–280 GSM, often double-layered |
| Leggings | 220–300 GSM |
| Compression tops and rash guards | 200–250 GSM |
For leggings, weight and knit density decide whether the fabric stays opaque when stretched. Lighter fabrics feel cooler but are more likely to turn see-through. See the GSM guide for how weight is measured.
Which construction details matter?
- Flatlock seams lie flat against the skin and prevent chafing; they are the standard for leggings and compression wear.
- A gusset — a diamond or triangular panel at the crotch — spreads stress across four seams instead of one and improves fit and durability.
- Four-way stretch fabric stretches and recovers both across and along the garment.
- Waistband construction — a wide, double-layer waistband stays up without digging in; add an internal drawcord for high-intensity training.
- Bonded or covered elastic at leg and arm openings prevents rolling.
- Pockets — a hidden waistband pocket or zipped pocket is a selling point.
How do you test an activewear sample?
- Squat test — put the leggings on, squat in bright light in front of a mirror, and check for transparency.
- Stretch and recovery — stretch the fabric firmly, release, and see whether it returns to shape immediately.
- Wear test — train in it. Check for waistband roll, seams that rub and fabric that rides up.
- Sweat test — look for visible sweat patches in lighter colours.
- Wash test — wash and dry it several times; check for pilling, colour loss, shrinkage and cracking of prints.
- Seam test — pull the seams at the crotch and underarm firmly. Stitching should not pop.
Our guide to sample types has a general checklist to use alongside these.
How do you brand activewear?
- Sublimation for all-over prints and panels on polyester: the colour is dyed into the fabric, so there is nothing to crack or peel.
- Heat transfer and DTF for logos on stretch fabric, including reflective and silicone finishes.
- Screen printing with stretch additive for simple logos.
- Tagless neck prints instead of sewn labels, which can irritate during training.
- Woven or jacquard elastic waistbands carrying your brand name.
Embroidery is best kept to hoodies, caps and joggers; on thin stretch fabric it can pucker and rub.
Where should activewear be made?
Be realistic about what each manufacturing region does best. Pakistan is strong in sublimated polyester sportswear, cotton-rich training wear, hoodies, joggers and combat sports apparel, at low minimums. Many high-end nylon-elastane and specialist technical fabrics are milled elsewhere and imported, which can affect price and availability. Ask any manufacturer where the fabric comes from and get swatches before you commit. See Pakistan vs China vs Bangladesh vs Turkey for a fuller comparison.
What does the process look like?
| Stage | Time |
|---|---|
| Quote | Within 24 hours |
| Design mockups | A few days; free |
| Pre-production sample | 7–10 days |
| Bulk production | 2–3 weeks after sample approval |
| Express delivery | 3–7 days worldwide |
Starting your line with SeamFoundry
We manufacture custom gym and activewear from 10 pieces per style, with sizes mixed freely, your labels and your packaging, plus hoodies and joggers to complete a range. Send your styles, fabric preference and quantity through the quote form for a quote within 24 hours. Gym owners and fight brands can also read the guide for gyms and fight brands.
