Custom Running and Gym Shorts: Fabric Weight, Liners, and Bulk Order Specs

Running and gym shorts look like a simple product until you try to specify one for bulk production. The difference between a short that survives a marathon training block and one that falls apart after ten washes comes down to three decisions buyers often leave to the manufacturer by default: fabric weight, liner type, and waistband construction.

Fabric weight and breathability

Running shorts are typically cut from lightweight polyester or polyester-spandex blends between 120 and 160 GSM. Lighter fabric breathes better and dries faster, which matters for anything worn during sustained cardio. Gym shorts used for weight training rather than running can go slightly heavier, up to 180 to 200 GSM, since durability under equipment contact matters more than moisture-wicking speed.

Mesh paneling at the sides or back is common on running-specific shorts to add ventilation without adding weight across the whole garment.

Liner options: mesh brief vs none

This single spec decision affects both cost and how the product gets used.

• Built-in mesh brief liner lets the short function as standalone activewear, which is what most running brands specify. It adds a small per-unit cost but removes the need for separate base layers.
• No liner keeps the short lighter and cheaper, aimed at buyers who wear compression shorts or leggings underneath. Common for team training shorts worn over compression layers.

Specify this explicitly. Manufacturers will default to one or the other based on the product category, and it may not match what your customer expects.

Waistband construction

Three approaches are common, each suited to a different use case:

• Elastic only — simplest, cheapest, fine for casual gym wear
• Drawcord only — used less often alone, mainly on looser training shorts
• Elastic with internal drawcord — the standard for performance running shorts, since it holds during motion without needing to be pulled tight

Reflective detailing

For brands targeting outdoor runners, reflective piping or logo placement is a low-cost addition that reads as a serious performance detail rather than a decorative one. It is typically added via heat-transfer reflective tape at the hem or side seam and should be specified at the design stage since it affects the cutting pattern.

Sizing and fit for bulk orders

Running and gym shorts are ordered across wider size ranges than most apparel categories because they serve both performance and casual buyers. Confirm your size chart against your actual customer base rather than accepting a generic size run, and request a sample in your most-ordered size before committing to bulk production.

Get a quote for your specific order

Asons Impex produces running and gym shorts in lightweight performance fabric with mesh liner options from Sialkot, Pakistan. Minimum order is 20 units per design. Lead time is 15 to 20 working days from sample approval. Send your design reference to info@asonsimpex.com for a quote.