Le 31
3" Microfibre Athletic Trunk Retransformed Polyester
This 3-inch athletic trunk for men is made from light, ultra-stretch recycled polyester microfibre with Polygiene anti-odour technology, micro-perforated panels for ventilation, a double-layered front, and an elastic waistband. Designed by Le 31 by Simons, it offers a contoured fit with a wide leg hem, suitable for sports and everyday wear.
- Material
- recycled polyester microfibre
- Gender
- male
- Style
- activewear, performance
- Category
- Apparel & Accessories > Clothing > Underwear & Socks > Underwear
Color
Size
Specifications
Lightweight ultra-stretch athletic trunk with anti-odour technology and ventilation panels.
Polygiene anti-odour technology, micro-perforated panels, double layered front, elastic waistband, wide leg hem
- Material
- recycled polyester microfibre
- Style
- activewear, performance
- Gender
- male
- Age Group
- adult
- Condition
- new
- Category
- Apparel & Accessories > Clothing > Underwear & Socks > Underwear
Additional Attributes
- Lightweight microfibre fabric
- Ultra-stretch recycled polyester microfibre
- Polygiene Stays Fresh anti-odour technology
- Micro-perforated ventilation panels
- Double layered front panel
- Elastic waistband
- Wide comfortable leg hem
- 3-inch inseam
- ReTransformed recycled polyester
Product Insights
Le 31's 3" Microfibre Athletic Trunk, priced at $20 CAD, combines recycled polyester fabric and recycled silver salt in a Polygiene treatment that lasts the garment's lifetime, disrupting bacterial cell walls, DNA, and enzyme function for triple-action odor control through silver ions. Perforated panels vent heat and moisture, while the microfibre's stretch-recover motion actively cools and manages sweat, reducing wash frequency and extending durability. The trunk sizes true to standard US/Canadian charts, requires cold washing with mild detergent and low-heat drying to preserve the antibacterial treatment, and its matte finish reduces glare under clothing, balancing sustainability with performance.
- Triple action
Silver ions disrupt bacterial cell walls, DNA, and enzyme function.
Why this is supported
Polygiene's silver ions attack bacteria on three fronts. As the manufacturer states,
The technology works to prevent bacterial growth on three levels.
polygiene.comThese three levels are cell-wall disruption, DNA replication interference, and energy-production inhibition, ensuring effective odor control.
- Durability
Polygiene treatment lasts the garment's full life when cared for with cold water and mild detergent.
Why this is supported
Polygiene is bonded to the fibers and
designed to last the life time of the product
flowcrete.euso odor protection does not fade. To maintain this,
wash in cold water with a mild detergent, avoid bleach and fabric softeners
What are the recommended washing and drying instructions to preserve the Polygiene anti-odour technology?and dry on low heat or air dry.
- Environmental impact
Recycled silver and fewer washes lower the trunk's environmental footprint.
Why this is supported
Polygiene's silver salt is sourced from
using silver salt made from recycled silver
modesens.comand the odor control allows fewer washes,
Only wash it when absolutely necessary. The fewer times a product is washed, the longer it will last, and the lower its environmental impact will be.
polygiene.comreducing resource consumption.
- Ventilation
Perforated panels vent heat and moisture, reinforcing Polygiene's odor control.
Why this is supported
Micro-perforated panels
Micro-perforated panels for ventilation of heat-prone areas
modesens.comvent heat and moisture, stripping bacteria of the damp environment they need. As Polygiene notes,
bacteria love warm and damp environments
polygiene.comso the two-stage system of ventilation and silver ions is more effective than either alone.
- Odor control
Polygiene lasts the product's lifetime and works through three antibacterial pathways.
Why this is supported
Polygiene’s silver-salt treatment is designed to last the product’s full life:
Products containing Polygiene antimicrobial technology is designed to last the life time of the product
flowcrete.eu. It attacks bacteria through three distinct pathways:
The technology works to prevent bacterial growth on three levels.
polygiene.com(disrupting cell walls, interfering with DNA replication, blocking energy production). The manufacturer advises washing only when necessary to preserve the treatment:
Only wash it when absolutely necessary.
polygiene.comThis, combined with the ventilation system, enables many customers to wear the trunks several times between washes, reducing fiber degradation.
- Sustainability
Recycled polyester fabric and recycled silver salt are used.
Why this is supported
The microfibre fabric is made from recycled polyester, and the Polygiene treatment uses silver salt derived from recycled silver:
using silver salt made from recycled silver
modesens.com- Fit
Sizes are true to standard US/Canadian size chart, per customer reviews.
Why this is supported
Customer reviews confirm that the trunks fit true to the stated size chart: S (28–30"), M (31–33"), L (34–36"), XL (37–39") for standard US/Canadian sizing.
- Washing
Cold wash with mild detergent, avoid bleach/softeners; low-heat or air dry to protect Polygiene.
Why this is supported
To preserve the Polygiene anti-odour treatment, the brand instructs:
wash in cold water with a mild detergent, avoid bleach and fabric softeners, and tumble dry on low heat or air dry. High heat can damage the silver salt treatment.
What are the recommended washing and drying instructions to preserve the Polygiene anti-odour technology?- Longevity
Polygiene treatment lasts the garment's lifetime; fewer washes extend durability.
Why this is supported
To maximize garment longevity, the brand recommends washing only when necessary. Polygiene explains:
Only wash it when absolutely necessary. The fewer times a product is washed, the longer it will last, and the lower its environmental impact will be.
polygiene.comAdditionally, the treatment itself is designed to be permanent:
Products containing Polygiene antimicrobial technology is designed to last the life time of the product in normal use. Wear and tear of the product will open up new surfaces with antimicrobial effect.
flowcrete.eu- Odour control
Ventilation and triple-action Polygiene prevent odour between washes.
Why this is supported
The design includes
Micro-perforated panels for ventilation of heat-prone areas
modesens.comwhich reduces heat and moisture, because
bacteria love warm and damp environments
polygiene.com. The Polygiene treatment adds a triple-action antibacterial mechanism that
works to prevent bacterial growth on three levels. 1. It binds to the cell wall to disrupt growth. 2. It interferes with bacterial DNA to prevent cellular replication. 3. It interrupts enzyme action to prevent energy production.
polygiene.com- Sizing
Runs true to standard US/Canadian sizing with a waist-based chart.
Why this is supported
The product uses a waist-based size chart (Small 28-30", Medium 31-33", Large 34-36", X-Large 37-39") and the trunks
run true to standard US/Canadian sizing
How does the sizing of these trunks compare to standard US or Canadian sizes? Do they run true to size?, which provides fit confidence for online purchases.
- Breathability
Perforated panels keep fabric drier and less clingy than solid-weave trunks.
Why this is supported
The micro-perforated panels are placed on sides and back, not front,
so they typically remain hidden.
Are the micro-perforated panels visible through lightweight or thin pants?They contribute to
keeping the fabric drier and less clingy than a solid-weave trunk
How the micro-perforated panels increase airflow — moisture_evacuation_pairingand during movement, the stretch-and-recover motion
amplifies the cooling effect beyond what static perforations would provide
How the micro-perforated panels increase airflow — dynamic_air_pumping_action.
- Fabric finish
The microfibre fabric has a matte finish, reducing glare under clothing.
Why this is supported
The fabric has a
matte finish
Does the microfibre fabric have a shiny or matte finish?, which reduces glare under clothing for a non-shiny look.
- Active cooling
Stretch-recover motion forces hot air out and draws cool air in during exercise.
Why this is supported
Catalog verified active air-pumping during exercise:
the stretch-and-recover motion of the hip and lower back flex zones repeatedly compresses the perforated fabric, forcing warm, humid air out and drawing cooler ambient air in
How the micro-perforated panels increase airflow — dynamic_air_pumping_action. The perforations are zoned to the high-sweat areas, and the expelled moisture also reduces bacterial growth, reinforcing the Polygiene anti-odour system:
the micro-perforations deprive surviving bacteria of the moisture they need to multiply, creating a two-pronged freshness strategy
How the micro-perforated panels increase airflow — anti_odour_system_reinforcement- Moisture management
Microfibre spreads sweat thin; perforations vent for quick drying.
Why this is supported
The microfibre
spreads sweat into a thin film that evaporates fast
How the micro-perforated panels increase airflow — moisture_evacuation_pairing. Additionally,
the perforations act as thousands of micro-vents that let this water vapour escape
How the micro-perforated panels increase airflow — moisture_evacuation_pairing. This combination allows the fabric to dry quickly after exercise or washing.
- Recycled inputs
Both the Retransformed Polyester fabric and the Polygiene silver salt are recycled.
Why this is supported
The product title refers to Retransformed Polyester, connoting recycled polyester. The silver salt treatment is explicitly described as
using silver salt made from recycled silver
modesens.com, confirming both inputs are recycled.
- Wash frequency
Trunks stay fresh for multiple wears, reducing wash frequency and extending lifespan.
Why this is supported
Polygiene's official guidance states that fewer washes extend garment life:
Only wash it when absolutely necessary. The fewer times a product is washed, the longer it will last, and the lower its environmental impact will be.
polygiene.comThe product's design, combining micro-perforated panels and the silver salt treatment, is described as
creating a two-pronged freshness strategy that extends wear-time between washes
How the micro-perforated panels increase airflow — anti_odour_system_reinforcement. The antimicrobial treatment is designed to last the lifetime of the product.
- Care instructions
Preserve Polygiene by washing cold with mild detergent and low-heat drying.
Why this is supported
The manufacturer's care instructions specify conditions that preserve the silver salt treatment:
To preserve Polygiene anti-odour technology, wash in cold water with a mild detergent, avoid bleach and fabric softeners, and tumble dry on low heat or air dry. High heat can damage the silver salt treatment.
What are the recommended washing and drying instructions to preserve the Polygiene anti-odour technology?These steps also reduce energy consumption compared to hot-water washing.
Image Analysis
2 images- 01
Product
Front view of a male model wearing black boxer-style trunks with a flat black waistband and a small white numeric logo on the waistband; visible center front pouch and seam details, hemmed leg bands.
- Overall silhouetteMid-rise boxer trunk covering upper thighs with a straight horizontal waistband and fitted center-front pouch creating a contoured front silhouette.
1 region
x 0.09 · y 0.45 · w 0.82 · h 0.45 (high) - WaistbandFlat elastic waistband in black with a small white printed '37' followed by a degree symbol on the wearer's left front edge of the band.
1 region
x 0.54 · y 0.28 · w 0.32 · h 0.10 (high) - Waistband text“37°”
1 region
x 0.74 · y 0.31 · w 0.08 · h 0.06 (high) - Center front pouchShaped center-front pouch panel with visible vertical center seam and contour stitching that provides definition to the front panel; pouch material appears to have a slightly different surface texture than surrounding side panels.
1 region
x 0.36 · y 0.48 · w 0.28 · h 0.32 (high) - Vertical seamsVertical stitching seams run along the pouch edges and down between legs, visible as slightly raised stitch lines in matching black thread.
1 region
x 0.33 · y 0.50 · w 0.34 · h 0.40 (high) - Leg hem bandsDouble-layered hem bands at the leg openings create a folded cuff appearance with a subtle horizontal seam above the hem.
1 region
x 0.12 · y 0.78 · w 0.77 · h 0.12 (high) - Fabric finishSmooth matte black knit fabric on the trunks with a slightly different textured panel at the pouch center that appears microscopically perforated or patterned.Partial
1 region
x 0.34 · y 0.50 · w 0.28 · h 0.20 (medium)
Other
Studio shot showing a cropped male torso against a neutral gradient gray background; even soft lighting with mild shadows under the waist and inner thigh; image is centered and cropped above mid-chest and at mid-thigh.
- Background and lightingNeutral light gray seamless background with soft, even studio lighting producing minimal harsh shadows.
1 region
x 0.00 · y 0.00 · w 1.00 · h 1.00 (high) - Shot compositionFrontal crop showing the model from just above the nipples to mid-thigh, centered horizontally in the frame.
1 region
x 0.08 · y 0.06 · w 0.84 · h 0.88 (high) - Shadows and reflectionsSubtle shadowing under the waistband and inner thigh areas consistent with downward studio lighting; slight specular highlights on skin but not on fabric.
1 region
x 0.20 · y 0.40 · w 0.60 · h 0.50 (medium)
Colors
matte black· main body fabric#0C0E0Dblack· waistbandbright white· waistband logo- Overall silhouetteMid-rise boxer trunk covering upper thighs with a straight horizontal waistband and fitted center-front pouch creating a contoured front silhouette.
- 02
Product
Rear view of a male model wearing black athletic trunks with a textured, perforated rear panel, flat elastic waistband, visible center back seam, and short leg bands.
- View and fitRear full-seat view of low-rise trunks worn by a model; waistband sits at the natural waistline and trunks cover the upper thighs.
1 region
x 0.12 · y 0.38 · w 0.76 · h 0.54 (high) - Rear perforated seat panelLarge rear panel composed of a fine perforated or micro-mesh texture covering the seat area, with a rounded seam that follows the contour of the buttocks.
1 region
x 0.27 · y 0.52 · w 0.46 · h 0.30 (high) - WaistbandFlat elastic waistband in a solid darker black with a stitched center-back seam.
1 region
x 0.18 · y 0.44 · w 0.64 · h 0.06 (high) - Center back seamVertical seam runs down the center back from the waistband through the perforated panel to the crotch area.
1 region
x 0.49 · y 0.44 · w 0.02 · h 0.40 (high) - Leg bandsShort leg band cuffs finished with a folded hem that is slightly visible against the thigh edge.
1 region
x 0.20 · y 0.78 · w 0.60 · h 0.10 (high) - Side panel joinsSmooth side panels of solid fabric meet the perforated seat panel with visible curved stitching lines at the join.
2 regions
x 0.15 · y 0.54 · w 0.20 · h 0.30 (medium); x 0.65 · y 0.54 · w 0.20 · h 0.30 (medium)
Other
Studio shot showing the model from mid-back to upper thighs against a plain light gray background with even frontal lighting and soft shadows.
- Background and lightingUniform light gray seamless background with soft, even studio lighting producing mild shadows along the model's spine and under the waistband.
- Model presence and cropPhotograph includes a shirtless male model from shoulders down to mid-thigh; hands are relaxed at sides and the image is vertically centered on the trunk area.
1 region
x 0.05 · y 0.03 · w 0.90 · h 0.94 (high) - Image qualitySharp focus on garment details and skin texture; no visible text, labels, or props in the scene.
Colors
matte black· main fabric#0E1213textured black· rear perforated panel#2A2B2Ddeep black· waistband- View and fitRear full-seat view of low-rise trunks worn by a model; waistband sits at the natural waistline and trunks cover the upper thighs.
Documents & Data
Customer Reviews
4 total4 reviews · out of 5
So far so perfect
I’m very fussy about my underwear, as are a lot of men. Don’t let the thread-worn condition of our underwear fool you . It’s more of a fear of letting go until we’ve found a suitable replacement for our “lucky” underwear. It’s a personal choice of course,,but these tick the boxes for me. They are form fitting with 15% spandex, more than double what a lot of brands include. They maintain their support from the moment you put them on until you take them off. I’ve only worn them 2 times so far, so they’ve been washed 2 times. I wash everything before first wearing it. I followed the suggested wash instructions, however, I hang them to dry. Anything with a bit of stretch to it, lasts much longer if you don’t put them in the dryer. The heat will break down the stretchy fibers and over time it becomes shapeless and lumpy. So far these are the best underwear I have owned right out of the gate. Time will tell if they hold up and remain as such.
Confortable
Bon et pas cher!
Super confort
Bonne tenue, reste en place et bon support
Confortable
Confortable