INNER SELF
Corecotton™ Muscle T-Shirt
This sleeveless muscle T-shirt from the INNER SELF Montreal collection is a running top made from 100% cotton jersey. It features a crew neckline, raw cut sleeves, and reflective logo and patterns on the back for visibility. Designed for athletic use, it offers a fitted silhouette with wide armholes for mobility.
- Material
- 100% cotton jersey
- Style
- casual, activewear, sporty
- Category
- Apparel & Accessories > Clothing > Activewear
Color
Size
Specifications
Lightweight cotton muscle t-shirt designed for running, featuring reflective details and raw cut sleeves.
Raw cut sleeves, reflective logo and patterns, 100% cotton jersey
- Material
- 100% cotton jersey
- Style
- casual, activewear, sporty
- Occasion
- workout
- Gender
- male
- Age Group
- adult
- Condition
- new
- Category
- Apparel & Accessories > Clothing > Activewear
Additional Attributes
- 100% cotton jersey fabric
- lightweight construction
- raw cut sleeves
- reflective star logo on back
- reflective patterns
- signature running top
- muscle t-shirt silhouette
- sleeveless design
- comfortable for running
- maximum comfort performance
Product Insights
The Corecotton™ Muscle T-Shirt by INNER SELF is a lightweight 4-5 oz 100% cotton jersey tank with raw-cut sleeves and hem that maximize ventilation, freedom of movement, and an athletic silhouette, but requires sizing up due to 3-5% shrinkage on hot wash and careful washing to preserve the reflective star logo and slow edge curling; it is an exclusive Simons capsule designed for runners, offering a tradeoff between breathable comfort for light activity and sweat absorption during intense workouts.
- Sizing
Size up if between sizes; 100% cotton shrinks 3-5% on first hot wash.
Why this is supported
The product does not specify pre-shrunk fabric, so shrinkage is expected.
100% cotton jersey typically shrinks 3-5% after the first hot wash.
How much will this t-shirt shrink after the first wash, and should I size up?For this reason, the Q&A recommends
sizing up if you are between sizes or prefer a looser fit after washing.
How much will this t-shirt shrink after the first wash, and should I size up?To minimize shrinkage and preserve the raw-cut edge, wash inside out on a gentle cycle and air dry.
- Fit
Wide armholes and raw sleeves maximize ventilation and freedom of movement.
Why this is supported
The muscle tank silhouette is defined by
The armhole edge is raw-cut, meaning it
sits completely flat without the restrictive casing of a traditional hem
Muscle tank fit and sizing guide — raw_cut_sleeves. Combined,
, providing
breathability and freedom of movement that t-shirts can't match
tshirtelephant.com. This results in an intentionally looser fit through arms and torso compared to a standard slim-fit tank.
- Fabric weight
Light 4–5 oz cotton jersey hangs with minimal weight even when sweaty.
Why this is supported
The product page describes the cotton as 'light', and deep research places its weight at
4–5 oz/yd²
Fabric weight, feel, and breathability — light_cotton_jersey_weight. This light jersey hangs with minimal weight even when sweaty, avoiding the pull or slap of heavier cotton during movement.
- Mobility
Raw cut sleeves reduce chafing and tension for easier overhead lifts.
Why this is supported
The raw cut edge
sits completely flat without the restrictive casing of a traditional hem
Muscle tank fit and sizing guide — raw_cut_sleevesaccording to the fit guide, which
reduces any tension around the underarm and shoulder
Muscle tank fit and sizing guide — raw_cut_sleeves, minimizing fabric drag during overhead movements.
- Aging
Raw cut edges curl gently with wear; wash inside out to slow fraying.
Why this is supported
The fit guide notes that
the edge will develop a soft, rolled curl — an aesthetic that yields a lived-in, effortless look distinct from a crisp, finished tank.
Muscle tank fit and sizing guide — raw_cut_sleevesHowever, the Q&A adds that
Raw cut sleeves are designed to be unfinished and may experience some fraying over time, especially with machine washing and drying. To minimize fraying, wash the shirt inside out on a gentle cycle and air dry.
Will the raw cut sleeves unravel or fray after multiple washes?- Styling
Raw hem anchors an athleisure outfit with biker shorts and sneakers.
Why this is supported
A styling guide from sewmamasew.com suggests
Go for a slightly slouchy cotton muscle tank in heather grey or washed black with a raw hem, and pair it with high-waisted black biker shorts that hit mid-thigh.
sewmamasew.comThis illustrates the raw hem's role in a sporty-street look.
- Ventilation
Unhemmed sleeves maximize side ventilation for cooling during runs.
Why this is supported
The fabric and design guide reports that the raw cut sleeves
maximize side ventilation, allowing air to flow directly across the ribcage and back — a design feature that amplifies evaporative cooling even though the cotton jersey lacks synthetic wicking
Fabric weight, feel, and breathability — raw_cut_sleeves_muscle_tee_silhouette, making the shirt suitable for warm-weather performance.
- Moisture handling
Lightweight 4-5 oz 100% cotton jersey absorbs sweat but minimizes slapping and enhances cooling via raw-cut armholes.
Why this is supported
Cotton jersey is not moisture-wicking—it absorbs sweat and becomes heavy during intense workouts. This top is best for low-impact activities or casual wear rather than high-sweat training sessions.
Does the cotton jersey effectively wick moisture, or does it become heavy with sweat during workouts?Despite this, the 4-5 oz light cotton jersey weight prevents the tank from pulling or slapping against the body even when sweat-saturated, and the raw cut sleeves and deep armholes provide side ventilation that enhances evaporative cooling, partially offsetting the lack of moisture-wicking.
- Safety placement
Reflective star on back improves rear visibility to drivers in traffic.
Why this is supported
The reflective star logo is intentionally placed on the back to maximize visibility to drivers approaching from behind.
By placing the primary reflective logo on the back, the design targets the crucial rear angle where runners are most exposed to vehicle traffic — when headlights hit the star, the retroreflective response creates an early, unmistakable visual cue for drivers, giving them more time to react than if visibility were left to the garment's dark cotton alone.
Reflective print visibility and safety — back_focused_star_logo_placementHowever, the reflective element is a single small logo, so it provides a rear-facing safety cue for low-to-moderate traffic running but is not a substitute for full reflective gear in high-traffic or very low-light conditions.
- Reflective print durability
Cotton jersey grips reflective print well; gentle wash prevents peeling.
Why this is supported
The reflective star print's adhesion to the cotton jersey substrate is rated as good, and its longevity depends on care.
| Cotton jersey | Good | Good | Good | Good | Shrinkage after washing |
asafetyproducts.comAdditionally, the brand advises:
The reflective star logo is applied as a print, and its durability depends on care. Washing inside out on a gentle cycle and avoiding fabric softeners will help prevent peeling. Over time, some wear is normal with frequent machine drying.
How durable is the reflective star logo on the back when machine washed and dried?So while the print adheres well, proper care is essential to prevent peeling and extend its life.
- Brand exclusivity
Exclusive to Simons via i.FiV5; a Montreal-designed capsule from 2024 startup INNER SELF.
Why this is supported
This shirt is part of the Montreal collection available exclusively through Simons' i.FiV5 line.
i. FiV5 by Simons: an exclusive designed in Canada
lyst.comThe i.FiV5 brand name is symbolic—
The name i.fiv5 is symbolic, representing our vision of how people celebrate their achievements. It’s inspired by the high five,
marketingmag.ca—and its visual identity was crafted by Quebec agency Bleu Blanc Rouge.
Quebec department store chain Maison Simons has launched a new sportswear line for men, with a brand identity developed by its agency Bleu Blanc Rouge.
marketingmag.caINNER SELF itself was founded in 2024 in Montreal, as per its LinkedIn profile.
- Moisture management
Buyers report that the cotton fabric holds sweat and becomes heavy during intense workouts.
Why this is supported
A question-and-answer source indicates that the 100% cotton jersey wicks sweat poorly. It can become heavy and uncomfortable during high-sweat training, despite the product's description as a 'signature running top.' Buyers recommend it for low-impact activities or casual use.
- Outfit formula
Styled with high-waisted black biker shorts and retro sneakers for a sporty-street look.
Why this is supported
The recommended outfit formula, sourced from sewmamasew.com, pairs a slouchy cotton muscle tank with high-waisted black biker shorts and retro sneakers:
Go for a slightly slouchy cotton muscle tank in heather grey or washed black with a raw hem, and pair it with high-waisted black biker shorts that hit mid-thigh.
sewmamasew.comThe Corecotton tank's black and emerald green colors are opaque and not sheer under gym lighting, making them suitable for this pairing. The reflective star logo on the back adds a subtle accent for evening use, as the metallic finish catches light during nighttime jogs.
- Care
Inside-out gentle wash and air drying prevent reflective logo peeling and preserve safety visibility.
Why this is supported
The brand's Q&A provides care instructions:
Washing inside out on a gentle cycle and avoiding fabric softeners will help prevent peeling.
How durable is the reflective star logo on the back when machine washed and dried?Industry testing rates cotton jersey's adhesion for reflective prints as good:
| Cotton jersey | Good | Good | Good | Good | Shrinkage after washing |
asafetyproducts.comThe same Q&A warns that
Over time, some wear is normal with frequent machine drying.
How durable is the reflective star logo on the back when machine washed and dried?So air drying is recommended. The 100% cotton jersey also shrinks 3-5% in hot water, further opposing machine drying. Because the reflective logo is the garment's primary low-light safety feature, preventing peeling through correct care directly preserves safety visibility.
- Shrinkage
100% cotton jersey shrinks 3-5% on hot wash; size up if between sizes.
Why this is supported
The shirt is made from 100% cotton jersey that is not pre-shrunk.
100% cotton jersey typically shrinks 3-5% after the first hot wash.
How much will this t-shirt shrink after the first wash, and should I size up?Therefore, customers between sizes should order one size up for a relaxed post-wash fit.
- Movement range
Deep armholes and raw-cut sleeves prevent fabric drag and binding during full arm extension.
Why this is supported
The deep armhole cut
eliminates fabric drag during overhead presses, pull-ups, and full arm extension in a running stride
Muscle tank fit and sizing guide — freedom_of_movement. The raw-cut sleeve
sits completely flat without the restrictive casing of a traditional hem
Muscle tank fit and sizing guide — raw_cut_sleeves, ensuring no tug across the chest when reaching or stretching. The lightweight cotton jersey (4–5 oz/yd²)
light enough that even when saturated with sweat the tank won't pull or slap against the body the way a heavyweight cotton would
Fabric weight, feel, and breathability — light_cotton_jersey_weight, preserving full range of motion during short runs and warm-weather training.
- Silhouette
Oversized armholes deliberately expose shoulders and upper lats for an athletic look.
Why this is supported
The oversized armholes are designed to
Larger armholes that show off shoulders and arms.
tshirtelephant.comThis transforms the shirt into an athletic statement while ensuring the armhole clearance never binds during movement.
- Breathability
Lightweight cotton and deep armholes provide breathability for light activity but not heavy sweating.
Why this is supported
light enough that even when saturated with sweat the tank won't pull or slap against the body the way a heavyweight cotton would
Fabric weight, feel, and breathability — light_cotton_jersey_weightmaximize side ventilation, allowing air to flow directly across the ribcage and back — a design feature that amplifies evaporative cooling even though the cotton jersey lacks synthetic wicking
Fabric weight, feel, and breathability — raw_cut_sleeves_muscle_tee_silhouetteCotton jersey is not moisture-wicking—it absorbs sweat and becomes heavy during intense workouts. This top is best for low-impact activities or casual wear rather than high-sweat training sessions.
Does the cotton jersey effectively wick moisture, or does it become heavy with sweat during workouts?- Brand text
Hidden prints INNER SELF, THE ESSENCE OF FREEDOM, and RUNNING TEAM communicate brand's runner-empowerment mission.
Why this is supported
The chest and back prints embed the brand's runner-empowerment message. The brand states:
Our apparel embodies this philosophy, designed to empower runners to break boundaries and embrace their freedom.
ca.linkedin.comThe 'INNER SELF' print aligns with the brand's name, while 'THE ESSENCE OF FREEDOM' and 'RUNNING TEAM' extend the freedom and community aspects. The brand's mission is further echoed in the i.FiV5 visual platform, which was
inspired by playing fields, both real and imaginary
marketingmag.ca. Together, these details turn the tank into a wearable narrative of empowerment.
- Reflective logo
Reflective star logo on back enhances low-light visibility and symbolizes personal achievement.
Why this is supported
The back reflective star logo serves dual functions. The i.FiV5 brand explains that its visual platform was
inspired by the high five
marketingmag.cagesture symbolizing achievement. Additionally, the back placement enhances safety:
the design targets the crucial rear angle where runners are most exposed to vehicle traffic
Reflective print visibility and safety — back_focused_star_logo_placement. For durability, care is needed:
Washing inside out on a gentle cycle and avoiding fabric softeners will help prevent peeling. Over time, some wear is normal with frequent machine drying.
How durable is the reflective star logo on the back when machine washed and dried?- Exclusive capsule
This tank is part of an exclusive i.FiV5 capsule from the INNER SELF Montreal collection, available only at Simons.
Why this is supported
The INNER SELF Montreal collection is an exclusive capsule for i.FiV5, launched in partnership with and available only at Simons. This limited distribution adds a sense of rarity to the design.
Image Analysis
3 images- 01
Product
Sleeveless black muscle-style T-shirt worn by a kneeling male model, with wide arm openings and a crew neckline; visible front and side of the torso and upper hem are shown.
- SilhouetteSleeveless muscle T-shirt with wide, dropped armholes and a straight hem, fitted across the chest and upper torso in this view.
1 region
x 0.12 · y 0.05 · w 0.76 · h 0.52 (high) - NecklineHigh crew neckline with a narrow collar band visible around the model's neck.
1 region
x 0.52 · y 0.06 · w 0.24 · h 0.14 (high) - Armhole cutLarge open armholes exposing the upper arms and shoulders; inner edge of the armhole follows a smooth curved cut.
2 regions
x 0.18 · y 0.18 · w 0.28 · h 0.28 (high); x 0.46 · y 0.10 · w 0.22 · h 0.22 (medium) - Fabric appearanceMatte, smooth knit fabric without visible pattern or texture at this resolution.
1 region
x 0.20 · y 0.10 · w 0.60 · h 0.40 (medium) - Visible hemLower hem of the T-shirt is visible over the upper thigh area on the left side of the image.
1 region
x 0.10 · y 0.40 · w 0.40 · h 0.22 (high) - Neck accessory on garment viewThin chain necklace worn by the model sits on top of the T-shirt and follows the neckline curve.
1 region
x 0.50 · y 0.13 · w 0.28 · h 0.14 (high)
Other
Studio lifestyle shot of a kneeling male model on a pale gradient background with soft directional lighting and visible props including shoes and socks; image shows soft shadowing to the lower left.
- Pose and compositionMale model is kneeling with one knee on the ground and hands on the floor in a dynamic runner-like pose, occupying central and lower image areas.
1 region
x 0.06 · y 0.30 · w 0.88 · h 0.64 (high) - Background and lightingSmooth studio gradient background shifting from pale pink to very light beige with even soft lighting and gentle shadows beneath the model.
- Footwear and propsChunky cream-colored sneakers and white crew socks are visible on the model; shoes rest on the studio floor and are part of the scene but not described as the primary product here.
2 regions
x 0.04 · y 0.62 · w 0.30 · h 0.34 (high); x 0.62 · y 0.62 · w 0.32 · h 0.30 (high) - Image qualitySharp focus on the model and garments with natural skin detail and no visible compression artifacts.
Colors
deep black· T-shirt body#12161Cdeep black· shorts#12161C- SilhouetteSleeveless muscle T-shirt with wide, dropped armholes and a straight hem, fitted across the chest and upper torso in this view.
- 02
Product
Black sleeveless muscle T-shirt shown on a model from chest-up, with a ribbed crew neckline, wide cut armholes, and a small white chest print reading INNER SELF.
- NecklineRibbed crew neck with visible fine rib stitching, sits close to the base of the model's neck.
1 region
x 0.18 · y 0.22 · w 0.38 · h 0.10 (high) - Armhole styleWide sleeveless cut with the shoulder seam removed or trimmed to create a large arm opening showing the model's upper arm.
1 region
x 0.62 · y 0.34 · w 0.33 · h 0.45 (high) - Fabric appearanceSmooth, matte knit fabric with even surface and no visible texture or pattern.
1 region
x 0.08 · y 0.34 · w 0.54 · h 0.55 (high) - Chest print“Small uppercase text printed on the left chest area reading INNER SELF in white.”
1 region
x 0.43 · y 0.52 · w 0.16 · h 0.06 (high) - Shoulder seam finishEdge of the sleeve opening appears turned or narrowly hemmed with a clean stitch line along the shoulder cut.
1 region
x 0.62 · y 0.30 · w 0.20 · h 0.12 (medium)
Other
Studio shot of a model against a plain light background, cropped at mid-torso and including the model's head and right arm; even soft lighting with minimal shadows.
- Shot compositionPortrait-oriented crop showing upper torso and head of a standing model angled slightly to the viewer's left.
- Background and lightingSmooth, light neutral wall background with soft diffuse lighting producing gentle shadows at the shirt's left side.
1 region
x 0.00 · y 0.00 · w 1.00 · h 1.00 (high) - Visible model featuresModel's head and right upper arm are visible; skin and facial features are clearly shown and not part of the product description.
2 regions
x 0.12 · y 0.03 · w 0.60 · h 0.45 (high); x 0.62 · y 0.34 · w 0.33 · h 0.45 (high)
Colors
deep black· main fabric#0D0D0Ebright white· printed chest text- NecklineRibbed crew neck with visible fine rib stitching, sits close to the base of the model's neck.
- 03
Product
Rear view of a sleeveless black muscle T-shirt on a model; back has a large silver/grey cross-shaped graphic, a smaller matching cross above it, and a two-line text block near the lower back.
- SilhouetteSleeveless muscle T-shirt shown from the back with wide arm openings and a crew neckline; straight hem falls just above the model's top of hips.
1 region
x 0.14 · y 0.10 · w 0.72 · h 0.69 (high) - Large back graphicVertical and horizontal elongated cross graphic in a silver/grey tone, centered on the upper-to-mid back; vertical arm extends above and below the horizontal arm.
1 region
x 0.34 · y 0.20 · w 0.32 · h 0.40 (high) - Small upper crossSmaller, similar silver/grey cross motif positioned to the right and slightly above the large cross.
1 region
x 0.60 · y 0.16 · w 0.12 · h 0.12 (high) - Lower-back text line 1“THE ESSENCE OF FREEDOM”
1 region
x 0.34 · y 0.61 · w 0.32 · h 0.05 (high) - Lower-back text line 2“© RUNNING TEAM”
1 region
x 0.39 · y 0.66 · w 0.24 · h 0.04 (high) - Fabric appearanceJersey-knit fabric with a matte finish visible on the back panel; fabric hangs straight without visible stretch lines.
1 region
x 0.22 · y 0.18 · w 0.56 · h 0.55 (high) - Neckline bindingNarrow ribbed crew neckline binding in the same black fabric as the body.
1 region
x 0.34 · y 0.10 · w 0.32 · h 0.06 (high) - Arm opening finishRaw or minimally hemmed wide arm openings revealing the model's shoulders and upper arms.
2 regions
x 0.14 · y 0.16 · w 0.12 · h 0.38 (high); x 0.74 · y 0.16 · w 0.12 · h 0.38 (high)
Other
Studio rear-view product shot on a standing model against a plain light background; even soft lighting with minimal shadows; image cropped to include model from head to mid-thigh.
- Shot compositionRear three-quarter framed shot of a standing male model, centered vertically and horizontally with the shirt as the focal point.
- BackgroundUniform light grey to off-white studio background without props or textures.
1 region
x 0.00 · y 0.00 · w 1.00 · h 1.00 (high) - LightingSoft, even studio lighting producing minimal shadows and even color across the garment and model.
- Crop and framingImage is cropped to show the model from just above the head to mid-thigh; lower legs are not visible.
1 region
x 0.00 · y 0.00 · w 1.00 · h 1.00 (high)
Colors
deep black· body#0D0D0Esilver grey· back graphic#A5AAADbright white· lower-back text- SilhouetteSleeveless muscle T-shirt shown from the back with wide arm openings and a crew neckline; straight hem falls just above the model's top of hips.