SEASONAL
Which Pullover Weight to Buy
October 17, 2026 · Alo Editorial · 8 MIN READ
The reason weight matters more in autumn than at any other time is the compression of the indoor-outdoor gap. In July you are choosing for one temperature. In October you are choosing for a range, and a pullover that is correct for the walk to the studio may be far too warm for the studio itself....
Pullover weight is not on any size chart, which is why people buy the wrong one. A midweight and a heavyweight pullover are not the same garment in two thicknesses. They are two different garments, designed for two different indoor environments, and buying the wrong one is the single most common reason an autumn pullover ends up in the back of the wardrobe by November.
The reason weight matters more in autumn than at any other time is the compression of the indoor-outdoor gap. In July you are choosing for one temperature. In October you are choosing for a range, and a pullover that is correct for the walk to the studio may be far too warm for the studio itself. Getting the weight right is what lets one piece serve both ends of that gap.
What actually changes between a 300gsm and a 450gsm pullover
A midweight pullover, in the region of 280 to 340 gsm, is a fleece-back jersey or a brushed loopback. It has visible loft, it holds a shape when you take it off, and it insulates adequately as a single layer in a heated room. It is the weight that works in a studio at about twenty degrees and on a walk at about twelve.
A heavyweight pullover, from roughly 400 gsm upward, adds real thermal mass. It works as a single outer layer in a cold room or a cool walk, and it works as a mid layer under a shell. The cost is that it cannot be worn indoors in a heated studio at all without overheating, and it cannot be worn under a fitted jacket without bulking the shoulder visibly.
Loft matters as much as weight, and this is the part most shopping advice gets wrong. Two pullovers of identical gsm can behave completely differently if one is brushed and the other is smooth. A brushed back traps air in the raised fibre ends. A smooth face of the same weight lies flat against you and conducts far more heat away. If a listing gives you weight but not finish, assume smooth, and assume you have under-warmth.
Since most listings publish neither, you have to handle it. The compression test is the fastest honest one: fold the garment in half, press the layers together with the flat of your hand, then release and watch how fast it returns. A brushed fleece-back springs back and stays slightly lofted. A smooth heavy jersey stays compressed and shows the crease far longer. That difference predicts on-body behaviour better than any number.
The second test is the armhole. Reach across and pinch the fabric at the underarm where a sleeve seam would meet the body. If you can gather more than about a centimetre of excess fabric there, it is a relaxed pullover and it will feel bulkier through the torso than the same weight in a fitted cut. Cut and weight are independent variables and people only ever shop one of them.
Finally, look at the collar and cuff ribbing. A rib that matches the body in weight produces a collar that goes slack after a season and a cuff that stops gripping the wrist. A rib heavier than the body is more work up front and it is the difference between a pullover that still looks deliberate in its second autumn and one that reads as tired from the neck down.
The wrong way to buy a pullover for autumn
The wrong way to buy is to pick a weight for the weather forecast and then try to wear it everywhere. That produces the familiar outcome: too hot walking in, too hot during the class, and then it lives on a hook by the door unworn for two months.
The right way is to pick a weight for the place you spend the most time indoors, and then check that it also works as a layer outside it. In a heated studio running twenty-two to twenty-four degrees, a midweight is almost always correct and a heavyweight is usually too warm within ten minutes. Outdoors at eight to ten degrees, that same midweight works as a single layer for a walk of twenty minutes or as a mid layer under a shell for longer.
If you only ever exercise in a room you control, buy heavier. A garage, a basement, an unheated home practice space and a cold studio all justify a heavyweight that you would never wear into a commercial class. This is the one situation where buying for the coldest space is correct rather than a mistake.
The gap you are actually managing is the walk plus the room. A useful habit is to treat the outer layer as the variable and the pullover as the constant. Choose a pullover that is correct for the room, then add or remove an outer layer for the walk. Buying the pullover to handle both forces you to compromise on both.
There is a failure mode specific to layering that is worth naming. A heavyweight pullover under a shell shifts the shoulder line forward and adds visible bulk at the upper arm, which is exactly where a fitted jacket is least forgiving. If your autumn shell is fitted through the shoulder, a midweight is the only weight that works under it. If your shell is relaxed, a heavyweight becomes possible again.
The buying test that catches the wrong weight more than any other: wear it indoors for a full session before you commit. If you are still comfortable at minute forty, the weight is right. If you peeled it off halfway, it was too heavy for that room. This is the only measurement that matters and it costs one session rather than one return.
Why the same weight reads differently in different colours
Weight is perceived partly through colour, and this is not a small effect. A dark garment hides volume because there is less light bouncing back off it to define the edges, so a heavyweight in a dark neutral reads lighter than a midweight in a pale one. If you are trying to look less bulky, the colour is doing at least as much work as the weight.
Light colours do the opposite. A cream or a warm butter pullover shows every fold and every bit of loft because the shadow side of each fold contrasts against the lit side. A midweight in a pale colour can easily read heavier than a heavyweight in black, purely from the light behaviour.
Texture and weight also interact in a way that reverses the usual expectation. A smooth heavyweight in a dark colour is a relatively flat, unobtrusive garment. A midweight with a sherpaed or heavily brushed face in a pale colour has both more volume and more contrast, which is why heavy brushed fabrics are usually offered in darker colours for this reason.
The practical takeaway for autumn is that if a pullover looks bulkier than expected, changing the colour is a cheaper experiment than changing the weight. Buy or choose the darker of two options and reassess, because a lot of what reads as bulk in an autumn garment is the light rather than the fabric.
A pullover weight check you can do in a shop
- Fold it in half, press flat with your palm, release. Brushed fleece-back returns lofted; smooth jersey stays creased.
- Pinch the fabric at the underarm. More than a centimetre of gather means a relaxed cut that will read bulkier than its weight.
- Compare the collar rib to the body fabric. A matching-weight rib goes slack by the second autumn.
- For a heated studio at twenty-two degrees or above, midweight is almost always correct and heavyweight is too warm.
- A heavyweight only works under a shell if that shell is relaxed through the shoulder. Under a fitted shell it bulges visibly.
- Wear it indoors for a full session before you commit. Comfortable at minute forty is the only measurement that counts.
The Short Version
A midweight and a heavyweight pullover are two garments, not one garment in two thicknesses.
Questions people actually ask
What gsm should an autumn pullover be?
Roughly 280 to 340 gsm for a midweight that works in a heated studio and on a walk, and above 400 gsm for a heavyweight you will only wear in a cold room or under a shell. Most listings publish neither figure, so judge by loft and by the palm-compression test instead.
Why does my pullover look bulky when the size is right?
Because bulk comes from fabric weight, finish and seam placement rather than from the fit being wrong. A brushed back traps air and adds volume, and a relaxed armhole with more than a centimetre of gather adds more. Try the same weight in a more fitted cut before you change size.
Can I wear a heavyweight pullover to a heated yoga class?
Usually not. A heavyweight pullover that works as a single outer layer outdoors will usually have you peeling it off within ten minutes in a studio running twenty-two degrees or above. Wear a midweight and put the heavyweight on for the walk there and back.
Does a heavier collar rib matter that much?
More than most people expect. A rib that matches the body in weight goes slack after a season and the collar starts to read as tired from the neck down, which is the first place the eye goes. A rib heavier than the body costs a little more up front and keeps the pullover looking deliberate longer.
FREQUENTLY ASKED QUESTIONS
- What gsm should an autumn pullover be?
- Roughly 280 to 340 gsm for a midweight that works in a heated studio and on a walk, and above 400 gsm for a heavyweight you will only wear in a cold room or under a shell. Most listings publish neither figure, so judge by loft and by the palm-compression test instead.
- Why does my pullover look bulky when the size is right?
- Because bulk comes from fabric weight, finish and seam placement rather than from the fit being wrong. A brushed back traps air and adds volume, and a relaxed armhole with more than a centimetre of gather adds more. Try the same weight in a more fitted cut before you change size.
- Can I wear a heavyweight pullover to a heated yoga class?
- Usually not. A heavyweight pullover that works as a single outer layer outdoors will usually have you peeling it off within ten minutes in a studio running twenty-two degrees or above. Wear a midweight and put the heavyweight on for the walk there and back.
- Does a heavier collar rib matter that much?
- More than most people expect. A rib that matches the body in weight goes slack after a season and the collar starts to read as tired from the neck down, which is the first place the eye goes. A rib heavier than the body costs a little more up front and keeps the pullover looking deliberate longer.
WORTH A LOOK
ABOUT THIS GUIDE
Written by Alo Editorial. Every fit and fabric claim in this guide is checked against the pieces we actually sell — if something does not apply to your size, body or climate, our customer care team will say so. Corrections get published, not quietly deleted.
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