Running shorts come with a number attached — the inseam, in inches — and an unspoken social code nobody explains. Here's what the numbers mean, what they're actually for, and how to pick without buying three wrong pairs first (the traditional method).
What the inseam number means
The inseam is the seam from crotch to hem. A 5-inch short ends mid-thigh; a 7-inch short sits an inch or two above the knee. Threes exist for racers and extroverts. Nines exist for basketball. Between five and seven is where most ordinary running happens.
The case for 5-inch shorts
- Freedom. Nothing near the knee, full stride, maximum airflow. On hot days this matters more than any fabric technology.
- Less fabric, less bounce. Lighter, less material to hold sweat, nothing flapping at pace.
- The runner look. Fives read as "person who runs on purpose." Whether that's a pro or a con is between you and your mirror.
The catch: shorter shorts mean more skin contact, so if your thighs touch — most humans — you'll want a liner that covers the contact zone or a pre-run visit from the balm ritual.
The case for 7-inch shorts
- Built-in chafe protection. The fabric physically covers where thighs meet. Mechanical prevention beats chemical prevention.
- Versatility. Sevens run, gym, travel, and do the school pickup without announcing your hobby.
- Modesty margins. Sitting, stretching, and post-run café stops all get easier.
The catch: marginally warmer in summer, marginally more fabric when soaked by British rain (see the temperature guide — rain features heavily).
The honest decision tree
- Do your thighs touch? Yes → 7-inch, or 5-inch with a proper liner. This one factor outranks all others.
- Mostly hot-weather running? → 5-inch earns its keep.
- One pair for everything? → 7-inch, no contest.
- Racing ambitions and no shame? → threes are down the corridor, good luck.
Liner or no liner?
Most running shorts include a built-in liner — a brief or boxer layer that provides support and takes over the friction duties. Lined shorts mean no underwear decisions (running in cotton boxers is a one-time experiment). Unlined shorts suit runners with strong opinions about their own base layers. For everyone else, the liner is doing quiet, heroic work.
Fit notes people learn too late
- The waistband matters more than the length. A drawcord you can actually adjust beats any inseam decision.
- Pockets you can trust — zipped, or deep side-drop — turn shorts from sportswear into transport.
- Check the size guide, not your assumptions: shorts sizing varies between brands more than t-shirts do.
Why ours are seven inches
We picked one length and committed, because most people do not want a decision tree, they want shorts that work. Seven inches keeps thigh off thigh for the majority of runners, which removes the single most common cause of a ruined long run. It also stops well short of looking like you are wearing trousers.
That is the 7 inch Suffer Shorts, and they pair with The Blister Socks and the Agony Tee in The Kit.
Common questions
What length running shorts should I buy?
Five inches if your thighs do not touch and you want maximum freedom, seven if they do or you want more coverage. Nine and above is comfort-first and slightly warmer. Most runners are happiest at seven.
Do longer running shorts stop chafing?
They help a lot, because they physically prevent skin-on-skin contact. They do not solve chafing caused by seams, waistbands or wet fabric, so length is one part of the answer rather than all of it.
Should running shorts have a liner?
If you like the support and do not want to think about underwear, yes. If you prefer your own base layer or find liners hot, no. Neither choice is wrong and anyone insisting otherwise is overthinking shorts.
Are split shorts worth it?
For racing and fast sessions, they are excellent. For everyday running they offer very little that a normal short does not, and rather more exposure than most people want on a Tuesday.
How should running shorts fit at the waist?
Snug enough that they do not shift when you run, loose enough that the waistband is not pressing a line into you. If you are constantly hitching them up, they are too big, not too short.
Related reading: how to stop chafing, the minimal kit list, what to wear at every temperature.
Our answer, since you asked
The shorts in The Full Kit were built for ordinary distance: enough length to keep thighs on speaking terms, light enough to forget, with a liner that does its job silently. We are, admittedly, biased. But we're biased from experience.
Whatever the length: suffer every mile. THE ORDINARY TIMES, sizing desk.