They came in the mail last week. I unzipped the packaging sleeve and felt the familiar luxury of luon against my fingers. But the look was… a bit different from my usual earth tones. Bold. Loud. Unique. My Seawheeze shorts had arrived.

This year, 10,016 runners will lace up their kicks for the Seawheeze Half Marathon, the extra sixteen as a nod to Lululemon’s 16 years of existence. Most will be sweating out their 21.1km in commemorative Lululemon shorts built specially for the occasion and delivered as part of the training package. They’re certainly distinctive—bold and bright in both the men’s and women’s designs. You won’t mistake them for a generic running kit. Loud-patterned shorts aren’t just a clever way for Lululemon to build a product component into the Seawheeze entry fee (ok, 10,016 pairs of shorts won’t hurt the summer numbers either). The true purpose of the shorts is to build community, to create a tangible symbol that brings people together around shared participation in a common goal and love of #thesweatlife. Here’s how they do it:

Unbox community online

It’s the last week of May, almost three months before the event kicks off. We’re in the #prewheeze stage, when runners grind out training laps in prep for chasing their personal best race times. But the pre-race period is for more than just training. This is when Lululemon pulls “Seawheezers” together as a community before they congregate in real life. Browse the #seawheeze or #seawheeze2015 hashtag streams on Instagram and you’ll find more than 30,000(!) unique media. You’ll find more on Twitter and Facebook. Why? The unboxing moment. These funky shorts BEG to be posted. Plus, you get to humblebrag to all your friends that you’re running a half marathon this summer, and you’re going to look damn good doing it. This subtle cue to post using the #seawheeze hashtag is the start of bringing the event community together online. Users can browse the hashtag stream and find others who are running the same race. A quick scan shows posts from users across North America, all decked out in the same unmistakeable gear, all working toward the same goal. It’s a strong and engaged group, and becomes more so as training begins and connections are made. Runners across the globe, united by a hashtag.

Hit the pavement together

We get it: looking at all that media can get community managers very excited.

Connections made in real life are the strongest, and often are key drivers of advocacy and loyalty for the duration of the customer lifetime. This is a big reason why Hootsuite hosts hundreds of Hootups around the world each year. Facetime matters.

Think of the Seawheeze as one big sweaty Lululemon customer meetup. Each year it brings together some of the retailer’s strongest advocates to mingle with customers and connect around yoga, running, and partying. The amount of #brandlove (and sales) generated during the race is staggering. It’s an epic advocate event disguised as a marathon, which comes together smoothly in large part because the community built online expects to meet in real life. That’s kind of the point of running a marathon—you have to hit the pavement with the group on race day.

That community is global, distributed across Lululemon’s markets. However, the race is local, happening in a central location (Vancouver) at a predetermined time. This is a massive advantage for Seawheeze and other similar event communities—natural anchoring allows a very smooth flow from building pre-event digital connections to real life hugs and high-fives. The shorts even take it the extra step, infusing the Vancouver street map into the patterning as a subtle nod to creating a sense of “place” for runners. They’ll connect on those same streets in just a few short (and sweaty) weeks, and be united by the luon webbing they wear. The meetup that began with unboxing continues on concrete.

Keep community (skin)tight

The right fit is super important, with yoga pants and with communities. We all want to feel special, like we’re part of a select group or tribe. This feeling of exclusivity is a powerful hook for community builders to leverage, helping people feel special and high status. Those on the inside are likely to spread the word, feeling like they’re providing unique value to their friends.

10,016 seems like a LOT of people to be a part of an exclusive community. But compared to demand for race spots, it’s barely scratching the surface. This year’s available entry places sold out within half an hour—based largely on word-of-mouth that last year’s race sold out quickly.

This scarcity and exclusivity drives stronger desire to belong to the community, which creates even more urgency and scarcity in turn. It’s a self-fulfilling cycle that empowers sustainable community interest and growth. The challenge for Lululemon is to allow the right amount of additions each year to continue growing at a reasonable rate, without compromising the urgency of fast-driving registration. Smart community builders know that you can’t create a tight community without keeping people out. In fact, it’s essential.

Stitch people together

Remember this: your goal is to build a web of connections, not a bridge to a brand. The strongest communities connect not just to the group’s leader (brand, person, or organization) but to each other. Network theory tells us that the number of connections that a community shares is indicative of strength —when we create a web of connectivity with others around shared interest, we’re much stronger than when we create a single two-way link.

On the most basic level, my Seawheeze shorts are a recognizable symbol to everyone else who has them that we belong to the same tribe. We’re connected to the Lululemon brand, but we’re also connected to each other. And thanks to our new shorts, we can clearly identify others sweating for the same reasons we are.

Laced up in training kicks and sporting my new shorts, I opted for a training run along Vancouver’s iconic seawall last night. A few kms into my route I came upon another runner coming the reverse direction, wearing the same unmistakeable shorts. As we saw each other, we knew we were part of something, the same community working to the same goal. We gave each other the nod, and kept on running. Just now, a little faster.