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American football’s Super Bowl Sunday is the biggest annual event in US sport, and one of the biggest in the world.

Some of the Super Bowl’s typical numbers are mind-blowing: a domestic TV audience of 114m people; 25m tweets posted during a game; companies paying US$4.5m for a 30-second slot during one of the game’s advert breaks; and fans watching on TV spending an average of $78 each just on snacks to eat during the game.

But it’s not a sporting institution in rude health. Some observers believe that American football is dying a slow and painful death.

Several reasons for this have been identified, although one in particular is posing a distinctive set of challenges for the sport: the rise of the millennial generation, a group which in the US now outnumbers baby-boomers by 10%.

Born between 1980 and the mid-2000s, millennials have become the most influential consumer generation in history, according to some commentators.

A US government report has characterized the group as being highly diverse, unattached to organized politics and religion, linked by social media, burdened by debt, distrustful of people, in no rush to marry and optimistic about the future.

As consumers, the behavior of millennials manifests itself in numerous ways: for example, by how they priorities access to resources over ownership of them.

They also live life online, through the worlds of Instagram, Snapchat and Twitter. Recent research suggests on average millennials spend more than 11 hours per week watching clips on YouTube that last no longer than two or three minutes.

The Super Bowl be warned: Sunday’s NFL extravaganza lasts four hours (three and a half hours of the game and 30 minutes of half-time entertainment).

The threat to American football is no illusion. In a recent study, four out of five millennials stated that they were less trusting of the NFL than basketball, baseball, hockey or NASCAR. Out of those surveyed in the study, 61% identified the NFL as a “sleazy” Organisation, while 54% saw it as being anti-gay.

In another study, teenage interest in the NFL was found to have fallen from 26% to 19% over the last two decades. The study also identified that in Canada, this figure is even starker with only 14% of teenagers following the Canadian Football League.