This could be great news for HTC, as well. It's a company that's been struggling financially, even as it triumphs with tech fans and journalists. The Taiwanese smartphone king has a reputation for quality design, and if it can be the company that finally cracks the wearable market with something functional and beautiful, it could find itself back on the inside track from cult favourite to mega brand – a bit like UA in Europe, in fact.
Even if their partnership starts with nothing more than a native app on the upcoming HTC One M9, that could be extremely useful to them. Apple and Nike shared a mutually beneficial partnership when the iPhone launched. So too could Under Armour and HTC.
There's another reason that Under Armour has been getting its cheque book out in order to grow: UA Record has struggled to make an impression since launch, with users complaining of glitchy software and poor connectivity. It's like an ambitious football team buying a clutch of star players to take it from mid-table respectability to cup success. UA now owns the expertise of Endomondo and MyFitnessPal, and can draw on HTC's hardware assistance. Hopefully it will use those assets to build something user-friendly with deep functionality and wide-ranging compatibility.
The worst thing it could do would be to force users of its new acquisitions on to UA Record, but I am sure they won't make that particular schoolboy error.
If anyone in the UK and Europe underestimated Under Armour before, I doubt they do now. This is a massive company with huge global aspirations, but one that takes the time to understand the markets it wants to move into. All its power grabs so far have been shrewd, and the consolidation of a number of superb fitness entities is great news for tech-assisted runners, as far as I'm concerned.
The next stop is Mobile World Congress, where HTC should be dropping more hints about what it's going to do with UA. As far as the European sport and fitness market goes, this is a little like a third soft drinks brand using new technologies and shrewd, social-based marketing to go up against Coke and Pepsi. This race is on, and I'm hyped about it.