He came up with a variety of undergarments that were designed to wick away sweat and keep athletes cool and comfortable.
It's perhaps a little surprising then that Under Armour has gotten into the business of keeping people warm.
What's not surprising, given Under Armour's well deserved reputation for quality, is how well the aptly named Under Armour Cold Gear line does what it's supposed to do, which is to keep athletes warm when conditions get cold.
It's a departure from what the company has classically done, but they've been able to make the transition successfully, becoming an integral part of many athletes' winter training.
Athletes who train outdoors in the winter have a unique challenge.
On one hand, keeping warm is absolutely essential.
Losing heat to the cold means reduced performance, discomfort and a much higher risk of injury.
The problem, one which the Under Armour Cold Gear attempts to solve, is how to keep warm without causing sweat to become a problem.
Anyone who has spent time outside jogging or skiing is probably going to be familiar with the issue.
If you've got enough clothes on to keep warm, then you've got enough clothes on that, most likely, you're not going to be able to get the moisture away from your body.
This is one of the reasons that layering, the concept around which Under Armour Cold Gear is built, is so important.
The various layers allow you to keep your body insulated, while still allowing the body to get rid of excess heat through moisture.
This allows your body to maintain the right core temperature, leading you to be more comfortable and fostering better performance at your chosen sport.
With that in mind, the Under Armour Cold Gear line has products intended to be part of three different layers.
Base Layer - The base layer is the layer of clothing that is close your skin and is intended to wick moisture away, keeping your dry.
In the Under Armour Cold Gear line, this is where you'll find turtlenecks, leggings and other fairly tight fitting clothes.
Cold Gear Compression and, not surprisingly, Base lines fall under this category.
Mid Layer - Unlike the base layer, this is designed for actual insulation, and may actually be multiple layers.
Under Armour has the Cold Gear Loose line, which is intended to be used for this purpose and, as the name implies, is looser fitting.
Shell Layer - The top layer of clothing, which is there to protect you from the elements.
This is represented in the Under Armour Outwear line, and it consists of coats, jackets and pullovers.