Side effects may include shortness of breath and extreme fatigue.
Running 400m doesn't sound like much of a challenge, does it? But what if you were to run those 400m at an altitude close to 200m and as a pure uphill sprint? That's a race guaranteed to put your calves, quads and endurance to the ultimate test.
Red Bull 400 is set to conquer the ski jumps of Europe and North America this year, putting sprinters all over the world to one of the toughest tests they will ever face.
Warm up your leg muscles and sign up for the hardest 400m of your life.