Every week, a new STACK Challenge gives you an opportunity to test your athletic ability and win a STACK T-shirt. Take the challenge and enter to win by tweeting your results with #STACKChallenge.

Bored with your conditioning workout? Mix things up one day this week with the brutal Mount Everest Treadmill Challenge from trainer Lacey Stone. The whole challenge lasts less than 20 minutes, but it’ll probably be the toughest thing you do this week.

To perform the Mount Everest Treadmill Challenge:

• Warm up for three minutes at a comfortable pace
• Increase the speed to 70 percent of your max (should be around 6-8 m.p.h.) and run at a two incline for three minutes
• Increase the incline by two increments while maintaining your speed. Run for three more minutes before repeating the pattern again
• Keep going until you reach a 12 percent incline
• Be sure to hold the rails when getting on and off the treadmill

The Challenge

Run at a steady pace while increasing the treadmill incline by two percent every three minutes until you reach a 12 percent incline.

How Do You STACK Up?

Rookie: 6-8 percent incline
Pro: 10 percent incline
All-Star: 12+ percent incline

How to Win a STACK T-Shirt

1. Complete the challenge by Sept. 21
2. Follow STACK on Twitter (@stackmedia)
3. Tweet your results with #STACKChallenge

Watch next week’s STACK Challenge to see if you won.

Get Better

Build explosive power for your sport with a variation of this challenge: Todd Durkin’s Terrible Treadmill 10. Also, check out more treadmill challenges from Lacey Stone.