Buxom pin-up Kate Upton is used to setting male pulses racing all around the world.

But well before the sultry and exotic photo shoots began, the Michigan-born 20-year-old was more into spending her free time in hay barns.

Upton started riding horses competitively in her early teens and even then she was a show-stopper — and Celebuzz has the exclusive photos to prove it — complete with bedazzled costume, oversized gold belt buckle and black Stetson.

As a young equestrian, the Sports Illustrated cover girl was involved with the American Paint Horse Association and competed at a national level — and was quite successful.

With the help of her horse, Roanie Pony, she won three APHA Reserve World Championships and as a teen was named the 13 and Under Reserve All-Around Champion.

The second horse she competed with named Zipped won 14-18 Western Riding and was included in the top 5 in 14-18 Horsemanship and 14-18 Western Pleasure in 2009.

In an interview with GQ Magazine the Carl’s Jr. babe professed her passion for horses: “What will I love for the rest of my life? Horses and Jesus seem like safe bets.”

And to mark her lifelong love, she even confessed to having a horseshoe tattoo on her wrist and on the inside of her finger she has an inking of a small cross.

Although she is still just 20-years-old, Upton has already graced the cover of SI twice, the coveted spot that also jump-started the careers of supermodels Christie Brinkley, Rachel Hunter, Heidi Klum, and Tyra Banks.

So, would you rather see Kate in her sparkling horse-riding outfit or a skimpy bikini? Which does she look better in? Give us your opinions below.