Top athletes are generally taller today than in the past. Olympic star Usain Bolt is 6 feet 5 inches tall and 207 pounds. Jessie Owens, 1936 Olympic gold medalist, was nearly 5 feet 11 inches, and 165 pounds.

(AP Photos)

With the Denver Broncos preseason in full swing, there's fierce competition for the role of starting quarterback.  The potential winners include Mark Sanchez, Trevor Seimian and Paxton Lynch. According to research, Lynch has at least one advantage: At 6 feet 6 inches, he's the tallest of the three.

Height and weight equal speed in sports, according to mechanical engineering professor Adrian Bejan and his colleagues at Duke University, who've studied the growing stature of top athletes. Bejan says you don't have to look further than Olympic athletes like Usain Bolt for proof that taller and bigger are better. He describes what he calls his "theory of sports evolution" in his book "The Physics of Life." Bejan spoke with Colorado Matters host Nathan Heffel.