Transcript for The Science Behind Tennis Players' Grunts
Can sign up the next and the US open is under way right now and you know it's a very classy events. It's -- for one very audible destruction from the players on the court case in point. Yeah. And some -- -- I mean you're talking about Maria Sharapova yeah 9:3 -- with the central. Strength as a motorcycle. Jack camera -- up until it was a good thing really yeah. A slight advantage in the -- the reason -- -- -- -- that much care your contract here abdominal muscles. -- tighten up your four and it actually allowed to. Form -- the power exertion 4% in back of an increase in the balls velocity. Went a little thing behind -- -- -- -- -- -- -- -- -- How viable but hey you know you've worked so let's let me educate you your lunch in intimate moment to reflect. It's indicated that the law -- should have -- better. This -- the -- doesn't exactly. They're not bad anyway apparently there's more force when -- -- grunts. That helped take back -- Now -- pretty incredible video I've heard and leaves the scene to neverland -- but you have to take a look at some of the go -- camera now find that it is unbelievable footage. You know it's. We'll figure out what -- that -- -- -- those. Atlanta home he would collect from the points while the other wing suits and towels and the closing of the dream without letting you I want -- -- there's only a few feet away from getting. Home -- something. But -- -- we'll go slow approach to go things that don't -- -- foot and. Because ear toward speeches from looking at this you got me it really is amazing how you can. I'm over you and just yeah not to -- sometimes but yet had -- -- they're probably equipment companies have. This next story is incredibly heartwarming. -- -- from Copenhagen just completed the Iron Man Peter my brother and his twin Brothers being involved 34 years old Peter. Has several palsy and he has now become the first person with the disorder to complete an Iron Man triathlon. He took the -- fifteen hours 32 minutes 482 place went to a half mile cycling a 112 miles running 26 miles. They did it all together. It is definitely one of those inspiring things saying don't ever let anything stop him from achieving your true. And look what we go to break we have to leave you with this image the -- -- ever looking in the -- and what did you see 8000. Its yeah. Do you see you -- an adult and didn't get didn't drop me -- ABC news anchor the perhaps.
This transcript has been automatically generated and may not be 100% accurate.