katherine schwarzenegger.te chops. on the plaza, an attempt of a guinness world record. fit, this is "today" on rsnb coñ( ♪ >>> we're back. with our break-long series "break it today." we've teamed up with our friends at the guinness world records to celebrate the release of the book. >> this morning, a competitor looking to set one by splitting the competition in half. meet the hammer. ron is a real-life fruit ninja, crushing watermelons with a single punch. he's a vert if ied trainer and boxing expert. he's been fighting his way into the guinness world record books. the longest punching marathon. today, ron is looking to have the most watermelons split with a karate chop. ron is almost ready to go, along with michael empric. what is the current record right now? >> the mark to beat is 40 watermelons. they need to be split in half with a karate chop. not a fist. >> why watermelons? >> the last record i set, was a punch bag marathon. i decided i wanted to have a one-minute record. >> do you feel confident? >>