At the West Side YMCA in Manhattan, students are learning martial arts as a self-defense technique, as well as for fitness and personal growth. NY1's Roger Clark filed the following report.

Senior Karate Master Mel Ramsey really is a nice guy, but he is a sixth-degree black belt who can ward off an attacker - in this case, me. 

"It does take some measures not only to learn the technique, but also have the proper attitude when you are walking out on the street," he said.

Ramsey has been teaching karate for 30 years, 20 of them at the West Side, just some of the karate classes the Y offers citywide.

He says when it comes to self-defense, one of the most important tips is to just be aware of your surroundings. 

"We have all of these electronic devices that keep us occupied, and we are not paying attention. And that's when sometimes, things do have a way of happening," Ramsey said.

Many of the students in this class are already advanced, with black belts. They showed me some moves that could come in handy in a confrontation. But a key teaching in karate is to avoid the need to use it in the first place. 

"To feel a certain amount of physical strength, mobility, but also most importantly, to scream really loud and run away," said Kristen Slesar, a third-degree black belt.

"How you carry yourself, how you look around, how you walk down the street says a lot to whether or not someone is going to bother you or not," says June Chin-Ramsey, a fourth-degree black belt.

Learning to defend yourself takes a lot of practice. And you never know when your opponent may wind up being a little bit bigger than you.

If it looks tough, don't worry. Everyone is willing to lend a hand, even playing the bad guy to help you learn. 

"Everybody is very open, very helpful and willing to fall down on the floor if you have to do that to them," said Renauld White, a second-degree black belt.

To learn more, check out ymcanyc.org.