The game had been over for more than an hour, and the playing field at Tropicana Field in St. Petersburg, Fla., was dimly lit on that May night in 1998, which is why no one noticed the figure standing outside the visiting dugout until the peace was shattered by a loud “Aauuugggh,’’ followed shortly by the sound of a medicine ball slamming to the turf.

It happened again and again and again.

“Aauuugggh.’’

Slam.

“Aauuugggh.’’

Slam.

Why, it was Cal Ripken Jr., baseball’s iron man, getting in a little core workout before calling it a night.

The Baltimore third baseman held the weighted ball at his waist and flung it over his head. Then, with his hands holding the ball at chest level, he pushed it nearly straight in the air.

A medicine ball?

Believe it.

One of the oldest pieces of training equipment is also one of the most versatile.

And it is inexpensive and relatively easy to use, meaning you don’t have to be a Hall of Fame baseball player or a scholarship athlete to have access to a medicine ball.

And you don’t need a private trainer or even a workout partner to realize its full benefits.

You just need a medicine ball, enough room to lie down and twist your body, a sturdy wall (optional), an open area where you can throw the ball (optional) and the willpower associated with wanting to get into or maintain your shape (mandatory).

It worked for those under the care of Hippocrates back in 300 B.C., who tossed animal skins filled with sand to prevent or recover from injuries, and it can work for you today.

“It’s one of the most, I don’t want to say primitive, but basic forms of training,’’ said athletic trainer Mike Gough, who owns Athletic Edge Sports Performance Conditioning in Lakewood Ranch. “You don’t need a lot to get a good workout at home. A simple tool like that you can do so many things with, it’s amazing.’’

Medicine balls range from two pounds to 25 pounds. Prices range from $15 to $60.

Some come with handles. Some come with ropes and can be swung.

They are designed to increase your core strength (abdominals, lower back, spine and hips), build strength in both the upper and lower body and improve flexibility.

Workout tips

The uses for the medicine ball seem almost limitless.

To tighten your abs:

• Lie on top of a bench and hold the ball on the sides above your chest. Press the ball toward the ceiling while keeping your body still. Slowly lower the ball. Repeat.

• Lie on top of a bench and hold the ball on the sides above your chest. Move the ball over your head using your shoulders. Slowly return the ball. Repeat.

• Lie on the floor with your legs bent and your feet and head touching the floor. Hold the ball over your chest. Bend your arms and curl toward your legs while tightening your stomach muscles.

• With your knees bent lie with back and feet on the floor. Squeeze ball with knees. Hold arms at your side with your palms down. Lift your butt off the floor and bring ball over your chest. Slowly place feet on the floor. Repeat.