Playground time for kids can be exercise time for mom

When my kids are at the playground, I'm usually the only parent making a spectacle of herself. I do push-ups and lunges. I hang from the monkey bars and try to pull myself up. Or I repeatedly squat down, lower my butt until it hits the bench and then stand up.

Yes, playground workouts can be embarrassing, especially when other moms and dads are relaxing or chatting on cellphones. But if you're strapped for time, playgrounds are ideal workout spots, and not just because they're free. You're stuck there anyway, they've got all the equipment you need, and research shows even tiny bouts of exercise are associated with increased fitness.

And while a public workout takes some courage, "your actions might inspire a lifetime of health and fitness in your children or others," said celebrity fitness trainer Marco Borges.

For some people, playground equipment may even be better than regular-size workout structures, said Borges. Monkey bars, for example, are built for kids so they're shorter than regular pull-up bars. "That means you can start from a standing position and use your legs for added help," said Borges.

Though your own body weight is really all you need for a good workout, almost all playgrounds offer at least three key pieces of equipment that can enhance the experience: monkey bars, benches or stairs, and swings. Here's how to make use of each one:

Monkey Bars: Chin-ups

Hang with your hands slightly wider than shoulder width apart with your palms facing toward your body. Pull your body up until your head is above the bar, then slowly lower to the starting position, said exercise physiologist Tom Holland, author of "Beat the Gym."

What it works: An upper-body-resistance workout, chin-ups target several major muscle groups in the back, shoulders and arms. They also work core muscles.

Kick it up a notch: Try a pull-up by changing your hand position and grabbing the bar with your palms facing away from you. Or add a weighted backpack.

Make it easier: Rest your feet on the ground if the bar is low enough. Or simply hold your chin over the bar as long as you can, a strength test called the "flexed arm hang." Simply hanging from a bar stretches and relaxes the back. Or hang from the bar and tuck your knees up to your chest.

Bench, Stairs or Low Platform: Bench step-up

Place your right foot on a bench about knee height. Step up and tap your left foot on the bench while fully extending your right leg. Slowly step back down with the left leg, then immediately repeat, said Holland.

What it works: The legs (hamstrings and glutes) and core muscles.

Kick it up a notch: Find a higher step. Or, place your hands behind your head and jump with both feet on to the bench or platform. Hop back off the step, landing on both feet.

Make it easier: Find a lower step.

Swing set: Ab walkout

Hold the swing with your hands and keep your feet on one spot, said Borges. Using your abs, stretch your body into an elongated position. Return to the start position.

What it works: Abdominal muscles

Kick it up a notch: Balance on one leg.

Make it easier: Do this move on your knees. Or, if you fit, swing yourself. Swinging works the legs, quads, core and improves balance, range of motion and coordination.

Others to try

Bring a jump rope: Skipping rope is a big-time calorie burner — comparable to running — and it's an effective way to build bone density, said Tim Haft, the founder of Punk Rope, a jump-rope-themed workout class. "It enhances coordination, improves timing, rhythm and balance and you don't need to move from one spot so you can monitor your kids.

Find a line or object: Hop back and forth over it with both feet. To make it harder: Hop on one foot.

Play follow the leader: If you can fit, simply follow your child through the play structures. "This can open up a lot of possibilities for agility, core strength, climbing and running," said John Colver, the author of the book "Fit by Nature" a 12-week outdoor fitness program.

Be sly: If you don't want to draw too much attention to yourself, try standing on one leg as long as possible. Or try the Invisible Chair (wall squat) by standing with your back against a tree, wall or piece of equipment. Move your feet away from the wall but keep your hips and back on the wall. Bending at the knees, lower your body until your thighs are parallel to the ground. Your knees should be directly above your feet and be bent at 90 degrees, said military fitness expert Mark Lauren, author of "You Are Your Own Gym.