It's summer, so that means it's safe to go outdoors and play -- and burn calories in the process.

The days of feeling trapped within the walls of your home or gym are over (for now).

Whether it's gardening, in-line skating or a leisurely game of golf, there's plenty of summer activities to help you get in shape and stay there.

Summer shape-up

When the Walsh family moved from Minnesota to sunny California in the debut episode of "Beverly Hills 90210," Brenda learned her days of hiding those extra pounds she gained under bulky sweaters were no more.

Unfortunately (or fortunately -- depending on who you ask) we live in a region that requires the annual "store the sweaters away" chore.

Whether you were an avid gym rat in the winter but can't wait to get outdoors or your only workout consisted of shoveling snow, summer offers a chance to burn calories with a varietal of enjoyable outdoor activities and exercises.

If you don't have a dog or a garden, but you have a little one, you can do what Ann Edens, personal trainer and lead exercise instructor for Fitness Pointe in Munster does -- "behind-the-stroller-jogging."

Other summer activities enjoyed by Fitness staff members include water aerobics, walking, rollerblading, baseball and tennis. Fitness Pointe Facility Supervisor Nikki Sarkisian is particularly fond of on-water rowing.

"It's a total body workout," she said.

Sarkisian and Edens recommend summer exercisers check out www.calorieking.com to track how many calories are burned depending on the activity and the duration of time spent doing it. Users can punch in their gender, age, height and weight and obtain accurate information for calories burned doing activities like snorkeling, canoeing, hiking and horseback riding.

Chad Leader and his wife Kim's preferred summer "stay-in-shape" activity is trail running at hiking areas such as the Indiana Dunes National Park. Leader, a personal trainer at Fitness 1 in Winfield and proprietor of Ultimate Test Lab, believes that staying in shape for summer must entail some type of progression.

"There are so many ways to progress in hiking," he said.

Leader recommends beginners start on easier trails and as they get in shape tackle some of the tougher ones with elevation.

"By the end of summer, you want to be doing something you couldn't do at the beginning," he said.

Ken Richmond of Valparaiso doesn't count calories, but he makes sure to stay in shape over summer by playing softball in an adult men's league.

"It entails a lot of running," Richmond said. "It keeps your legs in shape. With softball you use all of your muscle groups. It's good cardiovascular."

Better Homes and Garden (www.bhg.com) offers a few summer tips to stay in shape:

Walking the Dog

A casual stroll with Fido burns 3.5 calories per minute. Want to burn more calories? Play a game of chase.

Gardening

Burn 4.5 calories a minute by pulling weeds or planting summer flowers.

Volleyball

Burn 5 calories a minute on a court, but twice as many when you play on a beach.

Rollerblading

Burn around eight calories per minute by skating on a flat surface; blade uphill to burn 11.