For an added burn, try exercising on the sand

Most people associate the beach with swimming or surfing, but the water isn't the only exercise-friendly element. Many developed beach areas, such as Santa Monica and Venice, also feature bars, rings, swings and balance beams -- free equipment that can make a workout engaging and fun. Plus, the sand offers a shifting surface that forces the stabilizing muscles of the core to fire. Feet sink in, making muscles work harder and creating a bigger calorie burn.

Jennifer Cohen ( www.jennifercohen.com), fitness trainer and author of "No Gym Required," chose the Santa Monica Beach near the pier for a workout. As cyclists wheeled along the bike path and a few souls braved the water, she showed a number of strength and aerobic training exercises that can be done on a warm day -- make that most days in L.A. -- or even a brisk winter one. Pails act as weights when filled with wet or dry sand, adding an extra challenge. These exercises are also easily done at a park or a playground with similar equipment.

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Ab crunches and pelvic tilt on a swing

Lie on the sand on your back with your feet in a swing seat, legs extended and hands behind your head. Contract the abdominal muscles, bringing the knees and the shoulders together without straining the neck. Release and repeat. This targets core muscles. For the pelvic tilt, place back and head on the sand, and feet on the swing seat with knees straight. Push the pelvis up and release, squeezing the glutes.

How many: Repeat both exercises about 15 times.

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Decline push-ups on a balance beam

Push-ups on a decline (where hands are lower than feet) have an added degree of difficulty, since the body is working harder against gravity. Place hands in the sand and toes on top of a low balance beam (or, to make it a little easier, place them against the side of the beam) and, with hands shoulder-width apart, lower the chest to the ground as far as possible while keeping the body straight. This works the entire upper body and engages the core, which has to work even harder to stay stable since hands are on an uneven surface and digging into the sand.

To add even more difficulty, bring one knee toward the chest during the push-up, alternating legs. You can also switch between bent-leg and straight-leg push-ups. Not that much upper body strength? Switch things around and do an incline push-up, with hands on the beam, toes in the sand.

How many: Three sets of 10 to 12 reps.