WHEN THE gym walls start closing in, take advantage of one of Southern California's best features -- the beach.
On a recent weekend in Santa Monica, we found men and women doing acrobatics, practicing yoga, playing in-line hockey, and walking the slack line. A few adventurous souls even made the most of playground equipment -- rings, high bars, parallel bars and ropes.
For those intrigued by the possibility of exercise in the ocean breeze and sunshine, solitude is only an iPod away, but so are people more than willing to demonstrate a martial arts move or deconstruct a back flip.
We offer the lowdown on the appeal of beach workouts, what muscle groups each activity targets, and whether it qualifies as a good cardiovascular workout. (Calories are approximate and based on a 150-pound person exercising for an hour.)
Don't look for comments from cyclists and runners -- they couldn't stop for questions. And the stroller-exercise moms? Talking would have risked waking Junior.
Name: Ahmad Saleh, 32
Benefits: A push-up like this shifts the center of gravity and ratchets up the difficulty level. Muscles used include the triceps, pectorals and deltoids. Calories burned per hour (based on vigorous calisthenics): 550
Why the beach? "There is no seniority here. Everybody learns from each other. I have a great day, working out for about seven to eight hours. When you do these things, your brain is so clear and you're happy."
Our expert: Information on this and the other exercises was provided by Steven Hawkins, associate professor of exercise science at California Lutheran University in Thousand Oaks.
Names: Roger Ades, 50; Anthony Rogers, 48
Benefits: Uses all lower body muscles, plus some core and upper body muscles. Jumping works fast-twitch muscle fibers and builds bone strength. Limited cardio gains because of the game's stop-and-start nature. Calories per hour: 550
Why the beach? Ades: "I still lift once a week, and I play indoor volleyball. I get a workout in the gym, but I've done it for so long and the routine is just so boring."
Brisk walking (including stairs)
Name: Molly Pitz, 30
Benefits: Any time stairs are added to a walking routine, leg muscles get an extra boost. It produces greater cardio benefits as well, since the heart works harder. Calories burned: 300
Why the beach? "There's so much down here to do. I have a gym in my building, and my trainer has a gym, but we prefer it down here. Especially on Saturdays -- it's very entertaining."
Names: Neal Cordova, 20; Ben Suvonnasupa, 20
Benefits: Increased muscle strength and power in lower body muscles. Development of fast-twitch muscle fibers. Good for balance training. Calories burned (based on gymnastics): 280
Why the beach? Cordova: "This is the place where anybody who's active can come and find something to entertain themselves, and where everybody can feed off each other's energy."
Name: Clarence Mitchell, 26
Benefits: This Brazilian blend of martial arts and dance targets the upper and lower body, plus core muscles. Also promotes flexibility. Good cardio benefits from continuous, rhythmic movement. Calories burned (vigorous activity, based on martial arts movements): 600
Why the beach? "You can have the privacy of doing your own thing, but there's also a community of people working out. That's nice, as opposed to a gym."
Name: Cay Enns, 38
Benefits: Strengthens and tones abdominal and core muscles, including the rectus abdominis, transversus abdominis, external and internal obliques and erector spinae. Calories burned (based on mild calisthenics): 250
Why the beach? "It's nice to be out and about and you see a lot of regulars here. It's a different experience. You want to work out. If you go on a run, there's so much to see. It keeps your mind off the fact that you're exercising."
Names: Kelly Perkins, 16; Kent Smith, 55; Daniel Reitzenstein, 25
Benefits: Skating -- forward, backward, sideways -- targets all major lower-body muscles. Great cardio gains from continuous movement, and intermittent bursts of activity provide interval training. Best results come from playing with similarly skilled competitors. Calories per hour: 550
Why the beach? Smith: "You can't beat it. You've got the fresh air and the ocean."
Name: Ali Moradi, 33
Benefits: Running forward stimulates the quadriceps and the calf muscles; running backward targets the hamstrings and glutes. Running continuously for several minutes at a time, then taking a break, then running again, provides substantial cardio interval training. Calories burned: 500
Why the beach? "When you go to the gym, it kind of gives you a fake puff. But the strength you gain from this never really goes away; it always stays on you. It's true strength."
Names: Eddie Avila
Benefits: Substantial upper body workout, targeting arms, shoulders, chest, back and possibly the core. Swinging for at least five minutes at a time would give a mild cardio boost. Calories burned (based on gymnastics): 280
Why the beach? "I probably get a better workout at the weight room, but this isn't bad. But do I do it for that? I don't think so. I do it to feel better up here [points to his head]."
Name: Ernie Thrash, 42
Benefits: Walking a thin, flat nylon rope between two points improves balance, which is part of functional fitness, or training the body for real-life situations. The core and leg muscles react to the line as it moves.
Why the beach? "There's stuff to play on and you can hang with really good people. It's a place where you can come and learn something for free. A person can walk up and say, 'I'd like to learn that.' 'OK, come on.' "