By Therese Iknoian

A puddle of sweat forms on the floor around Martha in her aerobics class. She breathes hard, stepping faster and faster to keep up. "I'm really getting fit and healthy now!" she thinks.

Across town, John gardened a little this morning. Now, he's walking a mile or so with his dog. "I feel great," he thinks. "This exercise stuff really does make you healthy!"

Your call: Who's getting healthier?

Martha, of course, you think. She's working harder.

Think again. Recent studies seem to indicate that John might be getting just as healthy as Martha is. All right, so there are those researchers who claim that gardening just ain't enough for fitness. But steam is gathering -- backed by good science -- that if you do enough of the small stuff, you'll still get where you want to go (assuming your goal isn't Olympic competition). That doesn't mean doing more or doing it harder isn't good. Keep going if that tickles your fancy; Jack LaLanne would be proud.

But while the researchers pick nits about how much is enough, let's take a look at your options -- and some of the arguments for and against them:

1. The Old School - You probably know the drill: You gotta sweat. At least 3-5 times a week. Hard. And each time it better be 30 minutes or so. OK, already, you can get outstanding results if you abide by this recipe of structured exercise, measuring your pulse so it's between 65-85 percent of your maximum heart rate. Some people will even prefer getting a vigorous dose of exercise a few times a week and being done with it.

Disadvantages: An hour or more each time (with preparation time). Inconvenience since you'll have to go somewhere to do your thing. Special workout clothes and gear. And hard workouts.

Advantages: Higher cardiovascular fitness. Participation in or training for a recreational sport or fun competition. Greater calorie use (read: greater weight loss). And hard workouts.

2. Quick Hit Fitness - We're having fun now. Turns out you don't have to do those 30 minutes all at once if you don't want to. Studies have shown that 10 minutes, three times a day -- do them briskly, as if you had a bus to catch -- will pack just as much punch to the health of your heart and lungs.

Disadvantages: Discipline to remember to get moving three times each day. Comfortable shoes a must. Keep it brisk.

Advantages: Moderate fitness. Do it anywhere, anytime. No need to change clothes. Fits into your life without fuss.

3. Every Little Bit Counts - This seems too easy, but it's true. Researchers from the Centers for Disease Control and the American College of Sports Medicine say we can accumulate 30 minutes of moderate activity on most days to get healthier. That means taking the stairs, gardening, chasing after the kids, walking the dog after dinner, whatever ties your laces ... and totals 30 minutes. Make everything you do everyday more active. And try to make them brisk, too.

Disadvantages: Less weight loss or fitness gains. Less muscle tone.

Advantages: Anytime, anywhere. No need to pack workout bags or think too hard. Just move. Increased health.

Exercise choices. That's the best part. We can do what we prefer, be it Martha's sweat or John's garden-putzing.

Just move.