Downside of Working Out: Injuries : Those who exercise frequently are more likely to be hurt than couch potatoes. They’re also more likely to seek medical help as soon as they need it.

I thought it was only a small step. But it turned out to be more of a giant leap. And when my foot hit the ground as I hopped off the bus that night, I felt something go “pop” in my ankle. I took a step, and felt something else: pain.

“You OK?” asked one of my traveling companions.

“What? Oh, it’s nothing. I’ll be all right in a minute,” I said as I limped along. “I think I just need to walk on it a little more and let it work itself out.”

With every awkward step, I told myself the same thing: “It’s nothing.” I was tough. I was in good shape. I worked out faithfully, three times a week or more. I was not about to be done in by a mere municipal trolley.

Besides, I was scared of what might happen if I did admit that something serious was wrong. I wasn’t quite as far away from home as Neil Armstrong was when he took his famous step. But Athens, Greece, wasn’t exactly my own back yard, either.

We’d been planning to hit the local discos later that night. Luckily for me and my throbbing ankle, it was the off-season, and they weren’t open on Wednesdays. Otherwise, my continued denial could have been embarrassing. (“What do you mean? I always dance this way.”)

The next day, still in pain--and still in denial--I hobbled out to buy a pair of sturdy lace-up boots to make walking less painful, or as I preferred to think of it, more comfortable. Then I proceeded to walk around Europe for a week on what turned out to be a broken ankle.

My doctor, family practitioner Gregg A. DeNicola in Yorba Linda, says I’m lucky: I made matters worse by toughing it out, but I don’t seem to have caused myself any permanent complications. Some of his other patients who denied or ignored injuries weren’t so fortunate.

One of his patients waited two weeks to seek treatment for an injured wrist. “He had a broken navicular bone, and if you miss that fracture, you can get vascular necrosis, which basically means you’re not getting enough oxygen to the bone,” DeNicola says. “That was last summer. He needed surgery, and he probably will still be in a cast for several months.”

He told me other horror stories about neglected injuries: knee fractures that ultimately needed plates and screws to repair, joints that unexpectedly dislocated or froze up completely.

But those cases are relatively rare, he says, even though injuries aren’t at all uncommon in his patients who make a special effort to stay fit. Running, aerobics, weekend softball and lunch-hour basketball, biking, hiking, soccer and other activities all may make a person more fit in the long run, but those who exercise regularly are also more likely to be injured than their couch-potato counterparts.

The saving grace is that body-conscious types also tend to seek treatment promptly, thereby reducing their chances of complications.

“It’s funny--I was talking to a med school classmate who now practices in Nebraska, and he says people there wait until they’re half dead before they break down and go to the doctor,” DeNicola says. “And when they do, they don’t want to hear the medical terms for what’s wrong with them. They just want to get better.”

Orange County patients, DeNicola says, not only go in right away, but they also are likely to mention specific medical terms even before their doctors do.

“I get a lot of people who say, ‘I think I have a meniscus tear,’ or ‘Do you think it could be a rotator cuff problem?’ A lot of them have read about sports figures who’ve had certain injuries, and they think, ‘Hey, that sounds just like mine,’ ” says DeNicola.

They may well be right, he says. “Even casual athletes can suffer the same kinds of injuries the professionals do. And with a lot of these things, being in good shape isn’t going to help. If you zigged when you should have zagged, you can get hurt.”

Injuries to the ankles and knees are far and away the most common, he says, followed by lower back and arm and shoulder injuries.

DeNicola, who is also a clinical professor of family practice at UC Irvine and the University of Southern California, says you don’t necessarily have to drop everything and run to the doctor the minute you’re injured.

“I can’t really think of anything except a dislocation or a bone sticking out where it would be wrong to wait for 24 hours,” DeNicola says. “Put ice on it--I recommend 20 minutes on, 20 minutes off--to reduce swelling. Elevate the injury if you can. After a day, you should switch to moist heat. It may be even more sore and swollen the next day. If it really bothers you, you should call the doctor.”

Some warning signs: Profound swelling usually means trouble, DeNicola says. And if you have tenderness in addition to pain, that could also be a problem. “Pain is subjective,” he says. “But tenderness--when it hurts to touch it--is more objective. That probably means it’s worth having it looked at.” If a joint is unstable, that may mean tendon or ligament damage, which could lead to dislocation, he says.

One-fourth to one-third of all ankle injuries beyond simple sprains still have some symptoms a year later, DeNicola says, “Primarily because they don’t get checked early enough.”

And with children, early treatment is even more crucial. “For kids, take all that and multiply it by 100,” DeNicola says. “Kids may not complain as much, but if they do have a fracture or something like that they’re much more likely to have problems. So it’s always better to have it checked.”

OK, I’ve learned my lesson. Meanwhile, I’m concentrating these days on upper-body workouts--on crutches.