If over-the-counter pain-relievers are becoming part of your exercise routine, you are overdoing it.

"Some people take these medications every day to treat muscle aches and pains associated with exercise," said Dr. John Cianca, a sports medicine expert at Baylor College of Medicine in Houston. "They may get some temporary pain relief, but the medications are actually covering up something that’s wrong in the body."

So how do you tell the difference between a simple sore muscle and an injury? "If something hurts for three or more consecutive days, or on a frequent basis, it’s best to see a doctor for an injury diagnosis," said Cianca. "But using a pain-reliever to treat problems that are recurrent or persistent will only cause you more problems in the long run."

In addition to "masking injuries," regular use of over-the-counter pain-relievers can cause stomach upset.

Don’t let your bathroom scale determine whether you are in shape. It is possible to be overweight and still achieve a high level of fitness.

"Too much emphasis has been placed on losing weight," said David Brennan, an exercise physiologist at Baylor College of Medicine. "We’re beginning to see exercise programs for overweight people that focus on improving their level of fitness. In many cases, this is accomplished even if they don’t lose weight."

Brennan believes fitness should be measured by how you feel, not how you look, since some people have a lack of control over their weight. "People are overweight not just because of overeating and inactivity," said Brennan. "Many people are genetically predisposed to being overweight, but that doesn’t have to prevent them from being in shape."

Research shows that overweight people who follow a regular exercise routine can have healthy cholesterol levels, normal blood pressure, and good cardiovascular health.

Eating energy gels can help recreational endurance athletes go the extra mile. Athletes who participate in activities like hiking, running, or cycling rely on the energy stored in their muscles to perform. After a while, that energy is used up. This is when new energy gels can help.

"Studies have shown that sports drinks taken during activity get into the bloodstream and provide an energy boost," said Dr. John Cianca. "The gels, which contain even more sugar and carbohydrates, have the same effect." That can make a big difference on a two hour run or in between sets of tennis. But Cianca says it is best to experiment with the gels, which are pudding-like in texture, during a short workout first to ensure they do not upset your stomach.

While exercise is great for the heart, it can take a toll on the soles—of your feet that is. "Feet are one of the most neglected parts of the body when it comes to fitness," said David Brennan, an exercise physiologist at Baylor College of Medicine in Houston. "Most people don’t think about taking care of their feet until they hurt. By that time, damage may have already occurred."

Using proper shoes for your exercise is the most important "step" you can take to avoid foot problems. "If you’re participating in several activities, you need more than one pair of shoes," cautioned Brennan. "Sport-specific shoes can help prevent injuries."

In addition, Brennan recommends always wearing socks to help absorb the shock of exercise and keep feet dry; clipping toenails because pressure from shoes can irritate nails, causing them to fall off, and rubbing or soaking feet after workouts. This helps to increase circulation and relax foot muscles. "Your feet might be sore after a workout, but they should not hurt," said Brennan.

Spinning is the latest craze sweeping America’s health clubs. While it might sound innovative, it is nothing more than a new workout on an old piece of equipment—the stationary bike. "Spinning is like an aerobics class on a bike," said Dr. John Cianca, a sports medicine specialist at Baylor College of Medicine. "The idea behind the workout is to increase the intensity of pedaling on the bike. It’s an excellent exercise for the heart, with virtually no impact on the joints."

Many fitness clubs have instructors who conduct spinning classes that work on cycling techniques and also incorporate other exercises while on the bike. Cianca said spinning is a good option for people just beginning an exercise program, since it is easy to learn and the intensity can be controlled with resistance levers on the bike.

Recreational athletes who rely on nutritional supplements to burn fat and build muscle may be setting themselves up for severe dehydration. "Athletes tend to stay right on the edge of being well-hydrated," said Dr. Lon Castle, a sports medicine expert at Baylor College of Medicine in Houston. "Some of these supplements can push people over the edge and lead to dehydration, which can cause serious health problems."

Creatine, which is produced naturally in the body, is one of the most popular supplements used by weight lifters, sprinters, and other recreational athletes. Castle says it has been shown to increase lean muscle mass in some athletes, but the associated dehydration dangers must be considered. "People who take supplements should ensure they are drinking a log of water—up to 10 to 12 eight-ounce cups a day," said Castle. "And if you experience persistent muscle cramps, that’s a sign that your body’s water level is low."