5 'Good' Habits that Hurt You: Efforts to do everything right may be sabotaging your fitness and well-being - Health

When it comes to our health, some of our most cherished assumptions about eating, working out, body fat and relationships are wrong. In fact, some of our "healthy" convictions can be downright dangerous. Here are five of the most commonly made mistakes.

1. "I rarely miss a day at the gym."

Everyone needs a break from their workout routine -- even Olympic athletes -- for two reasons. First, your body needs new challenges in order to maintain or improve fitness. Second, overtraining can lead to muscle aches and tears, joint injuries, lack of energy, unrelenting fatigue, decreased immunity, even depression, says Jack Raglin, Ph.D., associate professor of kinesiology at Indiana University, Bloomington, who studies the psychological and physical effects of exercise overload. "If you never miss a day at the gym, that means there's nothing in your life that's more important," he says.

Instead If you're gearing up for an event like a 10k, you might push yourself harder than usual. At other times, give yourself a break from the gym. Walk outside. Schedule days off and enjoy some social time with friends. Flexibility is key. The truth is that going as long as a week without breaking a sweat won't impact your fitness significantly -- but going too long without a break from your workouts definitely will. "It's a case of diminishing returns," Raglin says. "Doing more and more -- without building rest and recovery into your routine -- does you less and less good."

2. "I don't eat sweets."

Cutting out candy is fine, but trying to eliminate all sweets can backfire. That's because you're clashing with your body's basic programming. "Our ancestors needed a sweet tooth to know which fruits and vegetables were ready to eat," says Janet Walberg Rankin, Ph.D., a professor of nutrition and exercise science at Virginia Polytechnic Institute in Blacksburg. "So, as humans, we're hard-wired to want sugar." If you attempt to eliminate all sweets from your diet, eventually your inner cave woman will take over and you'll hit the cookies, hard.

Instead Elizabeth Somer, M.A., R.D., author of The Origin Diet (Henry Holt, 2001), says that you can fit any treat into your diet, but your best bet is to eat healthier sweets: a bowl of strawberries with chocolate sauce, or a small portion of something truly decadent, such as a slim slice of cheesecake or a single gourmet truffle. That way, you'll satisfy your urge and be less likely to binge.

3. "I've gotten my body fat down to 18 percent."

Many women substitute control over diet and exercise for control over some other aspect of their lives, like their jobs or their relationships, says Ann Kearney-Cooke, Ph.D., director of the Cincinnati Psychotherapy Institute. And it's a habit that can be downright addicting. "Whenever you get extreme about something, whether it's work or working out, that should be a warning to you," she says. "you might be using that activity to create a change in another part of your life -- and that strategy never works." Kearney-Cooke says some women instinctively focus on what they can control, like what they eat or how they work out. Then, with each victory achieved over their bodies, they're encouraged to do even more.

Whittling away at your body fat can be dangerous: Fat insulates nerve cells and internal organs and is necessary for the formation of hormones like estrogen. When body fat dips too low, you go into famine mode, which effectively shuts down all nonlife-supporting functions, like ovulation and building new bone. In many cases, says Indiana University's Jack Raglin, the damage can be permanent: Estrogen is involved in the creation of bone, which is [mostly] completed before you're out of your 20s," he explains. "If you interfere with that, you could be in big [bone-density] trouble for the rest of your life."

Instead The key to keeping any goal on track is to see it as part of the bigger picture, Kearney-Cooke says. Remember that working out and eating healthfully are just two elements of a healthy life; they must be balanced with family, work and spirituality, since all are vital components to good health. "Ask yourself, 'What would happen if I didn't make this goal?' It shouldn't feel like the end of the world."

Instead of striving for an even more minuscule number on the body-fat monitor (or on the scale), put your emphasis on building muscle. "Most physically active women fall between 20 and 27 percent body fat," says Carol L Otis, M.D., a sportsmedicine physician in Los Angeles and author of The Athletic Woman's Survival Guide (Human Kinetics, 2000). "Everyone is different, though. If you are eating well and exercising regularly, your body will find its natural level -- and there is no advantage to going lower than that."

4. "I've cut way back on carbs."

Carbohydrates are vital to our diet -- despite what the high-protein proponents maintain. Carbs are the body's primary source of fuel -- for muscles and the brain. Eliminating carbs from your diet can lead to short-term memory loss, fatigue, lack of energy, and vitamin and mineral deficiencies, says Glenn Gaesser, Ph.D., a professor of exercise physiology at the University of Virginia and author of The Spark (Simon & Schuster, 2000). "The underlying problem with a high-protein diet is that there are a lot of very good, healthy nutrients packed into carbohydrates," Gaesser says. You're also missing out on fiber which is essentially what separates the "good" (complex, high-fiber) carbohydrates from the "bad" (simple, refined).