9 Reasons Why Overdoing it at the Gym is Hurting You

9 Reasons Why Overdoing It at the Gym Is Hurting You9 Reasons Why Overdoing It at the Gym Is Hurting YouBy Leslie Goldman

We'd never advise you to ditch your regular workout sessions, but too much gym time can weaken your bones, ruin your sleep, and affect your chances of getting pregnant.

1) Your Bones Could Get Battered

Not all cardio was created equal. Weight-bearing activities such as walking, running, basketball and dancing are the smartest, most effective ways to build bone density. But if you start to experience pain in your shins or feet, you may need to lighten up -- heavy pounding can result in stress fractures, tiny cracks in the bones of your feet and lower legs. Biking and swimming aren't any better. Non-impact activities don't build bone strength at all. In fact, a recent Journal of Sports Medicine and Physical Fitness study found that competitive cyclists had lower bone density than non-athletes, thanks to all that time in the saddle. Pete McCall, an exercise physiologist with the American Council on Exercise, suggests changing up your cardio routine, incorporating weight-bearing activities that require you to move in multiple directions with a full range of motion. Jog outside one day, take a Zumba class the next, and join a softball league for the weekends. Don't forget to lift weights, a stellar move for strong bones.

2) You Can Lose Sleep

After a marathon day at the office, 9 p.m. may be the only time you have left to squeeze in a workout. But a heavy sweat session too late at night will sabotage your sleep. "Your body releases hormones during exercise, including adrenaline, that remain elevated for at least a couple of hours, making it harder to fall asleep," explains McCall. His rule: Give yourself at least two hours to cool down, plus a minimum of six to seven hours of sleep, which is necessary for rebuilding muscle. If you need to wake up at 6 a.m., don't work out after 8 the night before. A solid night of sleep can also keep your appetite in check. A lack of sleep stimulates the production of the hormone that increases the desire for food while decreasing levels of your body's natural appetite suppressant. A good night's sleep will make you feel rested and less hungry.

3) You Could Be Hurting Your Chances of Getting Pregnant

If you're trying to get pregnant, you may have to tone down your workouts. Hardcore exercise can disrupt ovulation, leading to loss of periods. A 2009 study in Human Reproduction found that high frequency and high intensity exercise can triple a woman's chances of infertility. Cardio queens having trouble getting pregnant should try dialing back their workout intensity for three months, suggests Alice Domar, Ph.D., executive director of the Domar Center for Mind/Body Health at Boston IVF and author of Conquering Infertility. "Keep your heart rate below 110," she says, and change up your routine. "Walk instead of run, swim instead of doing aerobics. Try yoga." And eat an extra slice of pizza! Research suggests that gaining just six to eight pounds (if you're underweight) might be enough to boost your odds of conceiving.

4) You Can Sabotage Your Abs

If 30 minutes on the elliptical a day keeps the muffin top away, then surely 60 minutes will shrink the entire muffin, right? Wrong. Gym rats log endless hours on the elliptical with the hope of fitting into their skinny jeans, but their efforts may be conspiring against them, McCall says. When the body is physically or emotionally stressed, it pumps out cortisol, a stress hormone that causes belly fat to plump up. The effect is magnified in exercisers who skimp on calories -- the body is forced to rely on the protein in muscles for energy, storing the carbs you eat as belly fat. Banish that bloated tummy by eating a balanced diet, cutting back on your workouts and adding interval training. If you normally spend an hour on the Stairmaster at the same intensity level, try a 40 minute session with a twist. Alternate two-to-four minutes of hard climbing with two-to-four minutes of easy climbing.

5) You'll Miss the Added Benefit of the Great Outdoors

All those hours spent under harsh fluorescent lights staring at giant metal exercise equipment can be downright depressing. A 2010 Environmental Science & Technology Journal study found that people who are active in "green" spaces -- jogging in the park, hiking in the mountains -- are happier, less stressed and enjoy healthier self-esteem. Adding water to the equation (like biking along a lake) boosts the effects even more. Broaden your workout repertoire from the confines of spin class and try an outdoor boot camp, hiking, horseback riding, waterskiing or simply walking.

6) Your Immune System Can Weaken

While moderate exercise is phenomenal for the immune system, too much training is known to diminish your defenses, leaving you prone to colds, flus and the other viruses lurking on the dumbbells at your gym. (A Clinical Journal of Sports Medicine study reported that the virus causing the common cold can be found on 63 percent of exercise equipment in the gym.) You might even notice that scratches and cuts take longer to heal. Rather than go all-out every day of the week, try alternating harder workouts with moderate sessions throughout the week to give your body a chance to recover. "That's what top athletes do," McCall notes. If you usually run an hour a day, do interval training two to three days out of five. Run hard for three to five minutes and then walk fast for three to five minutes. Repeat.

7) You Can Flatten Your Curves

We'd never suggest tailoring your workouts solely for men's enjoyment, but surveys consistently reveal that men prefer ladies with curves to women with twig-like figures. Slogging away on the treadmill day in and day out can melt away your hips and breasts, so back off a bit if showing off toned, sexy curves is one of your goals. Maybe now is the time to switch to walking, yoga or other lower-intensity work outs. Think about voluptuous sex symbols like Scarlett Johansson, Kate Winslet, Jennifer Lopez, Christina Hendricks, Tyra Banks and Kim Kardashian -- not a bony hip among them!

8) You Could End Up in Early Menopause

You just can't win: A new Japanese study found that women who exercise eight to 10 hours per week are 17 percent more likely to start menopause early compared to sedentary women. (Ditto if you eat a heart-healthy diet.) The theory: Physical activity reduces circulating estrogen levels, which can lower the risk of breast cancer but increase the risk of heart disease and osteoporosis. Experts don't suggest quitting exercise as a way to stave off menopause (it's going to happen sooner or later), but if you're concerned, speak with your doctor about modifying your workout.

9) Your Self-Esteem Can Suffer

All those mirrors in the gym are supposed to help you maintain proper form, but for many women, they reflect a distorted image. In a study in the journal Health Psychology, researchers followed 58 women after they exercised in front of either a mirror or a non-mirrored wall. They found that women who faced the mirrors felt worse about their bodies. If seeing your reflection causes you to obsess over your weight, stick to machines facing your fellow exercisers. In group classes, choose a spin bike or yoga mat towards the back of the room. If these negative thoughts ever feel overwhelming, talk with your doctor or therapist to pinpoint more productive ways to heal your body image.

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