We know the excuses: Who has the time? I'm exhausted after working all day. I'll try again next week.

No, we're not talking about exercising (though you really should hit the gym for health and longevity sake). We're talking about sex.

Although sexual activity does decline in midlife, as illness and other factors can interfere with sexual health, a 2007 study by the New England Journal of Medicine found 73 percent of people age 57 to 64 were sexually active. More than half of 65-to-74-year olds and 26 percent of 75-to-85 year olds had an intimate relationship in the year prior to the survey.

"As boomers are getting older, they are less likely to accept that they are supposed to be sexless," said Dr. Janice Epp of the Institute of Advanced Study of Human Sexuality. "A lot of research is finding people are saying, ‘Nuh uh!'"

“I think one of the most common myths is that people stop having sex as they get older,” agreed Patty Brisben, the founder and chairwoman of Pure Romance, a company that specializes in selling sex toys and providing information on women's sexual health issues. “More often than not, sex over 50 is still something couples are interested in. They may just need the green light to start exploring again.”

There are several key factors that can make a couple to feel sexually stalled, Dr. Epp said. The first is a natural decline in energy levels, Epp said. "When you’re in your 20s you still have a lot of energy at 11 p.m., which is not necessarily true when you’re in your 70s."

The second is cultural: "When one hits a certain age, society tells us we’re no longer sexually attractive," Epp said, noting this is especially true for women. And not feeling sexy doesn't quite make you want to take a flying leap into the sack. "We need to understand that it’s OK to find pleasure in the bedroom in whatever way suits us best, no matter what stage of our lives we’re in," she added.

Finally, sex can become routine. "Like anything, the same sex with the same person can become boring," Epp told Huff/Post50. "The first 400 gazillion times it’s exciting, but after a while it gets to be routine."

Check out the slideshow below for seven other key culprits behind declining sexual activity, and how to overcome them.

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  • Culprit: Medication

    "Medications that are prescribed for stroke issues and heart issues can have devastating effects on sexual functioning," explains Dr. Janice Epp of the Institute of Advanced Study of Human Sexuality. In addition, researchers have found that a family of <a href="http://www.springerlink.com/content/0483x4276q80417q/" target="_hplink">antidepressants known as selective serotonin reuptake inhibitors (SSRI) can take the winds right out of your sails</a>. These drugs include brand names such as Prozac, Zoloft and Paxil.

  • Fix: Talk To Your Doctor

    Don't be shy -- talk to your doctor about how your prescriptions are affecting your sex drive. "There are a whole lot of new drugs that don't necessarily have those side effects, but it takes a lot of experimenting," says Dr. Epp. "Sometimes it takes three to four different tries to find the one that's best for you."

  • Culprit: Pain Or Discomfort

    "People of both sexes can develop pain disorders as they get older, and that can have a big effect on sexuality," notes Patty Brisben, founder and chairwoman of Pure Romance, a company that specializes in selling sex toys and providing information on women's sexual health issues.

  • Fix: Mix It Up

    Brisben suggests re-evaluating your definition of sex. "Being intimate does not necessarily mean having sex in the traditional sense," she says. Some solutions sensual touching and massages and mutual masturbation. Dr. Epp suggests looking into new positions. "Sit on a chair, try being in different positions," she says. "Side by side actually puts the least amount of stress on your joints."

  • Culprit: Lack Of Sleep

    The <a href="http://www.sleepfoundation.org/article/how-sleep-works/how-much-sleep-do-we-really-need" target="_hplink">National Sleep Foundation</a> recommends getting seven to eight hours of shut eye a night. But with the stress of work, kids, bills and, oh yeah, your marriage, who can think about fitting in time to have sex, much less sleep?

  • Fix: Plan Sex Dates

    For some couples the days of random romps may be behind them, and that's alright, says Dr. Epp. "Plan some sex dates around times that you know you feel more energetic -- it lets you look forward to it," she says. "Some people say, 'Sex should be spontaneous!' to which I say bullsh*t," she says, laughing. "You plan other things in your life and you don't complain about it. You can do the same with sex."

  • Culprit: Menopause

    Waning libido and vaginal dryness are two unpleasant side effects of menopause. With increased longevity, "women can now expect to spend a third of their lives in post-menopausal years," Brisben said. "So understanding how you're being affected by those changing hormones is essential."

  • Fix: Creams And Lubricants

    A dip in estrogen may lead to thinning vaginal walls and itchiness in the area. According to the Mayo Clinic, <a href="http://www.mayoclinic.com/health/vaginal-dryness/DS00550/DSECTION=treatments-and-drugs" target="_hplink">treatments can include </a>vaginal estrogen creams such as Estrace and Premarin; a flexible estrogen ring that is inserted; or estrogen pills, patches or gels.

  • Culprit: Avoiding Frank Conversations About Sex

    "I think if you're just now embracing this subject at or around age 50, you've got some catching up to do!" Brisben tells <em>Huff/Post50</em>. But it's never too late to start having a frank and honest conversation with your partner about what you want in bed.

  • Fixes: Accessories, Letters, Books, Therapy

    "I recommend having these conversations out of the bedroom and when you have some alone time," Brisben says. "Be open, be receptive and be ready to listen." Don't be afraid to bring some playfulness to the discussion. "Shop online for intimacy products together," Brisben suggests. Or write your partner a letter: "Tell them what you'd like to introduce into your intimate relationship." Another tact: Read sexy books together and share what interests you and what doesn't. "If you find these conversations are still hard to have ... a sex therapist or counselor is trained to help," Brisben adds.

  • Culprit: Not Addressing Problems Down There

    It's the one part of aging and sexuality that gets the most attention: erectile dysfunction, which is <a href="http://www.mayoclinic.com/health/erectile-dysfunction/DS00162/DSECTION=causes" target="_hplink">often rooted in some larger physical problem, including heart disease, high blood pressure, diabetes and obesity</a>, according to the Mayo Clinic. Medications and drug and alcohol use can also play a role.

  • Fix: Prescriptions, Pumps And More

    Ubiquitous ads promote the popular little blue pill to cure impotence, but there are <a href="http://www.mayoclinic.com/health/erectile-dysfunction/DS00162/DSECTION=treatments-and-drugs" target="_hplink">other treatments as well, including vacuum pumps, implants and surgery</a>, according to the Mayo Clinic.

  • Culprit: Thinking You Have To Be 'In The Mood'

    According to the movies or steamy prime time television shows, passion goes from 0 to 69 with a mere glance, a bitten lip or a bad pun. But "as we age, our bodies slow down and we have less energy," Dr. Epp tells <em>Huff/Post50</em>. "That's naturally occurring, but it can have an affect on our sexuality."

  • Fix: Learn The Difference Between Arousal And Desire

    Rethink the connection between arousal and desire. Tell your partner if you need more than the <a href="http://www.womansday.com/sex-relationships/sex-tips/sex-by-the-numbers-103274" target="_hplink">average 20 minutes spent on foreplay</a>.

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