Everyone deserves a great sex life, and the gift of sex should be available to everyone to enjoy. Unfortunately, low sexual desire is a very common problem affecting many marriages and relationships. When sex is happening and when it's functional and pleasurable, it accounts for about 15 to 20 percent of marital satisfaction. However, experts also point out that, when it is absent from a marriage or when it is conflicted, it becomes disproportionately important, accounting for up to 70 percent of marital unhappiness.
Thus, low libido and sexual dysfunction can have a profound effect on not only one's sex life but also one's relationships. Stop and ask yourself if you have been struggling with any of these thoughts about sex:
Of course, there can be rather profound reasons for the above - past abuse, cheating, etc. - and quite often physical issues - diet, hormones, lifestyle, weight, etc. But sometimes it can be as simple as the fact that we have forgotten the advantages of sexual intercourse. It is easy to arrive at the point where you ask, "Why am I doing this anyway?" Well, one answer is that you are doing it for yourself - or should be at least. Don't believe me? Well, check out these fantastic reasons a woman needs regular sexual activity:
NOTE: Peak Testosterone already has a page that on How Sex is Good for Men. However, I read that and felt that another motivational page was really necessary more from a woman's standpoint.
1. Weight Loss. What burns 69 calories and is a lot more enjoyable than pilates or yoga? Researchers found that during the typical bedroom session, the women burned 69 calories and the man 101.  Of course, with a little more effort a women can compete with guys and get calorie levels up to 100 as well.
100 calories per day may not sound like much, but it translates to 10 pounds of fat per year. Most people gain weight by overeating about 100 calories per day. So, simply by adding some extra bedroom time to your day, you can likely maintain your weight. The same study also found that intensity levels on average were moderate as well, making it comparable to many other forms of exercise.
2. Keeping Committed Relationships. Some research shows that committed relationships tend to falter and in some cases break up due to lack of sex. Although rarely is "lack of sex" or "sexual incompatability" cited as the primary reason for divorce or separation, some experts see it as a major contributor. In fact, there is a term for this on the traditional side of the world: "sexless marriages." What is the threshold for a "sexless marriage?" Would you believe ten times per year?!? That's Gandhi territory if you ask me!
Whatever you want to call it, it's tough going for most men and women. Professor Denise Donelley, who has studied sexless marriage extensively, states: "Are people in sexless marriages more likely to get divorced? In my studies, as well as others, people in sexless marriages report that they are more likely to have considered divorce, and that they are less happy in their marriages. Some of our former respondents have kept in touch with me, and the happiest ones are actually those that have moved on to other partners. It may be that lack of sex is a signal that all intimacy in a marriage is over, and that both would be happier in other situations." 
3. Depression. An orgasm floods you with a variety of neurotransmitters including dopamine, vasopressin, oxytocin, prolactin and many more. This would seem a fairly obvious way, in general, to renew the brain, boost mood and lessen depression. While it is somewhat of a chicken and egg thing, there is one study of college women that concluded that "the women with depressive symptoms reported more inhibited sexual arousal, more inhibited orgasm, more sexual pain problems, and less sexual satisfaction and pleasure than control participants. Novel to this study, the women with depressive symptoms reported greater desire for sexual activity alone (masturbation) than the nondepressed women." 
4. Relationship Quality. What do most women want from a relationship? How about "Satisfaction, Intimacy, Trust, Passion and Love?" Most women would love a relationship that is all about those five foundational principles and researchers actually have a measure of this called the Perceived Relationship Quality Components (PRQC) Inventory. Satisfaction, intimacy, trust, passion and love are just different dimensions within this kind of survey and researchers found something very interesting: only sexual intercourse improves these PRQC dimensions.  Other sexual behaviors such as oral sex and masturbation just do not do as well.
NOTE: Several studies show similar results for men's related issues as well, i.e. that sexual intercourse beats all other forms of intimacy. For example, one study showed that only sexual intercourse improves baseline testosterone levels in men. See #1 in my link on How Sex is Good for Men for the study.
5. Skin. Many studies show the power of DHEA (dehydroepiandrosterone) in restoring women's health, including mood, immunity and many other factors. And guess what is one of the best natural ways to increase DHEA? You guessed it - an orgasm! Dr. Eva Cwynar states that DHEA levels in women actually increases five times over baseline pre-orgasmic levels.  This is excellents news, because DHEA is excellent for the skin and has many other anti-aging properties. Studies show that the skin improvements start at the genetic level, i.e. favorably turning on and off genes that will improve skin tone and aging. 
6. Migraine Relief. There are about three times as many female migraine sufferers as male.  Of course, when a migraine has begun, the last thing one thinks about is sex. However, researchers found that over two thirds of migraine sufferers actually experienced moderate to total relief from making love!  This rivals many pharmaceutical solutions! (Be careful, because some experienced worsening of symptoms.)
GUEST AUTHOR: Many thanks to Cristina C., certified Yoga Nidra Instructor, Hypnotherapist and Life Coach.
2) Steroid Biochem Mol Biol, 2008 Dec, 112(4-5):186-93, "Pangenomic changes induced by DHEA in the skin of postmenopausal women"
3) J Clin Endocrinol Metab, 2000 Oct, 85(10):3561-8, "Effects of dehydroepiandrosterone on collagen and collagenase gene expression by skin fibroblasts in culture"
4) http://well.blogs.nytimes.com/2009/06/03/when-sex-leaves-the-marriage/?_php=true&_type=blogs&_r=0 , "When Sex Leaves the Marriage, By TARA PARKER-POPE JUNE 3, 2009"
5) The Journal of Sex Research, 2002, 39(4), "Sexual functioning and selfâ€reported depressive symptoms among college women"
6) Journal of Sex & Marital Therapy, 2007, 33(4), "Women's Relationship Quality is Associated with Specifically Penile-Vaginal Intercourse Orgasm and Frequency"
7) PLoS ONE, 8(10):e79342, "Energy Expenditure during Sexual Activity in Young Healthy Couples"
9) Cephalalgia, Feb 19 2013, "The impact of sexual activity on idiopathic headaches: An observational study"