If you’re single and grouchy, there might be some science behind it. While sex has many different connotations, meanings and implications, the science behind it is the same.
We all know to partake in regular physical activity to stay in better shape, lose weight, and reduce stress — but what about regular sex?
The benefits of sex don’t just come from your floor-shaking orgasm — there is a long list of positive scientific benefits behind your favorite nighttime activity. When we are done with stress-filled days, we often feel we need some kind of release and comfort. Tend to reach for nutritionally empty, sugary foods after a long day at work? Science has shown that this may give you close to the same neuronal effect as being intimate with another person. 
Besides staying lean, check out the following 9 benefits that regular sex can have — you may want to rethink your game plan!
1. More Restful Sleep
Since sleep loss is cumulative, and most of us do not get enough shut-eye, it is worth noting that regular sex helps us find more restful sleep.
Sex releases the hormone oxytocin, which decreases the production of stress-inducing cortisol. You’re left feeling more relaxed, making falling asleep easier. (2) With only about 50 percent of us get enough sleep, it might be time to swap counting sheep for a more physical nightcap. 
2. Improved Mood
Researchers have found that sex activates a part of the brain that is also activated when doing other pleasurable activities, like eating dark chocolate or playing with a cute puppy. 
Science (more specifically) says that there is increased dopamine transmission in the nucleus accumbens (the pleasure center of the brain) when we partake in sexual activity.  As good a reason as any!
3. Pain Relief
Our hormones run our lives (especially when we’re younger). With that in mind, it’s important to note that regular sexual activity can release a slew of beneficial, pain-relieving hormones, leaving us feeling better than before we started. 
The next time you reach for the Tylenol, head in between the sheets instead. Intercourse was shown to relieve the pain from migraines and cluster headaches, according to a study published in the journal Cephalalgia. “There’s a [portion] of patients with migraines, about one-third, who experience relief from a migraine attack by sexual activity,” explained researcher Stefan Evers, a neurologist and headache specialist from the University of Münster. (7)
4. Helps Reduce Risk Of Cancer
While I do not want to overstate the reduction here, it is still worth noting that some studies back this point up. One of the most convincing studies showed that more frequent ejaculation correlated with a decrease in prostate cancer risk.  In this study, ejaculating 21 or more times per month was associated with a lower risk of developing cancer.
For women, some sources even report that sex may be able to help lower the risk of breast cancer.  These studies both use correlative means, not causative mechanisms, so the exact scientific reasons behind these lowered risks remain murky.
My guess would be that sex helps to lower anxiety and stress, which should definitely help to lower your risk of developing cancer. While there are plenty of other measures you should take to lower your risk of developing cancer, like improving your diet and getting regular exercise, it also makes sense to incorporate more frequent sexual activity.
5. Reduces Your Chances Of Getting Sick
Surprisingly, some studies have found that we are much less likely to get a cold or the flu if we are having sex regularly. Pretty amazing, right?
Even having sex one to two times per week has been linked directly to higher levels of immunoglobulin A, or IgA, which is a substance found in saliva and the nasal lining.  Why is this important? IgA has been shown to help our immune systems fight off common illnesses like colds and flu. 
6. Improves Your Brain Power
This may be a good benefit to mention to your significant other. Scientists have found that more neurons are present in the hippocampus when you partake in more regular sexual activity.  That means more sex and more brain power. Not a bad combination.
Some studies even go so far as to suggest that certain brain activities (like analytical thinking) may be improved with more frequent sex.  Being a big nerd myself, this point might be my favorite reason to lead a more active sex life.
7. Improves Overall Fitness Level
While it’s not exactly the same as hitting the treadmill or lifting heavy weights, sex does lead to an improved fitness level. While sex does not burn as many calories as we might have been led to believe, 30 minutes of sexual activity can burn more than 100 calories. 
This doesn’t mean you can completely skip the gym, but it does give you some extra incentive to spend more time in the bedroom. Remember — every little bit helps!
8. Reduces Your Risk Of Heart Disease
Similar to my earlier point about cancer reduction, this benefit should not be overstated, but studies do show a lower risk of heart disease in those who enjoy sex more regularly. Specifically, researchers found that having sex just twice per week can cut the risk of heart disease by a whopping 50 percent! 
While certainly not the only lifestyle intervention that should be considered when looking to lower one’s risk of heart disease, having frequent sex certainly isn’t the worst thing for your heart health. Some studies also seem to support the idea that more frequent sex can also help lower one’s risk of heart attack, as well.
9. Lowers Blood Pressure
Since many in our country are afflicted with high blood pressure, this is a particularly important point to note.
High blood pressure, however, affects blood flow to the pelvis and can have an impact on the sex lives of both women and men. Women who already have high blood pressure may have a lowered libido, while men are twice as likely to lose their erection compared with those who have normal blood pressure. [16, 17] Just another reason to maintain an active sex life!
There you have it, nine reasons to incorporate more sex into your daily life. Most couples report that, on average, they have sex once a week. Experts agree that this is a good amount to keep most happy, with no additional benefits being observed at higher frequencies. 
So if you’re in a bit of a slump, send this article to your partner and see how they respond! You might just improve your health in a really fun way! And if you’re single, don’t worry — some studies show that masturbation may help lower the risk of certain forms of cancer.  Sex (whether alone or with a partner) helps us feel more relaxed, less stressed, and happier. And that can go a long, long way!