Here are a few food and exercise tips to help improve your sex life just in time for Valentine's Day.

NOSH ON PUMPKIN SEEDS

Pumpkin seeds are rich in the mineral zinc and may increase testosterone, which increases sexual desire in men. There are several studies, including one published in the Annals of Internal Medicine, showing that men with sexual dysfunction who were undergoing hemodialysis and receiving zinc had an improvement in potency, libido and frequency of intercourse not found in the placebo group. While there has not been a direct link to an improved libido in the average person, pumpkin seeds are certainly worth a try.

MUNCH ON DARK CHOCOLATE

Phenylalanine is an amino acid found in chocolate that raises the body's endorphins and produces dopamine, the brain chemical that surges during orgasm. According to a study published in the Journal of Proteome Research, eating about an ounce and a half of dark chocolate a day for two weeks reduced levels of stress hormones and other stress-related biochemical imbalances in people who rated themselves as feeling highly stressed.

In addition to phenylalanine, chocolate contains a number of chemicals that affect brain activity. One of these is tryptophan, the building block of serotonin, which is a relaxation-inducing neurotransmitter that, in large doses (chocolate has small amounts), causes elated or ecstatic feelings. Scientists have also isolated a substance that stimulates the same brain cell receptors as THC, the psychoactive substance in marijuana that induces feelings of euphoria. Furthermore, chocolate contains phenyl-ethylamine, a brain chemical known to promote feelings of attraction, excitement and giddiness.

GET FIT

If you want to increase your "love" factor, get out and exercise. Research indicates that exercise and increased physical activity improve your sex life. An article in the Electronic Journal of Human Sexuality reported that people who exercise often feel better about themselves, believe they're more attractive and enjoy sex more than those who don't. And another article in the Annals of Internal Medicine associates physical activity with a lower risk for erectile dysfunction. An article appearing in the Journal of Sexual Medicine found that physical inactivity hampers erectile function, and experimental and clinical exercise interventions have been shown to improve both sexual responses and overall cardiovascular health.

TRY YOGA

Speaking of exercise, I must say that doing yoga with your partner can be sexy. It's hard work; your energy levels are boosted; you increase blood flow; and you can see your partner in an entirely new light just by watching him or her do yoga poses. To get started, there are some great DVDs such as "Shiva Rea: Flow Yoga for Beginners."

ENJOY WATERMELON

According to a recent study from researchers at Texas A&M's Vegetable and Fruit Improvement Center in College Station, watermelon contains ingredients that create "Viagra-like effects to the body's blood vessels and may even increase libido."

EAT MEDITERRANEAN

A review article appearing in the scholarly journal Public Health Nutrition found that for obese men, eating a Mediterranean-style (e.g., fish, whole grains) diet and engaging in regular exercise can help to reduce sexual dysfunction over time.

DRINK GREEN TEA

It's never a good idea to have bad breath, but on Valentine's Day it can really interfere with romance. According to research reported in the Journal of Nutritional Science and Vitaminology, drinking a cup of green tea can help. Green tea has polyphenols, which have antimicrobial and deodorant properties.

SPICE THINGS UP

Add spice: Hot spices like cayenne, curry and cumin help warm things up. Chili peppers raise body temperature, flush cheeks and make lips swell.

Charles Stuart Platkin is a nutrition and public-health advocate, and founder of www.DietDetective.com.