by Kelly James-Enger

Looking for a way to boost your motivation, enhance your performance at the gym or recover more quickly from a hard workout? Believe it or not, the answer may lie not under, but inside, your nose.

Scent may the most neglected of the five senses, but it’s arguably the most powerful. “The part of the brain which smells—the olfactory cortex—is actually part of the limbic lobe, or the emotional brain,” says Alan Hirsch, MD, neurologist and psychiatrist at the Smell and Taste Treatment and Research Foundation in Chicago. “So the quickest way to induce change is with smell. You smell something and you immediately decide ‘I like it’ or ‘I don’t like it’ and then you figure out what it is.”

So perhaps it’s not surprising that aromatherapy and related products are a booming business in the United States—Americans spent more than 400 million dollars a year on everything from scented candles to essential oils designed to lift their spirits, relieve anxiety, boost energy, and even enhance romance.

While studies have shown that odors can affect people’s behavior and mood, researchers aren’t sure exactly why this is, says Hirsch. It may be due to a psychological effect or to the fact that smells can produce what’s called olfactory-induced nostalgia—like when you smell a whiff of cotton candy and remember your first trip to the fair. It may also be that smells have a physiological effect on the brain. Regardless of how they work, researchers have found that certain smells can improve mood and ease pain. A number of studies have proven that certain smells reduce anxiety and enhance well-being; another found that the smell of peppermint relieved headache pain. And research published last year found that the smell of lavender reduced feelings of depression.

Certain smells may even help you lose weight. Consider the study that Dr. Hirsch conducted several years ago with over 3,000 subjects. Each person was given samples of peppermint, green apple or banana scents and told to sniff the scent three times whenever they felt like eating. On average, people with a normal sense of smell lost five pounds a month, or a total of 30 pounds over the course of 6 months.

“We found the more frequently they used the odors, the more weight they lost,” says Hirsch, who documented the results in his book Scentsational Weight Loss. “We’re not sure why it works. It may be that the odors acted as a displacement mechanism, so maybe instead of grabbing the doughnut, they grabbed the inhaler. Or maybe the act of sniffing reminded them not to eat. Or maybe the odors acted to satisfy cravings.”

It’s clear that if you like the smell of something—whether it’s freshly-baked bread or newly mown grass—then being exposed to it will probably improve your mood. There’s now evidence that smelling certain odors before or during your workout may boost your performance as well. Hirsch conducted a study several years ago where people pedaled stationary bikes while wearing surgical masks that had the scent of buttered popcorn, the scent of strawberries, or no scent on them. He found that if people liked the smell they were exposed to, they pushed themselves harder and burned more than 10% more calories than the control group.

Other research conducted this year confirmed that smells can have a positive outcome on performance. Physiological psychology professor Brian Raudenbush, Ph.D. of Wheeling Jesuit University in Wheeling, West Virginia knew that certain odors could influence mental performance. To test physical performance, he had athletes perform pushups, run, do grip strength tests and shoot free throws both when exposed to peppermint and to no smell. The athletes performed more pushups, ran faster, and had stronger grip strength when they were smelling peppermint; there was no statistically significant difference in the number of free throws.

Raudenbush theorizes that the smell of peppermint has a mood-lifting effect which leads to higher athletic performance. “Any time you can influence someone’s mood and get them in a better state of mind, they’re willing to push themselves a little bit further,” says Raudenbush. In an earlier study, he exposed people to three different scents—peppermint, jasmine, and a “bad” smell of dimethyl sulfide (which smells like a locker room) and had them perform a 15-minute stress test on a treadmill. Jasmine had no effect; peppermint produced an improved mood and an increased belief that they had performed well; and the bad smell made people feel more fatigued and less energetic.

So, how can you use these studies to benefit you own workouts? First, determine what scents you enjoy. If you can find certain candles or fragrances your like, pick some up to use as mood-lifters. For even more results, consider exploring the field of aromatherapy, which goes beyond simply smelling pleasant odors—aromatherapists use essential plant oils for medicinal or therapeutic purposes. “There is a psychological effect, a physiological effect, and a pharmacological effect because an essential oil is a chemical and it will cause changes in the body when it is absorbed and carried through the bloodstream,” explains Janis Burke, a certified aromatherapist and preceptor at Washington State University in Yakima.

While essential oils may share the same names as some of the candles or other scented products you may buy, the former is much more concentrated, says Burke. And even the names can be confusing—for example, there are several varieties of lavender which all have different properties. With aromatherapy, you take a drop or two of an essential oil and dilute it in a carrier oil like grapeseed. It’s then placed on or massaged into the skin, inhaled, or placed in a diffuser to allow it to be carried into the air.

While there are hundreds of essential oils, each has its own unique characteristics and properties. For example, Roman chamomile helps ease muscle spasms while German chamomile reduces inflammation and swelling. True lavender is a natural pain killer and has a relaxing effect; a recent study found that people who were exposed to lavender after exercise had lower blood pressure and slower heart rates than those without it. Lemongrass is good for reducing pain and easing stress while bergamot has an uplifting effect. Peppermint and black pepper are both stimulating oils and can be used for combating fatigue.

Keep in mind that any scent you enjoy is likely to improve your mood and enhance your performance when you exercise. If you use a smell you like, “you’ll start to associate a better mood with working out,” says Raudenbush. And don’t forget that you can use smell to help wind down at the end of a stressful day, too—consider scented candles or vanilla or lavender incense. By creating a positive, pleasant environment, you’ll also help trigger that sense of relaxation when you need it. •