Research shows that your stamina and strength are controlled by four key hormones. Learn how to turn up their power.
Your hormones are like a team, working together to give you energy. “There are anabolic hormones—including insulin and your thyroid hormones—that help your body create and store the molecules it uses as fuel. And catabolic hormones, such as cortisol and adrenaline, which enable your body to use that fuel,” explains Deena Adimoolam, M.D., a spokeswoman for the Hormone Health Network of the Endocrine Society. (Take advantage of these five hormones to sculpt your best body ever.)
But certain factors, including diet and stress, can upset this precise operation, making your energy levels plummet. Fortunately, by using a few simple strategies, you can sync them again—and become even stronger. Here’s how.
“These are crucial because they help regulate the body’s metabolism—in other words, its ability to make, store, and use energy,” says Dr. Adimoolam. But their production can be inhibited by products we use every day. Several groundbreaking studies have found that bisphenols and phthalates—two chemicals in many plastic products, like water bottles and food containers—can throw off thyroid function, which may cause fatigue. People with higher levels of these chemicals—especially a phthalate known as DEHP, found in plastics used for tablecloths and shower curtains—had lower levels of thyroid hormones, according to the journal Environmental Health Perspectives. BPA substitutes like BPS and BPF (often used in products marked BPA-free) can also disrupt thyroid hormones, the journal Environmental Pollution reported. (See: The Scary Truth About BPA-Free Plastics.)
To protect your thyroid hormones, avoid using plastic products whenever possible, says John D. Meeker, the lead author of the first study. Opt for glass, metal, or paper instead. And if you have to use a plastic food or drink container, never heat it—the high temperatures can cause BPA and other chemicals to leach into your food.
“This hormone pulls glucose from the blood and into the muscles, which use it for fuel,” says Dr. Adimoolam. But you need the right amount. Chronically elevated levels may lead to insulin resistance and eventually type 2 diabetes, she explains.
For optimal insulin—and energy—levels, do an hour of exercise three or four times a week. Cycling for 60 minutes improved adults’ insulin sensitivity for two days afterward, a study in the journal Clinical Science found. “When you exercise, the muscles draw glucose from the blood to use for energy without needing insulin,” says Labros Sidossis, Ph.D., the study author. That helps keep the hormone in a healthy zone so that it functions better when you do use it. (Related: Indoor Cycling Instructors Reveal Their Go-To Tricks for Powering Through Class)
Yes, it’s the stress hormone, but cortisol also regulates alertness. Levels of it surge in the morning to help you wake up, then gradually taper off over the course of the day, briefly spiking whenever you need more focus. Problems like a poor night’s sleep and chronic stress can throw off that natural rhythm, though, says Frank Lipman, M.D., the author of How to Be Well. When you don’t get quality z’s, for instance, your body may try to compensate by increasing its cortisol production throughout the day. By nighttime, your levels may remain up to 45 percent higher than normal, making it harder to doze off and creating a vicious cycle.
Constant stress—the kind you feel when you’re going through a demanding time at work—can also result in higher-than-normal cortisol levels. “That means you’ll feel exhausted in the morning and wired at night,” Dr. Lipman says. (Use these 5 strategies to reduce stress after a long day and promote better sleep at night.)
To get on track, stick to a regular sleep schedule and minimize stress. Also, try taking adaptogens, compounds in plants that help regulate the adrenal system, says Dr. Lipman. “Adaptogens sense imbalances in hormones and naturally correct them,” he says. Look for a supplement called ashwagandha root at health-food stores, and take 300 milligrams twice daily, Dr. Lipman advises. (Check with a doctor first; the supplement interferes with some meds.)
This is the fight-or-flight hormone, and it’s what makes your heart begin to pound just before a job interview, a first date, or the start of a big race. “Adrenaline gives the body immediate energy. It speeds up the heart rate and sparks cortisol production,” says Dr. Lipman.
But adrenaline can also be triggered by smaller daily stressors, as when you’re running late to work, Dr. Lipman says. That’s when it can cause problems. “If adrenaline spikes throughout the day, it makes you feel depleted rather than energized,” he explains. To tone down the adrenaline response, he suggests spending at least 10 minutes each day on a calming activity, such as yoga, knitting, or listening to music. Eventually your adrenaline will stop spiking as often or as high, and your energy will stay steady.