You know the signs: three hits of the snooze button, a must have second cup of coffee, and an unplanned nap on the train ride home. With almost every woman you know complaining of exhaustion, it's easy to write off sluggishness as an inevitable part of life. "Feeling tired constantly isn't normal—and it can take a huge toll on your well-being," says Woodson Merrell, M.D., the chairman of integrative medicine at Beth Israel Hospital in New York City. "It can kick up food cravings [contributing to weight gain], hinder your productivity, and even weaken your immune system." The obvious solution is to log more shut-eye each night, but sleep may be only part of a larger problem. Research reveals that the food we eat, people we interact with, and decisions we make can also influence our energy levels. We asked the experts how to tackle some of those hidden drains so you can have all-day stamina.

1. Energy Zapper

You're Faced With Too Many Options
From which coffee you order in the morning to the TV show you watch at night, you're faced with hundreds of choices every day. Weighing your options takes work, say researchers, which can lead to fatigue. According to a recent study in the Journal of Personality and Social Psychology, people who made a series of shopping decisions at a mall reported being more tired—and were less able to think clearly—than those who only browsed. What's more, "feeling overwhelmed can also lower your confidence levels and make you feel stuck," says Susan Nolen-Hoeksema, Ph.D., a professor of psychology at Yale University. So if you've spent your day negotiating, put off making any major life choices.

Fight Fatigue
To get through the day without becoming bleary eyed, avoid weighing every possibility, says Judith Orloff, M.D., the author of Emotional Freedom. For less important decisions, like what healthy entrée to order at a restaurant, zero in on two top contenders—the first dish that catches your eye, along with a standby—then consider the benefits of each.

For weightier issues, such as buying a home or selecting a graduate school, make a list of the pros and cons of each option, then sleep on it to allow your intuition to kick in. "Give yourself some time to process your decision," says Orloff. "Your gut instinct, which draws up unconscious memories, can help guide you."