Inflate your ego. Try this classic therapy trick: Grab a piece of paper and jot down seven things you like about yourself. Self-confidence equals increased energy.
Wear brighter colors. Vibrant greens and blues activate neurons in the brain that keep energy at its peak.
Do a puzzle. Pick something challenging. Problem solving stimulates brain cells, spiking your body's energy levels.
Do some cardio. Biking, running, and swimming all help to increase the number of energy-producing mitochondria in your cells.
Do the downward dog. Indian researchers found that men who perform yoga often experience less fatigue during cardiac stress tests than men who don't.
See a funny flick. A study in the journal Psychological Reports found that laughter pushes the energy-sapping compound neuroendocrine out of your brain.
Have a soundtrack. Play background music at your desk. You'll have less anxiety, a prime energy thief.
Get your stuff together. The more organized things are around you, the more mental and physical energy you can devote elsewhere.
Duck debt. Researches at Ohio State found that men who were stressed over their credit card debt had lower energy levels than guys with less debt or none at all.
Stay positive. Australian researchers found that men who had positive attitudes suffered fewer injuries and recovered from injuries faster than their darker—less energetic—counterparts.
Sleep in. Getting even one extra hour of sleep a week can counteract most energy-robbing sleep deficits.
Go out on the town. Sure it's fun, but studies show that a good social life can also help you feel more energetic.
Vary your routine. Switch things around—add intervals to your workout, try new lifts, cross-train. You'll challenge your muscles, furthering their development and giving you more energy.
Relax. Stress is energy's number one enemy. Next time you're swamped, zap the stress by closing your eyes and breathing deeply for 60 seconds.
Schedule a day off. Take a day every month to do something fun—no errands and nothing serious or work-related. The happier you are, the better you feel.
Pump some iron. Anaerobic exercise—like lifting—boosts levels of three compounds your body needs for quick bursts of activity, ranging from sprints to foreplay.
Veg out. Load your plate with veggies like tomatoes, carrots, and spinach. The brighter the vegetables' color, the more energy-revitalizing antioxidants they contain.
Chug a sports drink. The potent mix of water, sugar, and electrolytes may give you the juice you need to make it through that last set.