More energy on less sleep!

Shut-eye is the ultimate energizer, if you can get enough of it. For the 99.9 percent of us who can't; we have five instant uppers.

1. Skip the venti latte
You might be tempted to suck down the biggest coffee ever when you’re tired, but if you need lasting energy, sip a little at a time throughout your day. Harvard research found that small, frequent doses of caffeine helped people stay awake for 28 hours.

2. Sniff something lemony
Splurge on that citrus hand cream: A new study found that whiffs of lemon made women feel peppier. “The scent increases production of norepinephrine, a hormone associated with energy,” says lead study author Janice Kiecolt-Glaser, Ph.D.

3. Eat some good carbs
The fiber in whole grains like brown rice and whole-wheat bread provides a long-lasting source of energy for your brain and muscles, says metabolism researcher William Evans, Ph.D. Simple carbs like sweets will give you a quick rush but leave you tired later.

4. Spend five minutes with some funny online videos
It might not seem terribly productive, but laughing at a guy flying off a speeding treadmill will perk you up temporarily. Research shows that a hearty chuckle revs up the respiratory system, oxygenating the body and making you feel awake.

5. Get moving
A low-intensity workout like a short bike ride can boost energy levels by 20 percent, researchers at the University of Georgia in Athens found. Regular exercise also improves sleep—so when you do hit the sack, you sleep more soundly and wake more rested.

—Lisa Freedman