Until someone invents a healthy (and legal!) pep pill, here’s the next best thing: simple, proven tactics that keep you powered up morning, afternoon, and night.

Savor the Sunshine

Sunlight is an effective natural signal that has the ability to change the circadian rhythms from tired to active. The light that you can feel at dawn before sunrise can rouse special cells located in your eyes then send a signal to the internal clock of your brain. The eyes are very sensitive to this optical wake-up call when the pupils are still dilated from sleep, according to the researchers from the Center for Light Treatment and Biological Rhythms at Columbia University Medical Center. So, it’s vital to acquire what you can early in the morning.

Exposure to sunshine anytime of the day can help boost alertness. According to a Japanese study, about 16 women have reported they were more alert after being exposed for 30 minutes near a sunny window as compared to sitting in a lab that is dimly lit. The energy increase lasted for about an hour.