My HormonologyNotice that on some days shortly after waking up you feel more alert and ready to take on the world than on other days? That’s the work of the “cortisol awakening response“–a naturally-occurring spike in the stress hormone cortisol about 30 minutes after you wake up that helps get your brain and body energized and prepared for the day ahead. Research shows that certain factors affect how much this energizing hormone surges in the morning, for instance, it’s greater when you wake up earlier rather later, you sleep through a night when there’s total quiet, you don’t take aspirin before turning in, and it’s a workday as opposed to a day off.

Now a study in the journal Psychoneuroendocrinology reveals you’re also likely to experience a bigger surge in energizing cortisol in the morning during your ovulation phase, which is the last two days of Week 2 of your cycle and the first day of Week 3 (Days 13, 14 and 15 in a 28-day cycle). Credit goes to high estrogen on these days, which prompts a higher production of this pep-boosting hormone.

So, how can you use this to your advantage? If you’ve got an important activity to plan that occurs early in the day and requires a lot of mental or physical energy (like a breakfast meeting or moving), consider having it fall on one of these ovulation days since you’ll have more get-up-and-go right from the start. And if you can’t schedule it to fall during your ovulation phase, then keep in mind the other factors mentioned above that affect morning cortisol levels to ensure you wake up with lots of oomph!