Before you reach for that 8 am coffee, hold up. While most of us instinctively crave a jolt of caffeine the moment we wake up, science says it's best to wait an hour or two.
Think about it: our bodies work around our circadian clock -- a 24-hour hormonal cycle that tells you when to wake up, when you're hungry and when to sleep. Production of cortisol -- a hormone that makes you feel alert -- peaks between 8 am to 9 am, the time most of us reach for the first latte of the day. However, since the cortisol is already naturally caffeinating your body, the effect of the coffee will be diminished.
Even worse, by drinking coffee when it's not needed, your body will build a faster tolerance to caffeine. As a result, it will increasingly take more and more coffee to achieve that boost in the future. Above, the simple graphic from I Love Coffee shows you when your cortisol levels peak and when they drop. Conclusion: Mid-morning and early afternoons make for optimal coffee breaks.