Multiple research studies have shown that chronic lack of sleep has about the same effect on cognition and coordination as a few alcoholic beverages. So what do you do when you need to concentrate but you are tired?
Many reach for a cup of coffee or a soda. Solid research shows that caffeine in doses between 30 and 300 milligrams improves attention, alertness, reaction time, and mood, especially when you are tired. (An average cup of coffee contains 80 to 100 milligrams of caffeine; soda, between 30 and 60 milligrams.)
But exercise, also well studied, works too. Even a short bout of cardiovascular exercise wakes us up, speeds mental processes, and enhances memory storage and retrieval, regardless of fitness or fatigue levels. So when it’s late afternoon, exercise a little or go for coffee?
One recent, but very small study, compared these two wake-up methods using healthy but chronically sleep-deprived volunteers to compare three interventions: caffeine, stair-climbing, and placebo. They found that just 10 minutes of stair-climbing boosted levels of energy far more than a moderate dose of caffeine (50 mg). However, this was a very small study. Only 18 out of 90 healthy, college-aged women met all the criteria and were willing to participate.
However, exercise offers more long-term benefits. Another study looked at the effects of either exercise alone or exercise plus caffeine on cognitive tasks. Indisputably, exercise plus caffeine had the greater benefit.
Caffeine (in the form of coffee) has been well-studied and regular intake is associated with lower risk of type 2 diabetes, high blood pressure, and obesity. The downside: it may increase cholesterol. It may also protect against certain types of dementia and cancer, although it has been associated with bone loss and rheumatoid arthritis. Basically, there are many benefits but with some risks as well.
Multiple studies suggest that exercise has multiple long-lasting positive effects on physical fitness and function, cognition, mood, and behavior in just about all populations studied, including all ages, fitness levels, and regardless of baseline cognitive function. Some of the greatest benefits were seen in older patients as well as patients at risk for or diagnosed with dementia.
The take-home message? Caffeine can provide a boost in alertness and energy levels that may help you to think faster and better, for a while. But even a short burst of exercise can do the same, maybe more, and be longer lasting. In addition, while caffeine is associated with both good and bad health outcomes, exercise is good for everything.
From Harvard Medical School