In the past, it was widely believed that caffeine was a diuretic that contributed to dehydration. More recent research has revealed that coffee, tea, and other caffeinated beverages do not negatively affect the level of hydration of those who are accustomed to consuming caffeine, and it only has a diuretic effect if consumed in large amounts (i.e. 500-600 mg/day). In other words, trying caffeine for the first time or chugging a huge caffeinated drink before a run might not be the best idea if you are trying to avoid issues. Instead, runners should slowly integrate caffeine into their diet to see how their body reacts to it. Otherwise, if you are a regular coffee drinker, then enjoy your favorite caffeinated beverage while continuing to focus on maintaining proper hydration with other fluids.

Early researchers thought caffeine's benefit on sports performance was linked to the substance's ability to spare muscle glycogen and increase fatty acid metabolism. The current consensus suggests otherwise, showing that the positive effects of caffeine are more strongly correlated to mental sharpness. Studies on sports performance have found that caffeine produced a 24% improvement in endurance performance and a 4% improvement in strength performance. The quantity of caffeine that promoted the biggest gain in performance was 6 mg/kg of body weight, while having less than 3 mg/kg resulted in a minimal performance gain or no improvement whatsoever. It's important to be aware that the amount of caffeine needed for increased sports performance can depend on an individual's sensitivity to the substance. Coffee and tea can also interfere with iron absorption, so those who suffer from anemia should be mindful of their caffeine consumption, especially when preparing for a run.

Caffeine not only affects sports performance but our entire bodies as well. Bone health is a topic that is frequently associated with the effects of caffeine, but luckily, research has found that caffeine is not a significant contributor to poor bone health. That said, this is only true when adequate amounts of calcium are also being consumed. This is why it is important to eat at least two servings of calcium-rich foods daily to keep your bones healthy and ready to run.

Cancer is another health concern that is frequently intertwined with the effects of caffeine, and rightfully one that has caused a lot of concern. Fortunately, the American Institute for Cancer Research (AICR) recently released findings that showed that coffee was no longer a substance associated with an increased risk of cancer. In fact, because coffee contains antioxidants and has anti-inflammatory properties, it may actually reduce the risk of cancer. So don't worry the next time you sit down with your favorite morning brew.

Finally, we have come to the heart. Many worry that caffeine, as a stimulant, can negatively affect our heart's health, contributing to conditions like heart disease. Once again, recent research shows that there is little relation between caffeine ingestion and heart disease. There may be exceptions, as caffeine affects each individual differently, so check with your physician if you are experiencing elevated blood pressure or arrhythmias.

Caffeine can be worked into any athlete's meal plan to boost athletic gains, but only as long as it is done mindfully: paying attention to overall daily hydration, consuming the recommended daily amounts of calcium, and following an overall well-balanced diet. Runners must also keep in mind that caffeine consumption is not recommended for everyone, so a conversation with your physician is advised if you are thinking about incorporating or increasing the amount of caffeine in your nutrition plan.

Read our other articles on the Running Warehouse Europe Learning Center.