A couple of key points to keep in mind:

  • Caffeine consumed in large doses (more than 500 milligrams, which may be as many as 5 cups of coffee) can elicit a diuretic effect. However, regular consumption can build up your tolerance so that you don't experience those initials effects, meaning you might soon require more.
  • The nonhabituated caffeine user can still consume a moderate amount without causing a diuretic effect, but may be more at risk for some dehydration than habitual users in larger doses.

Don't get me wrong, I still think drinking adequate amounts of water and staying hydrated are important, especially for those who are physically active. Chronic dehydration can have a significant impact on performance and lead to headaches, fatigue and muscle cramps. But do we need to eliminate coffee altogether? Absolutely not!

>> Read more: Power Through Your First Trimester Without Caffeine

If you notice you're not performing as well in the gym, experiencing muscle cramps, or lacking overall energy during your workouts, you may want to cut back a little on the bean juice, or drink 2-3 more cups of water or low-calorie beverages throughout the day.

Do you have a question for Dr. Kendall? Place it in the comments section below; it might be chosen for an upcoming installment of Ask the Science Chick!

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  1. Silva, A. M., Júdice, P. B., Matias, C. N., Santos, D. A., Magalhães, J. P., St-Onge, M. P., ... & Sardinha, L. B. (2013). Total body water and its compartments are not affected by ingesting a moderate dose of caffeine in healthy young adult males. Applied Physiology, Nutrition, and Metabolism, 38(6), 626-632.
  2. Armstrong, L. E., Pumerantz, A. C., Roti, M. W., Judelson, D. A., Watson, G., Dias, J. C., ... & Kellogg, M. (2005). Fluid, electrolyte, and renal indices of hydration during 11 days of controlled caffeine consumption. International Journal of Sport Nutrition and Exercise Metabolism, 15(3), 252-265.
  3. Grandjean, A. C., Reimers, K. J., Bannick, K. E., & Haven, M. C. (2000). The effect of caffeinated, non-caffeinated, caloric and non-caloric beverages on hydration. Journal of the American College of Nutrition, 19(5), 591-600.