Caffeine: 14 Common Questions & Misconceptions

Question: Does caffeine dehydrate you at rest?

Answer: When you regularly drink caffeine and have about 250-300 mg per day (around 3 cups of coffee), it won't make you dehydrated. But, if you have more than 500 mg of caffeine (about 5 cups of coffee), it might make you pee more.

Question: Does caffeine dehydrate you during exercise?

Answer: When you exercise, things like how much you sweat, how much water you drink, and your genes affect your hydration more than a normal amount of caffeine.

Question: Does caffeine decrease body weight and fat mass?

Answer: Right now, there isn't enough clear evidence to say that caffeine helps you lose weight or burn fat.

Question: Does habitual caffeine consumption influence the performance response to acute caffeine supplementation? 

Answer: Most studies show that if you regularly drink caffeine, it won't negatively affect your performance when you take caffeine before exercising. But we need more research to be sure.

Question: Does caffeine affect upper vs. lower body performance/strength differently?

Answer: How caffeine affects your upper and lower body strength depends on the amount you take, your individual differences, the size of the muscle group, and the type of activity you're doing. It's not just about whether it's your upper or lower body.

Question: Is there a relationship between caffeine and depression? 

Answer: A normal amount of caffeine might help some people feel better, but too much caffeine can make anxiety worse, mess with your sleep, and negatively affect your mental health, especially if you have depression.

Question: Can too much caffeine kill you?

Answer: It's very rare, but if you have more than 5 grams of caffeine (around 50 cups of coffee), it could be deadly.

Question: Are there sex differences regarding caffeine's effects?

Answer: Studies on how caffeine affects males and females differently have mixed results, but caffeine seems to help both sexes perform better in sports.

Question: Does caffeine work for everyone?

Answer: People respond to caffeine differently, but it's probably rare for someone to not have any performance improvement from caffeine.

Question: Does caffeine cause heart problems?

Answer: How caffeine affects your heart health depends on how much you have, how long you've been having it, how you consume it (like coffee or tea), and your individual metabolism and genes. The FDA suggests having no more than 400 mg of caffeine per day (about 4 cups of coffee).

Question: Does caffeine promote the loss of bone mineral content?

Answer: Some evidence shows that having 4 or fewer cups of coffee per day (400 mg of caffeine or less) is the limit for possible concerns about bone density and fracture risk, especially in women. But more research is needed.

Question: Should pregnant women avoid caffeine?

Answer: Most studies show that when pregnant women have caffeine, it can lead to problems with the pregnancy. Pregnant women should have very little caffeine or none at all.

Question: Is caffeine addictive?

Answer: Even though you can have withdrawal symptoms from caffeine and some people might have trouble controlling their use, current evidence doesn't fully support calling caffeine addictive like other drugs.

Question: Does waiting 1.5-2.0 hours after waking to consume caffeine help you avoid the afternoon "crash?

Answer: There's no evidence that waiting to have caffeine 1.5-2 hours after waking up prevents an afternoon "crash" or changes your body's normal daily rhythm of the hormone cortisol.