A little caffeine hit can be a great way to get your mind and body going, but too much of anything can be detrimental for performance and health.
Our Move With Us dietitians break down the benefits and side effects of caffeine, and answer the number one question - just how much of the energising substance is too much?
How much is too much?
Although caffeine sensitivity can vary per person, for most healthy adults up to 400 mg caffeine per day is the sweet spot. If you’re pregnant or breastfeeding, slash this allowance by half - and for certain population groups, such as children, it’s best to minimise any caffeine intake.
As a reference, this is what 400 mg per day may look like**:
- 4 brewed coffees;
- or 4 espresso shots (remember - “medium” and “large” coffee shop beverages often contain 2+ shots per serve);
- or 2 “energy shot” drinks
**these estimates are all approximate - caffeine content may differ considerably between brands
Something that also gets overlooked is that caffeine isn't just found in coffee and is contained in many common foods and beverages, meaning you need to be aware of all caffeine sources in your diet. For example, it’s naturally present in tea and chocolate. Caffeine is also often added to lollies, sports drinks, energy bars and more - so it always pays off to have a look at the packaging to ensure you’re staying within the safe limit.
Benefits of caffeine
Caffeine is a natural stimulant that primarily works by blocking your brain's adenosine receptors, which play a role in sleep, alertness and cognition. Because of these effects, when consumed in moderation, caffeine can offer great perks, such as:
Athletic performance boost
Caffeine is the main (and often the only) active ingredient in a variety of popular pre-workout supplements, and it’s definitely not for nothing!
There’s lots of research backing up caffeine’s ability to boost various aspects of athletic performance when consumed before a training session - such as muscle and aerobic endurance, muscle strength, and anaerobic power.
Importantly, these effects can be attained at as little as 1.5-3 mg/kg body weight - translating to ~200mg for most individuals. So, more is not better - and going overboard can have opposite effects!
Even when consumed in small to moderate amounts (0.5-4 mg/kg body weight), caffeine can produce the effects of alertness and focus. So if you swear by your morning cuppa to start the day, this may be why!
However, caffeine alone is not enough for optimal functioning unless paired with adequate sleep hours - 7-9 per night for most adults.
Brain power (but there’s a catch)
Caffeine can be just the temporary pick-me-up you need to increase various aspects of cognitive functioning and get you through the day - win, right?
Well, the catch is that the most prominent effects appear to be observed if you’re sleep deprived, and still won’t restore your brain power to 100%. On the contrary, if you’re on top of your zzz’s, the boost may not be impressive enough to load up on caffeine solely to boost that brain power.
In addition to the above, there are also studies pointing to other potential benefits of moderate caffeine consumption, but don’t rush to incorporate caffeine into your diet just because of these, as more research is required to draw definitive conclusions.
What happens if you overdo it?
As a natural stimulant, caffeine can cause undesirable side effects if consumed excessively (either beyond the guidelines above or exceeding your individual sensitivity), such as:
- Increased heart rate
- Stomach discomfort
- Poor sleep
Granted, these are typically not lasting or life-threatening, and it’s hard to reach dangerous levels of consumption from everyday foods and beverages. However, it’s important to monitor how much caffeine you are having, and how much is too much for yourself.
Do you need a “caffeine detox”?
You probably know people who can drink a cup of coffee with their midnight snack and fall back asleep soundly; as well as those who start bouncing off the walls after just one sip.
These differences don’t just come down to both one’s individual caffeine sensitivity - turns out we can develop caffeine tolerance over time! Remember the adenosine receptors we’ve mentioned above? Research shows that in regular caffeine consumers, their overall number may increase over time, meaning less striking caffeine effects.
As consuming more caffeine is only safe up to a certain limit, if you’re longing for a stronger pick-me-up effect, you may want to opt for a “caffeine detox” to reset your caffeine tolerance.
There are 2 safe, simple ways to achieve this:
- By decreasing your daily caffeine intake (for example, if you are used to 3 cups a day - cut back to 1)
- Or consuming it less often and incorporating caffeine-free days
There are no hard-and-fast rules here, just monitor how you’re feeling and go from there.
Keep in mind: discontinuing caffeine consumption abruptly is likely to cause “caffeine withdrawal” side effects such as headaches, irritability and poor concentration - so unless medically indicated, there is no need for drastic measures.
Within the safe limits, caffeine can be incorporated into a healthy, varied diet and even bring some much welcome benefits along - so for most people, there is no need to cut it out.
However, remember that caffeine is no substitute for a balanced lifestyle, meaning plenty of sleep every night, regular physical activity and balanced nutrition. Instead, it’s just a little something that can work in your favour by following the tips above!