How Much Caffeine Is Too Much?

How Much Caffeine Is Too Much?

Most of us enjoy a cup of tea or coffee, and in moderation caffeine does have some proven benefits. However in large doses, it can have lots of negative affects.

I’ve taken a good look at the amount of caffeine in things we eat and drink and looked into how much might be too much to have everyday.

The Benefits

Step Aside Monday coffeeIn moderation caffeine can:

  • Boost our mood,
  • Increase our energy,
  • It can improve our memory,
  • Help keep you alert,
  • Increase stamina and effort level during exercise,
  • Can act as an appetite suppressant


Personally I’ve experienced all of these, there are other claimed benefits but the studies are weak at best and I personally haven’t noticed them, so can’t/shouldn’t really comment.

I love coffee, not for the taste but for the stimulant effect. I only started drinking coffee in 2009 and as a result am very susceptible to its effects. Up until 2009 I only ever got caffeine through fizzy drinks or chocolate.

The Negative Effects

These negative effects are typically only an issue if caffeine is consumed in large doses, the person is very susceptible to caffeine’s affects or if caffeine is consumed in large amounts under extreme or prolonged exercising conditions.

High amounts of caffeine can:

  • Cause dehydration, as it is a diuretic, caffeine can flush water and also essential minerals from the body. Causing cramps and loss of concentration or headaches.
  • Can affect sleep. Making it harder to fall asleep or to wake up during the night.
  • Can cause heart palpitations
  • Can increase anxiety and/or worsen depression symptoms
  • Can increase blood pressure, especially in those who already suffer from high BP
  • Can cause diarrhea, indigestion or other digestion issues
  • Can make you more aggressive or impatient
  • Is addictive and leads to cravings & withdrawal symptoms


How Much Is Too Much?

Too much coffeeI’ve a friend who can drink 7/8 cups of instant coffee a day, even right before bed and show none of the above effects (that I know of). However, he doesn’t exercise, so would be confident that if he did, he’d suffer badly from dehydration. A relative drinks 10 cups of tea a day and shows several of the above negative affects. Could be coincidence or may be exacerbated by their high caffeine intake?

Caffeine like any drug affects people differently. You can build up a tolerance to it, crave it and withdraw from it. I believe, it’s only when the negative effects, damage your sleep, increase your day to day stress levels, worsen your health or affect your sporting performance, that it should become a concern. If you find yourself noticing several of the negative effects listed above, then perhaps you should cut down your intake?


My Own Addiction

Coffee Spoon FunnyI crave coffee. Typically 2-3 days a week I get up at 5am and work until 9.30pm. I’ll have an instant coffee (80mg approx) in the morning. At 2pm, I’ll get a medium Americano shop bought coffee but ask for just 1 shot (120mg approx). Then, at 5pm, I’ll have a 2nd medium Americano, with 1 shot (120mg). So on my busiest days the total caffeine I consume is normally 320mg.


This I consider high caffeine for me, as I find it can dehydrate me when exercising, or that night I’ll suffer from slight to bad cramping. On other days I’m not working as many hours, I try to have just 2x 1 shot Americano’s and this is enough to stimulate but not dehydrate me.


Caffeine Contents Of Common Drinks.

Amounts vary substantially between brands and all the below info is approximate, based on online research.

  • Instant coffee 1 heaped spoon = 65mg-95mg depending on brand
  • Café/Restaurant coffees, each shot contains = 95mg-140mg depending on brand. Bare in mind even some small coffees contain 2 shots. Ask your barista. Large or Venti can have 3, 4 or 5 shots of coffee in them.
  • Nespresso type shots = 55mg-90mg depending on blend
  • Brewed Coffee, 1 mug = 120-170mg depending on strength and brand
  • Cup of Tea = 40-60mg
  • Green Tea = 40-50mg
  • Can of Diet Coke or Coke = 35-40mg approx
  • Energy Drink = 80mg per small can/bottle, large cans will have a lot more
  • Regular bar of chocolate = 35-50mg
  • Decaf Café/Restaurant coffee, contains approx 20-4mg of caffeine per shot
  • Chocolate or Coffee flavoured ice-cream – 30-50mg of caffeine per half cup
  • Diet pills (I do not recommend anyone goes near these – ever). Anything from 300mg-1100mg of caffeine!
  • Cold & Flu drinks & capsules 25-50mg caffeine

Now try to approximate how much caffeine you’re consuming each day and if you notice any negative effects from it?

Ways to easily cut down.

  • Ask for decaf, not every time but if you only have a craving and don’t need the extra energy maybe a decaf will do? It still has caffeine but a lot less.
  • Ask for 1 shot when buying from Cafes/Restaurants
  • Have less shop bought coffees, switch to instant instead and save money and on the amount of caffeine.
  • Switch to tea instead of some of the coffees, if you drink a lot.
  • Avoid caffeine after 6pm
  • Cut back gradually or have 1 day a week caffeine free. You then also get a higher affect from it the next day, so require less (in theory)

Caffeine & Exercise

Personally I sweat a lot and if on a long cycle or teaching lots of classes back to back, to prevent cramping and big dips in my energy levels, I avoid caffeine beforehand and only use it when I need it – in the last half of a cycle. But if training for 90mins or less, I will have a coffee beforehand as its a great stimulant.

In my experience the first common sign of dehdration while exercising is, cramps in the calf muscles, it can then spread to the quad and if severe to the upperbody. Concentration and ability to make decisions can be affected. For example, taking a wrong turn out cycling, losing count of laps left in a race, forgetting to eat on a long event, losing concentration on a turn and sliding on gravel or swerving in a group of cyclists.

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author: Andy Kenny