Coffee - can it help or hinder your workouts?

What’s the bet that you woke up this morning and started your day with a coffee, whether it be at your favourite café or snuggled in bed with your trusty home brewed Nespresso. This is because many of us, including me, have developed a reliance on the beautiful effects which caffeinated coffee can bring to our day. While coffee might be the first thing that comes to mind when I mention caffeine, there are a wide variety of caffeinated products which can assist not only your mornings, but also your exercise performance.

What is caffeine?

Caffeine is a natural stimulant which is found in the leaves, nuts and seeds of many plants. We consume caffeine through coffee, tea, energy drinks, supplements (pre-workout in particular) and caffeinated sports drinks or soft drinks. It is well known for helping us to be a better version of ourselves, especially when we are stressed or sleep deprived. This is because caffeine is known to improve mood, concentration and performance through a range of chemical and physiological pathways. The caffeine content of some common foods and sports foods/supplements is listed below:

Caffeine Product Serving Size Caffeine content*
Café coffee 250mL cup 80mg
Black tea 250mL cup 27mg
Chocolate 60g 5-15mg
Coca Cola 375mL can 36mg
Red Bull 250mL 80mg
Endura Sports Gel 35g 8.5mg
Clif Bar 68g 50mg


*Please note that these are estimates and may vary depending on specific brands or production processes. For specific caffeine content, refer to the nutrition information panel on your specific product.


So, can caffeine affect my sports performance?

Yes! Many athletes utilise caffeine to assist their sports performance. The main benefits have been associated with caffeine’s impact on the central nervous system and its ability to reduce the perceived perception of effort and fatigue. This means that when consuming caffeine, athletes can train harder and faster for longer. Research indicates that doses of caffeine of approximately 2-3mg/kg (e.g. approx. 140-210mg for a 70kg adult) have demonstrated efficacy in improving performance outcomes.

Caffeine is also listed in the Group A ranking in the Australian Institute of Sport’s Supplement Framework. This means that it has strong scientific evidence backing it’s use in specific sporting populations and is permitted for safe use by athletes when following best practice protocols.

How do I know if caffeine consumption is right for me?

It is best to discuss any supplementation regimes or changes to your training diet with your dietitian, to develop a personalised and safe plan suitable to your specific situation. However, there is strong evidence that caffeine intake will likely enhance performance in the following sports:

  • Endurance sports (longer than 60 minutes)
  • High intensity intermittent training
  • Sports requiring single efforts of strength and power
  • Sports requiring maintained concentration

Other extra perks of coffee consumption

I did warn you that there might be a slight bias towards coffee! That is because research has indicated that the antioxidants provided by moderate tea and coffee consumption (approx. 3 cups per day) may be protective against cardiovascular disease, Type II diabetes and certain chronic inflammatory diseases. So just in case you needed an excuse for a coffee date… having a cuppa might not only help you train harder, but it might also be protective against some lifestyle related diseases in the long run too.

So, what’s the catch?

While there are many benefits to caffeine, it is important to consider that caffeine affects everyone differently and that it can affect the following aspects of your life, which may influence your training. Some things to consider include:

Sleep: Quality sleep is crucial for optimal recovery and training quality, so it is important to time your caffeine intake carefully to ensure that you achieve the best of both worlds. It is important to limit your caffeine intake late in the day, to allow your body enough time to remove it from your system, so that it doesn’t negatively impact your sleep quality.

Dehydration: Hydration status is a fundamental component of maximising training. Caffeine can have a mild diuretic effect in some people, which raises the question about its impact on your overall fluid status. However, evidence suggests that moderate doses of caffeine do not increase the risk of dehydration and that when consumed in a liquid form, such as coffee or tea, it can contribute as a source of hydration.

Gut issues: We’ve all either heard of coffee tummy, or experienced it personally. When we exercise, we stimulate the muscles surrounding our intestines, which is important for promoting healthy bowel movements. However, when this is paired with caffeine, which is also a gastric stimulant, it can contribute to uncomfortable and urgent bowel movements. Therefore, it is important to trial integrating caffeine into your training diet, to develop an understanding of how caffeine impacts your body, so that it doesn’t interfere with your performance on game-day.

Now that you have the scoop on all things caffeine, you can make the decision regarding whether it is something you want to integrate into your training regime. As always, consult your dietitian if you have any specific medical conditions which may be affected by caffeine consumption, or if you would like to develop an individualised dosing strategy for your lifestyle and training.

Annalie Houston

Accredited Practising Dietitian/ Accredited Nutritionist