Which diet for which Athlete?

I’ve been working as a Naturopath for over 25 years. In that time, I’ve seen in practice the following philosophies: 



  1. No two bodies are the same. 
  2. No two sports have the same demands on the body.
  3. No two bodies doing the same sport have the same exact needs and demands.

Essentially this can be summed up in what I often call the art and science of Sports Nutrition. Yes, we have evidence-based research about the physiology of the body and the impact of food and nutrition on performance, BUT as a Naturopath I see each body as wholistic and individual. This means that whilst on paper something should work, I may need to work with a client to tweak a protocol to get it just right for their body and performance. Therefore, it’s so important to understand the physiological needs of the sport you undertake, role of nutrition and food specific to your sport, and yourself!

Different sport, different diet?

So, how do we know what type of diet may be better for one sport over another? The first area to look at are the physiological needs of the sport. Does a 100m sprinter need the same energy needs as an Ironman? One will be finished their race in the blink of an eye, whilst the other may last anywhere between 8-16hours depending on their level. What we are looking at here are the energy systems used in the body.

To understand the foundation of a diet for an athlete, we need to understand the energy system of the body, how they produce that energy, the fuel they need and the demands of their sport. There are three energy systems our body can use; each uses a different fueling source, and this is determined by the intensity and duration of the sport or activity. To get the most out of your body for your sport, you need to understand the metabolic, or energy needs, of the sport and recovery. There are two key energy pathways, aerobic and anaerobic (which has two subcategories).

Our anaerobic energy system is the first system we use when we start exercising.  The minute the starting pistol fires, or we move into lift our 1RM we enter the Phosphocreatine energy system. As the name suggests in this system, we use phosphocreatine and ATP for our quick energy burst. This system is short lasting (8-10secs!) and is used in our explosive efforts of high intensity exercise!  Once you’ve done your sprint, or successfully nailed your Clean and Jerk, your body recovers quite quickly back to normal operating.

But my sport lasts longer than 10secs!

What happens next is your body switches into the second anaerobic energy system, the glycolytic system. This system uses stored energy from muscle glycogen and blood glucose to fuel you for the next 10-180 seconds. This system is for high intensity exercise at 60-95% of your max efforts. This is your HIIT or AMRAP style exercises. Even though this system has a lower energy output, it takes longer the first system to replenish itself.

Sounds great, but I run for hours! What about me?

If your sport is long and continuous, think longer distance running, cycling, hiking, long distance swimming, then you slip into the aerobic energy system. You’ll still pass through the anaerobic systems, but then your body reaches steady state. This system, also called the oxidative system, relies on the metabolism of carbohydrate (CHO) and lipids to provide most of the energy required for muscle contraction. The amount of CHO or lipids used by the body in this system depends on factors like; exercise intensity, the diet prior to exercise, substrate availability, and your overall fitness level.

You’re more than just your sport!

As I mentioned in the beginning, understanding the needs of your sport is just half of the picture; the other half is you! Other factors that may increase your energy demands, and therefore your diet include: training intensity and volume, your environment (extreme temperatures or altitude can influence your energy needs), injuries, and your body mass (do you have more to burn?). There are also factors that may decrease how much fuel you need such as your age, your size/body composition, and a decrease in training.  Volume of training can vary drastically depending on if you in off season, conditioning phase, or comp periods. Training volume can even vary daily, factoring rest days, type of training (strength + conditioning, cardio), duration, and how many sessions in the day.

So, it’s important to think about not just what your sport needs you to do on comp day/race day, but also what it needs to get you there at your best. 

Not sure where to start with your fueling needs?

If you’re ready to really look at how to tweak your fuel for your sport, here are some great tips as well as some questions to be asking yourself:



  • Am I getting enough protein at each meal and snack for my training volume?
  • Am I eating in the right ratios of carbs to protein post training, and not just favoring one fuel source or being ‘carb phobic’?
  • Do I eat within the 30-45 minute of training?
  • Am I getting in enough carbs? Both after training, and in general.
  • Does my water intake match my training load, sport needs, and climate?
  • Am I craving any specific foods?  Are these cravings indicative of a nutrient I’m lacking?
  • Am I craving carbs/sweets? When? Am I using these as a quick hit because I haven’t fueled properly post training?
  • Has my training changed, but my fuel stayed the same? Do I need to reassess what I’m doing, how much, and when?
  • Is my fueling based on habit and routine, as opposed to following the dynamics of my life and training?

Where to next?

Hopefully you’ve gained a little bit of insight into why you may need a different diet for a different sports, and also why you may need a different diet to your race mate who trains just as hard as you. There are so many factors to consider when it comes to fueling your body, and a sport’s physiological demands are just the tip of the iceberg. If you want to dive a bit deeper, why not check out my course for Fueling for Fitness. This is a great toolkit for athletes (which by the way is anyone training consistently, not necessarily professionals) to start to get a better handle on how to make their bodies reach their potential.  If you want to work in private consultation with me you can connect here.