Nutrition for Sports Performance Part 2: What to eat during training

You’re halfway through your training session and are starting to feel light headed, fatigued and its getting difficult to move your muscles. You’re considering calling it in early because you’ve got training on again tomorrow morning and need to be ready.

This is a common scenario amongst my clients and I have definitely felt it myself too! Nutrition during training has been found to prolong the time it takes for fatigue to set in meaning that you can work harder for longer. It also improves recovery so that you are fresh for your next session.

So what should you eat during your sessions?


You need to stay hydrated. Your blood carries oxygen and nutrients to your brain and working muscles. Dehydration causes your blood to thicken and deprive your muscles of the nutrients it needs to perform or train hard.

Water is generally all you need. In some cases, on hot days and during long training sessions, sports drinks or electrolyte drinks can be helpful.

Gatorade and other sports drinks give good energy and nutrition when competing

Sports drinks and coconut water

Sports drinks provide some added electrolytes to aid absorption but work largely on the principle that they taste good so you’ll drink more. They also contain sugars which can be a helpful way to get some carbs in during your session (more on that soon!). Similarly, coconut water contains some electrolytes but not in the specific ratios needed to make a big impact on absorption. It does, however, taste amazing so you’ll probably drink more of it.


Elegrolyte drinks (ie Hydralyte) contain a specific and calculatd amount of electrolytes to enhance water absorption through your small intestine (it’s usually only absorbed in your large intestine). These are most effective in extreme conditions, however, for the majority of the time, plain water will be adequate.


Carbs are your working muscle’s favourite source of energy. We do store carbs as glycogen in both liver and muscles. Your pretraining meal will help to top up your circulating glucose stores, however, in once your carbohydrate stores are used up, your body needs to use less efficient means of creating energy such as breaking down fats or proteins meaning that you can’t train as hard or it all just begins to hurt more!

woman competing in a triathlon

As mentioned in Part 1 on how to fuel before session, evidence supports ingestion of 30-70g of carbs per hour of training. It might be worth topping up if you are working hard for a long period of time. If you’re topping up on the go you are going to want something that is processed quickly in your gut and won’t leave you feeling sick.

Try these little ideas:


Branch Chain Amino Acids (BCAA’s) are becoming popular among athletes for their role in muscle protein synthesis and recovery. Your body is unable to produce these amino acids (Leucine, isoleucine and valine) and so they must come from food. Unlike other amino acids they are metabolized in your skeletal muscle rather than the liver.

What do they do?

Research suggests that BCAAs have multiple roles in training and performance:

  1. Stimulating muscle protein synthesis

  2. Preventing muscle protein breakdown

  3. Reduce markers of muscle cell damage post exercise

  4. Act as an energy source during training

  5. Reduce feelings of fatigue

Healthy woman exercising

It’s still unclear whether supplementation with BCAA’s provides added benefits over food or regular protein powders, however, for someone on an energy budget, BCAA’s may provide these benefits with minimal calories.

How should they be incorporated?

For maximum results in training, choose BCAA’s a dose of BCAA’s that provides roughly 2-3g of leucine to have during your resistance training session.

You can get these portions of protein from foods. See Nutrition for Sports Performance Part 3 for protein foods and amounts containing this Leucine portion.


You can alter your body’s response to training by providing adequate fuels and building blocks in the form of carbohydrate and BCAA’s. Dose and necessity will depend on the individual, the mode of training, intensity and training goals. It is best to talk to an accredited dietitian for individualised advice.