There are 4 key components involved in optimising nutrition during high-intensity training and competition.
They are:
Provide sufficient glucose.
Provide sufficient amino acids.
Provide sufficient fluids and electrolytes.
Do the above whilst minimising digestive upset.
1. Provide sufficient glucose
If you’ve read previous articles, you’ll know by now the importance of carbohydrates when it comes to fuelling high-intensity exercise.
That is, carbohydrates are broken down into glucose, which circulates in the bloodstream to be used to create energy for the body, or to be stored as glycogen for energy at a later time-point.
When it comes to the period of time during training sessions and competition, a lot of the fuelling work will have been done in the days and hours leading up to that point.
So whilst you won’t need to rely on the intra-performance period alone for your fuelling, it is an extra opportunity to replenish some of the carbohydrates that you will be using during the training session or competitive event.
As you can imagine, the importance of replacing the carbohydrates used in that event will increase as the intensity and duration of the event increases.
As an example, someone who is running a marathon, which could take 3-5 hours of consistent output, will benefit more from consuming carbohydrates during that run - and will require more carbohydrates) than a GAA player playing for 60-70 minutes will (even though the GAA player is still likely to benefit).
Athletes engaging in endurance events lasting over 70 minutes can maintain glycogen levels by consuming about 30 grams of carbohydrates every 15 minutes.
However, there is research suggesting that most people can only digest about 1g of carbohydrate per minute (i.e. 60g per hour), particularly during sporting events, where digestive function may be decreased due to less blood flow to the gut.
This can be increased by “training the gut”, through exposing it to higher doses of intra-training carbohydrates over time, and by optimising the sources of those carbohydrates.
For example, combining glucose-based carbohydrate sources with fructose-based sources can increase the digestibility of the overall mixture.
This may be less applicable to field sports, for example, due to the shorter duration.
A GAA, soccer, or rugby player, for example, might benefit from consuming 20-30g of carbohydrate during the warm-up and 20-30g at half-time, with the option of having another 20-30g should the match go to extra time.
A distance runner on the other hand, might aim to consume 30g of carbohydrates every 30 minutes for the duration of the event.
These carbohydrates can come in many forms including sports drink, energy gels, jelly sweets, and carbohydrate powders, each of which have their advantages and disadvantages.
2. Provide sufficient amino acids
Protein is generally seen through the lens of recovery and muscle building, and for good reason.
The amino acids supplied through protein can be seen as the building blocks of muscle tissue, and sufficient intakes of protein allows for the creation of new muscle tissue and the reduction in breakdown of existing muscle tissue.
Amino acids are less well-known for their other functions, such as their role in glycogen replenishment, hydration, and in the creation of neurotransmitters such as dopamine, serotonin, and norepinephrine, which are crucially important when it comes to the psychological component of athletic performance.
When it comes to the intra-performance period, in most cases, providing extra aminos acids (or protein) during the event itself is not necessary.
However, as with carbohydrates, increasing the intensity and duration of the event increases the potential need for intra-performance supplementation of protein or amino acids.
That is to say, if you’re not training hard and/or long, there’s no need to even consider intra-performance protein intake.
Additionally, the length of time between the previous protein feeding and the event is important to take into account.
If the previous protein feeding was within an hour or two leading up to the event, it is likely that there will be sufficient amino acids still available during the training session or competitive event.
However, if there is a long delay between the previous protein feeding and the event (e.g. If you’re training first thing in the morning without having had breakfast, or if your schedule meant you weren’t able to eat close to the event), consuming some form of protein or aminos acids intra-performance becomes more beneficial.
If you deem it potentially beneficial to consume protein intra-training, 20-30g of protein in the form of whey or other protein powder is sufficient.
An EAA (essential amino acids) supplement can be used (about 5-10g) in place of a protein powder during activity if digestion of protein powder is problematic for you (which may be the case when the training is sufficiently intense and/or long).
3. Provide sufficient fluids and electrolytes
As with carbohydrates, adequate hydration in the days and hours leading up to your training session, match, or other performance event should put you in a good place.
That is to say, showing up to the event hydrated is probably more important than what you’re going to do during the event.
However, given that you are going to be using and excreting both fluids and electrolytes during the event, replacing those is going to be important when it comes to optimising performance throughout the event.
Otherwise, as internal fluid levels decrease, problems occur with temperature regulation and electrolyte levels, which can lead to issues with blood flow, muscle contractions, and increased perceived exertion.
Providing adequate levels of fluids and electrolytes during exercise can help avert those issues.
The amounts of these required will depend on the intensity of the session, the length of the session, the ambient temperature, and the individual's sweat rate.
A good starting point is around 250ml of water (with electrolytes/salt) every 15 minutes.
Some research suggests that the gut can’t process much more than about 1 litre of water per hour, so limiting your intake to below this level is recommended.
In terms of electrolytes, aiming to consume enough to provide 0.5-1g of sodium per hour (in the form of table/sea salt or an electrolyte supplement - which will also provide other necessary electrolytes) is generally close to optimal for most people.
4. Do the above whilst minimising digestive upset
All the recommendations above mean very little if you’re bending over with stomach cramps during a race or having to run off the pitch to the toilet in the middle of a GAA match.
For that reason, doing the above whilst minimising digestive upset with your intra-performance nutrition is key.
This can generally be done by addressing the quantities of each of the intra-performance ingredients, as outlined in the next section.
THE ULTIMATE HOME-MADE INTRA-PERFORMANCE DRINK
Given all the above, if you have the ability to access a drink bottle/shaker during the training session, run, match, gym session, or other performance event, you can consider making our own intra-performance drink.
Based on the above, this should consist of a carbohydrate powder (30-60g of something like cyclic-dextrin, maltodextrin, or dextrose), electrolytes (enough to provide 0.5-1g of sodium, in the form of supplement or salt), whey protein or an EAA powder (20-30g or 5-10g, if necessary), and 500-1000ml of water. If needed, you could also add a flavoured juice for taste.
In order to minimise digestive upset this drink should be a 7-10% solution, meaning that only 7-10% of the total drink should be made up of the ingredients above with the other 90%+ being made up of water.
You can start sipping on this from the start of the warm-up right through to the end of the event.
If more practical, you can drink half of it before the session, and the other half during breaks.
You could also experiment with the addition of some sugary sweets or energy gels if you need more carbohydrates, which would be of particular importance for something like a marathon, where carrying a sufficiently large bottle/shaker isn’t practical.
With these recommendations, it's important to pay attention to your body's feedback.
More specifically, how do your energy levels feel with differing amounts and timings of these? How is your digestion affected?
Finally, it's important to practice this approach in training sessions before trying them out in matches, races, or other competitive events. This will help avoid any unwanted stomach upsets or energy fluctuations when it matters most!
Article Written By Conor O’Neill
Conor O’Neill is a Nutritionist, Strength & Conditioning coach, Psychologist, and Author.
He has helped 1000+ everyday athletes to pursue excellence in their physique and performance through optimising their nutrition, training, and psychology.
You can find out more about The Everyday Athlete Program by going to everydayathleteprogram.com/coaching.