Eating for performance on competition day: and why it often doesn't resemble 'healthy eating'

Sometimes it’s really hard being a dietitian.

You think you’re telling someone something they’d really like to hear, like, ‘yes, lollies are one of your options in that circumstance’ or ‘this is the time to switch over to white bread’. But sometimes the good news falls on deaf ears. It can be hard to separate our ideas of ‘healthy eating’ from what is considered necessary for optimal performance.

Performance nutrition, especially in the context of endurance events (such as triathlons, marathons, ultra-endurance and long-distance cycling events), or longer-duration running based games (such as AFL) require unique approaches to nutrition. These approaches may not map what one considers a healthy way to eat long-term.

In terms of endurance events and long-duration running based games – the focus DURING the event needs to be on portable, easily-digestible (low fibre) carbohydrate sources. Here are some examples:
– sports drinks
– sports gels
– lollies
– white bread sandwiches with vegemite, honey or jam
– fruit (but not too much – because.. fibre)

What do these foods have in common? They all contain fast-digesting carbohydrate, otherwise known as… sugar! Now, before you log off thinking I’m a terrible dietitian for prescribing sugar. Let me explain further.

During competition at high-intensities, our bodies preferentially burn carbohydrate as a fuel. In fact, at high intensities our performance can be limited by the ABSENCE of carbohydrate. Yes, we can still move and function and compete if we eat a low carbohydrate diet, but we cannot compete at the same level of INTENSITY for the same DURATION.

Herein lies the crucial detail: most competitive sports require we operate at high intensities for some or all of the event (some exceptions to this include sports like archery). We may not operate at our maximum for the whole length of the event or game, but at various times throughout a race or a game, we may need to turn our gears up. Without access to adequate carbohydrate, our body will not perform at 100% (well, it will feel like 100%, but we won’t be going as quickly as we are capable of going).

In addition, our carbohydrate stores in our muscle and liver are LIMITED. The storage form of carbohydrate is called glycogen. Glycogen as a molecule is highly branched and without boring you too much, basically this means that we can’t fit a lot into our muscle – it takes up too much space. It also binds with water and takes this into the muscle with it, so this further limits how much we can store in there. Somehow science is amazing, because if as human beings we were designed so that we could store unlimited amounts of glycogen, we would all be too heavy and that would be a huge disadvantage (well, back when we were running from tigers, at least).

Ok ok ok, so our stores are limited, so whattttt?

Well, what THAT means, is that we need to eat carbohydrate during events that are of moderate to high intensity and that last longer than roughly 90 minutes, otherwise we actually RUN OUT OF CARBOHYDRATE (fuel)! Yikes. That doesn’t necessarily mean we stop moving all together (although, if you ‘hit the wall’ – another expression for running out of carbohydrate – sometimes it feels like you actually cannot go on), but it means the level of intensity at which we can operate at becomes severely compromised. No one ever won a marathon by jogging.

And what THAT means, is that we need to EAT carbohydrate during moderate to high intensity, long duration exercise, so that we can continue to operate at high intensities for longer durations of time (as opposed to the opposite – operating at a lower intensity, which wouldn’t be conducive to our best performance).

So, then it comes down to what TYPE of carbohydrate. Here enters sugar. When you need ACCESS to carbohydrate and you need access QUICKLY (i.e during a race, not when the race is over!), then it makes sense that we need the most easily absorbed form of carbohydrate. The most easily absorbed form of carbohydrate is it’s simplest form.

Imagine a marathon runner or a Tour de France rider trying to eat a bowl of oats while they run/ride.

I mean for starters it’s not practical. But ALSO, it takes time to digest and for the body to get access to the carbohydrate because it’s so fibrous!

Here enters the above mentioned list: sports drinks, sports gels, lollies, simple sandwiches. Things that are consumable while moving and things that provide the quickest available form of carbohydrate to the body. BOOM. Recipe for optimal performance.

(ps if you don’t believe me, here’s an article about the sports drink Team Sky uses, as quoted by their team sports dietitian – this is a drink that contains MORE carbohydrate per ml than the generic sports drink available on the market, click here to read).

Now, let’s be clear here. Carbohydrate amount and timing is ONE PART of a nutrition plan. Nutrition strategies before races/events, nutrition strategies post races/events and other nutrition strategies DURING exercise are also being addressed by the dietitian. And let’s not forget hydration!! It’s not ALL about carbohydrate, but it is a huge part of optimal performance in endurance type events/games.

Let me also be clear about this: the amount of carbohydrate needed is highly dependent on the individual. It is based on body size and event length/duration/intensity and how trained the athlete is.

An unfit, once-a-week AFL player doesn’t need bucketloads of carbohydrate. So please don’t send me hate mail, I’m not talking about EVERYONE here.

Obviously it’s not a dietitian’s job to force dietary advice down your throat. But next time a dietitian suggests some ‘fun’ foods on competition day, do consider that sometimes there is a distinct difference between performance nutrition strategies and general day-to-day nutrition strategies. Just remember, different goal = different strategy.