Triathlon Nutrition Priorities: What to Fix First

Triathlon nutrition priorities work in a fixed order, and most triathletes run that order backwards. The eight things worth fixing, in sequence, are your overall energy intake, your carbohydrate periodisation, your protein distribution and your day-to-day food quality first, then your hydration and electrolytes, your key micronutrients, your race nutrition strategy and finally performance supplements. Start at number eight and you can spend a fortune on sports nutrition products and still have race day fall apart in the back half. 

I covered the first four in Episode 229. This post picks up at number five.

Why the Order Matters More Than the Individual Fix

I have had athletes come to me having spent thousands on supplements while the foundations underneath were still a mess. One brought me a hydration patch. One asked about organic beef spleen. One had a protein shot with 60g of sugar in it, which is roughly a can and a half of soft drink, taken in the name of recovery.

None of these people are silly. They are smart, capable athletes training 15 hours a week around a full-time job, and they have been sold the idea that the next product is the missing piece.

Think of it as a cake. Your foundations are the sponge. Your sports nutrition is the icing. Supplements are the sprinkles on top of the icing. Sprinkles are lovely. They are also completely pointless on a cake you have not baked yet.

Why Is Hydration Number Five and Not Number One?

Because hydration is the one nearly every triathlete is certain they have sorted, and almost nobody actually does.

Both directions go wrong. Some athletes turn up chronically underdone. Others massively overdo it. I worked with an athlete preparing for a full distance race who was drinking a 750mL bottle an hour on the bike and stopping for a wee five times in three hours. Every one of those stops is time you have paid for in training and are now handing back.

Here is what most people get wrong about sweat testing. A single test gives you a snapshot, not a number you own for life. Sweat rate and sweat sodium concentration vary considerably both between athletes and within the same athlete, shifting with exercise intensity, environmental conditions, heat acclimation, body size, diet and hydration status (Baker, 2017, Sports Medicine ). A test you did in a Brisbane winter tells you very little about what your body will do in Cairns in June.

If you have had one sweat test and treated the result as permanent, then you are working off a number that has already moved.  

Which Micronutrients Actually Matter for Triathletes?

Three of them, and they are the ones that quietly put a ceiling on everything else: iron, calcium and vitamin D.

Iron's most important job for an endurance athlete is transporting oxygen to the working muscles. Iron deficiency is common in athlete populations, particularly in females and in endurance athletes specifically, and the association between iron regulation and sport performance is well established (Sim et al., 2019, European Journal of Applied Physiology ). What that means in practice is that you can be genuinely fit, training across three disciplines every week, eating what looks like an excellent diet, and still not be absorbing enough.

One athlete came to me having an iron infusion every three months and napping every single day. She had decided that fatigue was just part of being an active person. Nobody had gone looking for the cause, so she was being band-aided four times a year, indefinitely. She has not needed an infusion since we found the actual problem. She also stopped needing the nap, and she qualified for worlds.

Calcium is different, because your bones work like a bank account. When there is not enough calcium coming in from food, your body makes a withdrawal to keep blood calcium stable. Nobody sends you a statement. The withdrawals happen quietly for years and most people find out when something breaks, or when a routine bone mineral density scan comes back osteopenic (bone density lower than it should be, though not yet osteoporosis).

I worked with an athlete whose coach told her to cut dairy, because dairy causes inflammation. She did as she was asked, while going through a significant hormonal shift and training 15 hours a week for a full distance race. A few months later she had a stress fracture and a T score of minus 2. She showed her coach. He told her it was still fine. He is not her coach any more (thankfully). Two years of proper guidance later, her bone density has improved substantially.

Low energy availability is the underlying driver in a lot of these cases, and impaired bone health is one of its recognised consequences (Mountjoy et al., 2023, British Journal of Sports Medicine ).

If you are about to buy three supplements at the chemist on the strength of this section, then stop.  Get tested first. Athletes need different reference targets than the general population, and supplementing blind is how you end up fixing the wrong thing.

What Does a Race Nutrition Strategy Actually Involve? 

More than deciding which gel you are taking. 

A strategy covers what you eat in the days leading in, what you do the morning of, what goes in across each of the three legs, and what happens afterwards. That last part is the one everybody drops. Your race nutrition does not finish when you cross the line. It runs through the days that follow, and if you are racing again in six weeks, the recovery block is not optional. 

The other thing people miss is intensity. Practising your fuel on a Sunday long ride at conversational pace is not the same as practising it at race effort. Your gut behaves differently when you are actually racing, and that is precisely when you discover it. Never try anything new on race day. That includes the thing you tested twice, comfortably, at 20 beats below where you will actually be. 

Where Do Performance Supplements Fit in Your Triathlon Nutrition Priorities? 

Last. Number eight of eight, and only once the seven underneath are genuinely done.

This is the category everybody wants to talk about first: caffeine, beetroot, ketones, collagen, creatine, hydrogen water, wasp extract, beef spleen, the lot. A small number of these have real evidence behind them. Most do not. And even the ones that work are operating on the margins, which is exactly where you want to be operating once, and only once, the rest is handled.

The maths is unforgiving here. A supplement that delivers a genuine one per cent is worth having when you are already fuelling well. It is worth nothing at all when you are 400g of carbohydrate short across your race week. That is race tyres on a Ford Fiesta engine.

Frequently Asked Questions

Q: In what order should I fix my triathlon nutrition? 
A: Energy intake, carbohydrate periodisation, protein distribution and food quality first. Then hydration and electrolytes, then iron, calcium and vitamin D, then your race nutrition strategy, and performance supplements last. The order matters because each layer depends on the ones underneath it.

Q: Do I need a sweat test to work out my sodium needs? 
A: A sweat test is useful but it is a snapshot, not a permanent number. Sweat rate and sodium concentration shift with intensity, heat, acclimation and hydration status, so a single result from one session in one climate will not hold for every race you do.

Q: Should I take an iron supplement if I am always tired? 
A: Not without testing first. Fatigue has many causes, athletes need different iron targets than the general population, and taking iron you do not need is not harmless. Get bloods done and get them interpreted by someone who understands athletic reference ranges.

Q: Are performance supplements a waste of money for age-group triathletes? 
A: Not inherently, but they are almost always the wrong place to start. A supplement working on a one per cent margin cannot compensate for under-fuelling. Sort the seven priorities underneath first, then revisit.

Q: Does race nutrition include what I eat after the race? 
A: Yes. Recovery nutrition in the days following a race is part of the strategy, particularly if you have another event coming up. Most athletes plan meticulously up to the finish line and then improvise everything after it.

Bottom Line 

There is nothing complicated about the order. Foundations, then hydration, then micronutrients, then race strategy, then the fun stuff. The order itself is free, and I have just given it to you.

What free content cannot do is tell you which of the eight is your particular bottleneck, what your blood results actually mean for an athlete, or how much of what to eat around your specific training week. Everyone is different, and cookie-cutter is the enemy here. If some of this landed uncomfortably close to home, do not stress. It is a very fixable problem with the right guidance.

That is what we do inside the Triathlon Nutrition Academy. Not a meal plan, and not one size fits all. I teach you to build your own nutrition strategy around your training, your races and your real life, so you know how to do this for yourself for the rest of your racing life. Doors open a few times a year and the waitlist is the way to hear first.