Hydration lessons from Kona (and other hot races) by Iron Kaisa Jakobsen.

By Andy Blow | 4 Minute Read

Having raced in Kona four times now (placing 5th, 5th, 7th and 15th in my age group) and with two wins in Ironman Cozumel amongst other decent results in other hot long distance races, I've had to learn how to stay hydrated in the heat in order to maintain my performance. Fresh out of my latest Kona race, I wanted to pass on some reflections and tips for anyone racing in hot climates.

The conditions in Kona are incredible, it really is hot and humid, so it's really important to have a sound hydration and nutrition strategies to avoid both acute dehydration and hyponatremia, as well as maintain good energy levels. If you don't have that in place, your hard work in training and early on in the race may come to nothing late on.

I started my “nutrition” preparation a week before the race by drinking a bit more liquid and adding a bit more sodium in to my diet. I was also adding Precision Hydration 250 to some of my water bottles whilst I was acclimating to the heat.

In terms of nutrition, I tried to keep to my normal diet in the days leading up to the race day. I just paid closer attention to things like ensuring that I was getting enough alkaline food (fruits and vegetables, alkaline water) and that I was not eating too much fiber (bread, figs) especially foods that can increase the number of visits to the toilet on the race day!


Iron Kaisa talks us through some of her hottest race experiences


The swim at Kona is always tough, so I made sure to have some PH electrolyte drink just after the swim. I think this is often overlooked. The total time without drinking anything is about 1.5 hours from when you get in to the water and wait for the gun to go off until you get on to your bike, so as well as preloading before the race, it's important to think about topping up on sodium and fluids rather than just getting over excited and bolting off on the bike.

The bike course is hot and windy, with the latter mostly being head wind. This year I had a great feeling as I set out on the bike, but unfortunately I started with some bad luck. I think somebody had hit my bike in T1, because my gears were jammed when I set off, so I had to stop twice early on to fix this mechanical. Obviously this ate up a lot of time and I felt I needed to make that up to have any chance of another Top 10 performance...

Well, getting a penalty of 5 minutes at the start of the bike leg certainly didn't help that cause! (And yes, I accepted it, the ref said that I was less than 12m behind the bike in front, and thems the rules). On the plus side, that gave me some time to hydrate in the penalty box!


How to stay hydrated like Kaisa Jakobsen


I would need a special run to break into the Top 10 now. I came into the run well hydrated, and continued with the my tried and tested hydration plan. I had a PH sachet in a small bottle at the beginning of the marathon and then took SweatSalt capsules during the rest of the run. I'm lucky that I never have problems with cramping - or maybe it's not luck but rather that I have my hydration strategy sorted - and thankfully this time round was no different.

I had a solid run, so was happy with my effort, but not my 15th placing. But hey, this is what Ironman is about! You just never know what problems can occur on the day. It's a long day out there, and it's really difficult to have "the perfect day". All you can do is concentrate on your race and your hydration/nutrition strategies in particular. It's both a mental and physical game.

Upon reflection, I am satisfied. It was another great day out there. I came to the startline without problems and finished Kona well for a 4th time. Now time for a good rest and for the body to heal.

Tips for staying hydrated in hot climates


  • Take some extra salt/sodium in the last few days before a race and 1 1500 sachet on the morning of the race.
  • Use the Special Need station on the bike course if you want your own mixture, and be sure to get your sodium and sugar. It only takes 1 minute more, which is not so much in an Ironman! When I am racing Ironman distance, I want to have my drinks done before hand so that I can keep myself as aero as possible during a race, especially in a race like Kona where there is a lot of head wind.
  • Make sure you reach T2 with the right balance of sodium/fluids and carbs. During the run it is harder to take these in, and it's ok to hit the finish line getting low, but that should not happen before the last 10-14km.
  • Know your personalised needs! Mainly how much sodium you lose per litre of sweat, and how much you sweat. (This is why I became a Precision Hydration Sweat Test Centre, it's just a crucial part of the puzzle). Then calculate how much you need to be replacing during a race, create a race plan and keep to it (if it was working in training!). My sweat sodium concentration is 655 mg/l, so I take in PH 500 in 500ml about every 30-45min. I really like the natural taste of them, and the fact that they blend very well into water. The new range is also better to mix into bottles in my opinion, as they don’t sparkle and bubble out, like many other products.
  • Test mixing your PH electrolytes in with an energy product in training. The new all-natural mixes have a really mild taste and mix in well with my energy products without giving the mix a strong taste or horrible consistency.

Top tips for hydrating well in the heat


  • Drink too much plain water in the week before the race, especially in a hot environment.
  • Start with a gel straight out of T2, in my experience it's the think most likely to upset your stomach.
  • Drink the seawater during the swim ;-)  But, if you do, it's actually ok to stop and try to throw it up. If you don't it can block your intake of fluids and carbs that you'll need later on.

I hope these tips help you refine your hydration strategy and that helps you achieve your goals, whatever they are!


Kaisa Ilvesmäki-Jakobsen is a M.D Sport & Science, Cert. Sport Nutrition specialist by Sansego.co and a nutrition advisor for many top names in triathlon. Besides that, she's a passionate AG triathlete herself and has more than 10 Ironman finishes under her belt. And she's still going strong. Check out her site for more info on her awesome training camps and workshops. Oh, and look her up if you're ever out in Majorca and want to get your sweat tested ;-)

Was this article useful?

Share this article

Get your free personalized hydration plan

Take the sweat test