Ironman Florida 2017: Take 2

It has been sometime since my last write up but it’s been a really tough few months…


End of September I was involved in a bike accident where some idiot decided it was ok to reverse around a blind bend at the bottom of a hill with no signs or warnings he was doing so. I was out for a 4-hour ride and was the one who was his victim…

The result of the crash was double compression fracture of my spine (something I didn’t fund out until 3 weeks after the crash) as well as all the usual niceness of whiplash and bruising. I guess it was on the cards given the arseholes on the road and never been involved in a ‘real’ accident;  but when you’re building for an Ironman, accidents are a true disaster. In addition to that as a stress I have just moved to the other end of the UK and unfortunately for the family I was as much use as a chocolate fireguard in helping move.


Figure 1. Enjoying the removal of neck brace before finding out I have a compression fracture of T4/T5

Figure 1. Enjoying the removal of neck brace before finding out I have a compression fracture of T4/T5


Needless to say I have been and continue to have lots of issues with my back and neck, which has not fully healed so next stop, will be a MRI. In the interim I have been trying to get back into some training (approved by the orthopaedic consultant) after almost no training for 3-4 weeks post-crash. As I write this part of the blog I am 4 weeks out from Florida and have been trying to regain some lost form and have put in a few good rides and painful runs and swims (I have issues taking a deep breath due to injuries).

I have 4 weeks and ideally squeeze in 2 big days over the next pre-taper 2 weeks. Tomorrow and the following weekend will be big days and got to say am nervous as anything over 90mins (and any swim) has been leading to sleepless nights due to back and neck pains. However, as we all know once you have signed up for an Ironman the lure is difficult for reasons of costs (flights, entry already all paid for) and in my case I wanted to make the season worth it as had not beat my IM best despite spending a big winter and early summer getting in very good shape pre-taper for my main race at IM Frankfurt. I know I’m not the only one who feels the pressure to validate a season of hard training but maybe not the best idea.

Sometimes I feel the whole thing is madness as if the event was low cost and in UK I would have dropped out, as health is more important. I would never advise my athletes to do what I am doing in continuing to train when I should be 100% focused on recovery and getting my injuries resolved. So with making that decisions let’s turn back to Ironman Florida.


FLORIDA – Turn that frown upside down

In 2014 on a road bike, on the early stages of my Ironman journey and on the heels of a major storm I completed IM Florida. Back then there was no swim (a first I think is 14 years of the events history) due to the very bad weather. The race from recall was OK as it was pretty flat and not too hot, and despite a few punctures I enjoyed the ride and the marathon.

Flat and fast is what I love and given this time I will be a stronger biker (my race pace was my FTP back in 2014) I hope to at least crank out a better bike than my 5hr 53min bike from 2014…



In the run up to IM Florida I had my issues as above. However, in the 4 weeks prior to IM I managed to get in some good sessions although only 1 bike lasting 4hr 30mins I was ready to at a minimum get around the course.

In the run up to the race felt pretty calm and had a great shortened taper thanks to Dr Garry at SportsTest and made it through without any sign of a cold which has always been an issue. I was checked in and all prepped for race morning no problem. Come race morning I was up at 4.50am food in and then off to drop transition bags and make sure bike was in one piece and fully loaded and race ready.

Figure 2: Up and adam ready for the day ahead!

Figure 2: Up and adam ready for the day ahead!


Check in was fine and made it down into the swim start and slotted into the sub 1-hr group. Swim was always going to be a bit choppy and it’s a strange old swim as the level of the water remains shallow for a good 100-150m from entry so you have a few meters where you can dolphin and the rest your wading out. The 1st lab was fine and I was a little cautious on my effort as swimming had been causing the most issues in my back (t4/t5) where the fractures had happened from the crash. Although I had done bike to run brick work during training I had done no swim bike and was just hoping all would be OK. After getting in for lap 2 the orange markers had significantly shifted.

Figure 3: The start of the day and end of lap one.

Figure 3: The start of the day and end of lap one.

I don’t know if they had become untethered but a lot of people had began to swim out very wide away from the direct line to 1st turning buoy (was red). I asked a few others who where also lost wondering what was going on but no one knew so I decided just to head for the red buoy and if the wrong line the refs in the water would tell me. It was the right choice but the dicking abut burnt some time but as long as I got out and the back was in one piece it would be a thumbs up.

Swim [1hr 05mins].



I don’t often talk about transitions but Florida is 100% on the ball – yes it’s a long transition from beach to change to bike and you cannot have your shoes on the bike but the staff are all over ready to make sure your get to your bike. In my situation I was very near the transition exit making finding the bike easy and when you get to the change tent the volunteers are waiting for you with your bike change bag. No mean feat with 3000 athletes. Similar, getting of the bike you had over your bike as you cross the line and the volunteers rack and also hand you your run bag making for a super smooth transition. Other IM events could learn a lot from Florida.



Following the weather it was forecast to peak at about 3 hours into the bike at 80of but very little wind so real feel of 90oF. For me I was not concerned but I knew if would be a factor on the run, so hydration pre and post swim as well as on the bike would be key. Got to say I felt good on the bike on the lead out and perhaps a bit to over eager with exceeding my race watts by 10-15watts. That would be fine in a cool European event but given the heat in Florida I wanted to ease off to make sure I was leaving some in the tank for the run. I also had done only one long bike in 12 weeks leading up to the race so what was in the legs I didn’t know.

Figure 3: Time to hold the aero and get head in the game.

Figure 4: Time to hold the aero and get head in the game.

After the 1st hour I had settled in and from where I was after the 1st hour I didn’t see any drafting, which is what Florida has had a reputation for. I don’t know if this was due to increased marshalling or some change in the way age groups are now approaching races but it was useful and allowed me just to think about my own performance without to much surging etc.

Out on the course my mind was on 2 things .1 holding aero position and 2. Nutrition, nutrition, nutrition. I try to get in at least 1000mls an hour although I know I will sweat more than this. I have been up to 1200mls/hr previously but just not had enough time to get in the sessions to adapt. However, as long as I can hold my aero position I can get away with lower watts for a better return in speed (note: my CDA for Florida was 0.223 m^2).

Over the last 30Mins I was beginning to feel the ride become a bit more of an effort than the ease the rest of the race so held back another 5watts, hoping it would leave me with some legs for the run.

Bike time [4hrs 53mins]



Dam, Dam hot…That’s the summary for the Florida run. I jumped of the bike out of transition and have to say felt ok and tried to settle into a 4.40-4.45mi/kg pace of running and until about 14/15k (See Figure x.x) I was bang just under a 4.35average (to get me under a 3.15 marathon and circa 9hr 20Min IM based on the days swim/bike– p.s. that would have given me second or 3rd in age group and kona slot) then the heat (or maybe just the lack of training) started to kick in….

Figure 5: Feeling good on the run well at least to 14km ha

Figure 5: Feeling good on the run well at least to 14km ha


The rest of the run was ok high and lows but manageable but could not hold the speed and hard to keep body temp down despite lots of ice at aid stations and remaining hydrated. I had not done anywhere near enough the acclimatisation work I had done for Frankfurt and I could feel that on the day. Frankfurt’s peak heat was higher than Florida but I felt easier at Frankfurt heat wise so something I can cope with but need to do the right preparation.

Figure 6: Hot hot hot...even from the start.

Figure 6: Hot hot hot…even from the start.

So the run became a case of grinding it out but with no real walks of shame only walking the aid stations after about 15k I was pretty happy to make it through, given the last few months of not even knowing if I would make the start line.

So come the end of the run there was the lovely finish shoot and unlike in 2014 I finished in the sunlight and was great to see the family and my Mam who had come over for her 70th birthday. Despite nipping under the 4Hr mark for the run I was well away from the 3hr 27min run I did in 2014, which if I could have put together on the day would have given me my goal of a Kona slot. But these things are here to tease but a sign for me that I have it in me.

Figure 7: Not long after this one the shit hit the fan.

Figure 7: Not long after this one the shit hit the fan.

Post analysis I improved from 2014 but a poor run and lack of training let me down on the day and although I didn’t aim for Kona on this race but a finish holding together my run from 2014 would have got me to the island. There have been improvements since 2014 results but the only number that really matter are 1-4 i.e. the finishing slots guaranteed to get you to Kona and that’s got to be the goal again for 2018.

  • 16th Age group (Up from 52 in 2014)
  • 96th Overall (Up from 275 in 2014)

Overall IM Florida 2017 [10hr 6min]

Figure 8: On the way to ice-cream and beer

Figure 8: On the way to ice-cream and beer


SUMMARY – A Year to forget or remember!

I have had a great year of training but a crap year for results. I am sure everyone has them but you always are looking for validation of your efforts but you have to look to your long-term goals, evaluate and fix what maybe broken in your strategy. You will always get those looking to the failure in a result or you not achieving x but every season and indeed every race brings new insight. The application of that insight to you micro, macro cycles in training, your diet and recovery are all key.

The pro’s for this year for me is I have finally understood how to acclimatise for the heat that’s to Frankfurt. 3 weeks having a mix of steam/sauna and hot baths post training do the job. I am never going to be an optimal athlete in the heat as I carry too much muscle and simple thermodynamics come into play here. However, managing and still performing to ‘my’ best ability in hot conditions is key to a good performance if not the fastest race.

I also believe a shortened taper works best for me. I felt so much better going into Florida than any other IM, so despite the lack of long bikes I think I had a good race.

Negatives of the year have been my 1st real bike crash and I am writing this second part of my blog a week post IM Florida and another night of poor sleep due to continued back pain. I am in for my MRI and hopefully the issue is just muscular and I just need time post the fractures. I will keep up with the physio and osteopath sessions and the latter are a massive help.

Although the race times for various reasons of health have not been fantastic I have learned this season and become stronger on my bike. It’s the start of the off-season and I’ve had a week of very little post Florida so I guess its time to get back on it. It’s been a busy work year from the day job and setting up some other projects but some very exciting stuff in the pipeline for 2018.

“Wishing you guys a very happy xmas and all the best for your winter training!”




Roll on July 9th

That was the thought process in the months leading up to Ironman Frankfurt. I felt ready and was shooting out some great training sessions as well as some long training hours, effort and coin on route to what I though would be a big PB.

Pre-race blues!

One thing that seems to be common across those involved in long course triathlon is the dreaded taper illness. In 2016 I was victim and ended up ill pre-Austria making me jump into Ironman Barcelona to validate my years efforts, which I did with a PB. However, I was hoping I would be able to avoid such issues this year but for those following me on twitter (@marktallonphd) a week out I ended up with a bacterial chest and throat infection – so out came the anti-biotics. It was a case of fingers crossed that I would be ready for race day!

T-Minus 48Hours

What a week…So a week out I picked up the illness and pretty much did nothing training wise other than try to recover for race day. Then day of flying out I was told my grandmother died – so some icing for the shit cake I was dealing with. There was also a load of work stuff to deal with for both wife, and myself but maybe go into that in another blog.

As you guys know you invest not only significant time but also cash into preparing for an Ironman. Physio, bike kit, nutrition, coaching, flights, hotel, entrance fees all add up to £1000’s of cash. So many of us go against what we know is right i.e. to pull out. I would never advise an athlete to race when ill other than head cold but once on the chest and green chunks there are some real health dangers to racing like that – so I must be a bit of a nob as still raced.

48hours out and I decided I would race and I needed to get my head into the right space. Before I get into the story of the race the goal was sub hr swim, 4hr 45min bike and a 3.10run – all on the cards based off my training leading up.

Bike Check

For those who don’t know the swim start and T1 are across the city from T2 for Ironman Frankfurt. So the day before the race you need to grab your bike to get checked in by taking your bike onto a bus with the other 3116 registered athletes. The bus journey was about 40mins and as you can see by the pick the queues are pretty big and at over 30oC you’re sweating your nuts off for about 30mins before getting on-board. I have to say the operation is slick and there are lots of busses so don’t stress about getting to racking in the 1st bus to go.

Figure 1. Bike queue for getting the ride to T1

Figure 1. Bike queue for getting the ride to T1 – All around the block…

What I would say is for those of you who are staying near the city and my not get an opportunity to try out the swim is to bring some swim kit so after racking your bike you can get on the swim course. Again getting back into Frankfurt is hassle free as lots of busses on for the return journey.



One of my previous issues during Ironman was getting my ass out of bed in the Morning in enough time to make sure I was not rushing to race start and could get a warm-up in. This time set my clock early so we where out of the door 4.35am to get the bus (yes you can bring family) to Swim start (T1 opens at 5am). I got there in good time to check over the bike and load food and drink for the day and managed to get into the water for a good 10min warm-up. The lake is stunning, very flat and easy to see the markers, so I stuck my self into the sub hour group.

Swim [1hr 46seconds]

Prior to the start of the swim I felt pretty good. I was still coughing but didn’t feel to bad and had completed the antibiotics the day before the race and had a good sleep. Got into the swim which is a wave start and there seemed to be lots of space. In hindsight I wish I had been a bit more aggressive but was not sure how I would feel. In the end was an OK swim and felt pretty comfortable post swim.

The transition was a long run up to the bikes and changing area. I had already scoped it out pre race so I knew what was to come. I had no issues during transition and out on the bike in ok time (T1 = 6min 46seconds).


Bike [4hr 57min 18seconds]

The bike was short this year by a supposed 3km (My Garmin says 6k). Like all Ironman the bike is a make or brake for the rest of the event and I was looking forwards to it after some great rides in training. After the 1st 10k my power was down about 20watts from target effort and this was the concern – what impact of the illness. However, I had decided whatever happens I would finish the race and work as hard as was comfortable. Despite not being able to hold a higher power I enjoyed the bike. There was very few out on the course and that would mean I only saw one instance of drafting – so a real honest course – just how Ironman should be.

Figure 2. Out on the bike and into the fryer.

Figure 2. Out on the bike and into the fryer.

A few tips for those of you that might be interested in doing Frankfurt. There are a few places with cobbles and these are real boneshakers. I used 28c wheels for the race and 90psi to try to absorb some of the shakes but lost my chain over one of the sections. So key for the cobbles is to keep spinning the legs as your go over them as any slack in the chain when not pedalling can make the chain more likely to jump off.

Figure 3. Frankfurt cobbles, shake rattle and roll.

Figure 3. Frankfurt cobbles, shake rattle and roll.

Over the second half of the course I dropped another 6 watts but on the plus side did get in all my nutrition / fluid on the day, which was a concern as antibiotics can ruin gut function. This was key as mid bike the temp was already heating up to a toasty 32oC. I had done 10 days pre race heat acclimatisation work and got to say it worked a treat as even with a TT helmet on I did not feel fried.

Coming off the bike I was ready to get a quick transition and had feet out of the shoes ready to hand my bike to waiting staff. Once off the bike I ran to my bag (which I had market with black permanent marker to ensure it stood out from the other bags). On arriving at my race number the bag was gone from the hook (Yep fucked off is an understatement). I called a member of staff over to help out but they where as useful as a chocolate fireguard – after some running around I found it about 5 meters away under another rack. Clearly someone must have picked up the wrong bag realised it and dumped it (Thanks). Panic over but maybe 1-2mins lost resulting in a 4min transition when you could do this in 2mins.

Figure 5. Out of T2 ready to attack the sweltering run.

Figure 4. Out of T2 ready to attack the sweltering run.

Run [3hr 57min 21seconds]

Out onto the run a felt OK (As good as you can feel post bike leg) and tried to set off at pre planned 4.20/4.25 pace. After 5km this felt tough and the cough was back in full effect so I slowed it down trying to hold around 4.45min/km. Despite averaging this up until 24/25km into the run the cough was constant and the next thing I was laid on the floor then being carried of to the med tent. After about 15mins in the med tent I was allowed to go (I had blacked out due to low blood pressure from the coughing).

Figure 6. Never quit no matter what!

Figure 5. Post med tent back to work – Never quit no matter what!

By the time I got running I had lost about 20mins (Stuck the run splits at the end of the blog for those interested). However, after dropping out at Austria in 2016 I promised I would never quit another Ironman, so on I went and pushed as much as I could holding around 5min/km pace over the rest of the course. I guess without the stop I would have been around the 3.30marathon time, which would have been all things considered and OK race and a PB.

Figure 7. The finishing shoot plays feels so good!

Figure 6. The finishing shoot feels so good!


Despite the failure in making my goal race effort, I learnt a massive amount about myself over this race.

  • 1st – I now know what I need to do to acclimatise for a hot race, which has been an issue for me in the past.
  • 2nd – Even when I am not in best form and have a disaster out on the course I can still push close to a sub 10hr Ironman.
  • 3rd – The experiences of hard races over the past few years and the failures have strengthen my mind so when the wheels come of I can find the motivation to carry on.

So despite not getting the race nor the outcome of the race I wanted I felt proud of the effort I had put in. After a few days reflection I have signed up to a race I did back in 2014 – ‘Ironman Florida’.

Figure 8. Amazing how quick you can forget the pain when you grab the gold.

Figure 7. Amazing how quick you can forget the pain when you grab the gold. Remember why we do this sport – for the love of it!

Writing this Race Blog is a bit delayed and it’s now 2 weeks post Frankfurt and still not 100% over the cough. So far I have only done a few easy sessions to keep the legs spinning. However, I have really needed the break with so much going on in personal life and being training solid for the last 7months have taken their toll.

I have loved the break both physically and mentally but I am ready to get back to it from 1st week of August and will use the next week as a run in pre training proper. So another 12 weeks of graft are ahead for me and I feel mentally recharged and ready to attack. Best of luck to all of you for the rest of the season and remember avoid the doubters as there are no limits other than those inside your mind! #believe

Best in training, Mark


Salt Supplementation & Sweat testing for Ironman – Why it’s not about cramping!

my salt picOld wives tales are great for getting the kids of to sleep but should serve little or no place in Nutrition Science. However, we have the persistent commentary that salt supplementation prevents cramps in the same manner lactate is rolled out by the TV commentators as the cause of fatigue. In this article I want to dismiss some myths about salt/sodium use, sweat testing and how to integrate the information from this review into your competition nutrition safely and effectively.

Before we begin there will be some science here as much of the marketing of salt and sweat testing is positioned on scientific precision and evidence. However, we rarely see what science underpins their testing and related claims. As such I have fully referenced this article with the scientific studies used to form my views on salt supplementation and related sweat testing. If you are short on time simply jump to the, ‘HOW TO USE GUIDE’ at the end to see the application of the research and information from the article.

Figure 1. Me and salt loss post Barcelona marathon (see salt on clothes)

Figure 1. Me and salt loss post Barcelona marathon (see salt on clothes – Salty sweater? So what…).


Historical BS

The place of salt as the cause of cramps hails back almost 80 Years to studies on Miners working underground in high temperature environments.[1] In a study on 1 single miners urine subject to cramp (although not cramping at the time the sample was taken) had the levels of chloride that was almost absent (note: chloride was used at the time as a marker of sodium levels). [2]

This absence of chloride in the urine according to the authors of the study suggested an excessive shortage of chloride (and as such sodium) in the blood. However, it was known that sweat contains much lower levels of salt than in the blood, so as sweating (loss of more water than sodium from the blood) continued the level of sodium in the blood would actually concentrate.

The study author was aware of some animal data that demonstrated that animals forced to ingest large quantities of water developed muscle twitching,[3] and from that the miners cramp must be due to excessive water consumption. Therefore, the author decided to develop a solution that had a sodium chloride solution (0.51g sodium/500mls) (double that in lucozade sport), and test it on miners as a means of preventing cramp. The effect of this drink on 7 miners where that only 4 felt it benefited them (not exactly an endorsement for this level of intake).

The result of the study from the authors point of view however was that cramp due to sodium loss was made worse by excessive water consumption. Then in 1929, Hancock et al. proposed that[4] since drinking water will continue a drop (loss) of chloride (and sodium) in sweat from the blood; salt will move from the cells (including muscle) to maintain blood sodium concentrations (maintenance of osmotic pressure).

Under resting conditions the kidneys would expel excessive water and as such retain sodium and chloride levels in the blood. Yet according to Hancock and colleagues it was thought that during exercise blood flow is diverted to muscles and skin and thus making the kidney ineffective. The result is a continued loss of sodium/chloride in the sweat and due to water ingestion a continued lowering of the levels of sodium/chloride in the blood (despite not actual evidence in humans demonstrating this effect). By the 1930s Dr Talbott of Harvard concluded that when a critical level is reached in the working (exercising) subject, muscle cramp would occur.[5] The obvious solution here was to ingest more sodium as suggested by Dr’s Moss and Haldane.

A big problem with the theory of sodium depletion based muscle cramping is that there is almost no evidence demonstrating during prolonged exercise subjects with reduced serum sodium vs. those with normal serum sodium have more cramps. There is also importantly no real evidence to demonstrate total body sodium depletion or its depletion in muscle. This must be key issues to demonstrate as it’s the muscle that goes into cramp not the blood. So if the intracellular sodium pool is not different between those cramping and those not Cramping then can sodium depletion be the cause?

“Before I go on to cover this issue further common sense is always a great guide. For me if I do a run prior to a swim I get cramps in my clalf’s. Now if cramps are due to sodium deficiency / depletion then why are only my calves effected rather than all of the muscle in my body? The vast majority of triathletes out there experience cramps at many times where they are still in a very hydrated and non-sodium depleted state (or even during sleep), again how does this support sodium depleted theory of cramping?”


Salt Stores in Human Body: Salty sweater are they relevant?

Typical sodium concentrations in sweat are 20-80mmol/l (460-1840mg per litre) and in workers exercising at relatively low intensity in high temperatures for 10 hours may (not actually occurring but predicted from hourly loss) have sweat losses of 10g sodium (Na) or the equivalent to 25g salt (NaCl) per day. Without external intake this would be a loss of 50% of the total body stores.[6] Given the role of sodium in muscle contraction, nerve function and indeed blood pressure; then the sodium loss can be theoretically important. But weather you’re a light (20mmol) or heavy (80mmol>) sweater we must consider the reality of what happens during an event as almost all athletes take on some sodium in drinks and foods that are on the course.

In addition we must consider that the body will try to excrete excess sodium and retain sodium when intake is too low (providing the kidneys function correctly). The potential issue with this is when too much water is consumed and too little sodium – the result is hyponatremia (dangerously low blood sodium levels.) Of course on a daily basis too much sodium can increase blood pressure due to the retention of excess blood volume. As with everything there must be balance for health.

The problem with most published endurance studies looking into sodium depletion and cramp is we do not see sodium depletion occurring as measured in the blood (extracellular fluid). This maybe as a result of the release of sodium from other body stores. At this point despite the development of magnetic resonance imaging[7, 8] for real time measurement of Sodium within the muscle (in and out of the blood) and other intracellular organs its not usable in the field (i.e. what happens during an Ironman). What we do know is that there is no proven relationship between sodium loss and cramping in healthy athletes.


The alternative theory of Muscle Cramping

There are at least 2 other theories that suggest a cause of muscle cramping beyond the dehydration/electrolyte hypothesis. The 1st relates to an extension of the action behind how dehydration & electrolyte loss may cause cramps by increasing pressure placed on nerves (due to a loss of the interstitial fluid surrounding the muscle cells and nerves) and a build-up of excitatory neurochemicals. There is no evidence in humans to support a such a change in pressure or build up of these chemicals. The 2nd theory relates to altered neuromuscular control.[9. 10]

This latter neuromuscular model I believe is in the vast majority of athletes the primary cause of muscle cramping during exercise. From my own experience, cramping of my calf’s during swimming post-run (not dehydrated post run) would mimic what has been demonstrated in laboratory models used to bring about muscle cramp. So I do a run (I run off my toes) and as such the muscle is in the shortened (contracted) position (i.e. toes pointed down). Then I go for a swim and again my feet are extended (plantarflexion) and point behind me. In both exercises the muscle in in the contracted (shortened) position.

In lab tests trying to bring about cramping in a repeatable manner demonstrate performing exercise with the muscle in the shortened position followed by some free exercise then followed by exercise of muscle in shortened position again brings on muscle cramp.[11] Similarly, models where electrical stimulation to shorten the muscle and hold it in that position brings about cramp.[12, 13] These studies in conjunction with the lack of evidence demonstrating that cramping and non-cramping athletes are not related to levels of sodium loss/dehydration indicate a neuromuscular basis for cramping.

For me personally – the mechanism of cramping on the function of the body is interesting ‘academically’. However, my real interest and probably for most of you reading this is how do I prevent it? If dietary what do I do? How much of x? When to take? And what’s the benefit (Performance)?

So lets look at some the action points from the research and how it’s useful to you as an athlete.


The continuing benefit of sodium use for Ironman

Excessive fluid loss does impair performance, and we know this from many studies. But the level of fluid loss is important. A few KG’s may actually be beneficial towards the end of an Ironman race with data on elite athletes nearly always demonstrating the fastest performances are those with the greatest levels of fluid loss (up to 8% of bodyweight i.e. 5kg for a 70kg athlete).[14] Whilst this topic on dehydration is a whole other area the academic debate contained in reference 14 is a good start for a discussion of some of these issues.

In Ironman we are not just talking about loosing 2-5kg in bodyweight. If we had a sweat rate of 1ltr per hour that’s a potential fluid loss over the event of 15-16ltrs. Of course this is impossible as we would have developed sever dehydration and heat stroke well before that level of loss. But it demonstrates a potential performance risk and that to get through such an event an adequate hydration strategy is required to maintain health and performance.

My own view on the benefits of salt (sodium) use during prolonged endurance exercise like Ironman is its effects on hydration rather than any effects that are related to cramp prevention. This has been demonstrated in many studies but my favourite is by Professor Maughan and John Leiper.[15] In this study the take home for subjects exercising until they lost about 1.5kg of body weight through sweating, could hydrate to a much greater degree the more salt that was present in their hydration drinks (See below for more detail on the study).

Therefore, what are the practical considerations from such research? If your sweat rate is over 1tr per hour (Mine during a run can be as much as 1.5trs) then it becomes very difficult to take on board that level of fluid to make sure you maintain your core temperature and hydration levels. Although its possible to train the gut like any other organ in the body to tolerate such high fluid intakes, for many its very difficult and forcing in such levels could result in gut issue during a race. As such the supplementary intake of sodium can be a great option to enhance the retention of what you do take on and as such reduce the risk of dehydration of ultra-endurance events such as Ironman.

In addition the amount of carbohydrate in your sports drink will also play a role in hydration and the lower the levels of carbs the more hydration but likely less energy taken on board. The high the concentration (amount of carbs) of carbs in your sports drink the less hydration but more energy delivery. As such there is a trade off between hydration and energy delivery but the prevailing view is a concentration of about 5-8% carbohydrates (that’s 25-40g carbs in your 500ml drink) is a nice option. As this article is primarily about salt/sodium we will revisit carbs in another article.


A word on ‘sweat testing’ for athletes

There has been a big push for athletes to measure (have tested) the amount of sodium you loose in sweat. There are a number of issues with such tests I want to discuss before you go and burn some cash on this type of testing.

Firstly, as you loose water through sweating the body will try to retain sodium. Secondly, dietary changes in salt intake will impact the levels of sodium you loose during exercise (example during winter months your salt intake maybe lower than summer when you use more sports drinks containing salt). Thirdly, the suggestion is sodium loss is the cause of cramping when as above we have demonstrated this is not correct. Finally, most of these tests assess sodium loss (they actually look at chloride release) on one point in the body (example forearm). It is know that sweat rate and sodium loss is dependant on where the measurement is made (arm vs legs), and when the measurement is made (point of fitness during the season, environment) and as such any one off measure for whole body sweat rates during exercise is questionable.[16] What is know is that the most accurate way to assess sweat rates is via weight loss and I will discuss this to a great extent in the ‘HOW TO GUIDE’.

One of the common test (Iontophoresis) is the placing of a chemical (Pilocarpine) onto the skin and an electrical current placed into the skin to elicit sweating (This is not a new test and can be traced back to 1959). There are a number of issues with such tests for athletes. Firstly this method has not been validated for use in athletes (its use was for cystic fibrosis patients) as an indicator of whole body seat rates. It also is highly variable in terms of its accuracy with results from test then a re-test showing 18% variability in the results.[17] In addition research also shows that in athletes steady state sweat rates do not occur until 20 -30 minutes of exercise which is key for applying techniques to predict whole body sweat rates from an isolated part of the body.[18, 19] In addition the research shows that sweat rate is significantly higher with exercise and thermal stress compared with Pilocarpine Iontophoresis.[20, 21, 22]

Figure 2. Pilocarpine a chemical used in sweat testing

Figure 2. Pilocarpine a chemical used in sweat testing.


The reasons for such difference are pretty common sense as local (forearm) sweat stimulation from a electrical impulse and Pilocarpine is that during exercise and heat stress there are alterations in blood flow, neuromodulators, adrenergic stimulation etc. Therefore, its of no surprise that the test alone (even by companies using it) is normally not relied as delivering a answer to sweat and sodium loss rates. Instead testing companies implement questionnaires into the discussion, suggesting the test is little more than a gimmick to make the whole process more scientific.

Finally, if there is an optimal level of sodium for each person than how can we square that with studies such as that of Professor Maughan and John Leiper?[23] In this study the authors provided 1 of 4 drinks following exercise that resulted in 2% loss of body mass (circa 1.5kg). The drinks where at a volume of 1.5x the loss of bodyweight (circa 2.25ltrs) post-exercise, with the only difference in the composition being the sodium (salt) content.

The dose of salt was 2 (46mg), 26 (598mg), 52 (1195mg) or 100mmol (2300mg)/ litre of drink, which was consumed within 30 minutes following exercise. Drink volume 2.25ltrs within 30minutes. The results demonstrated that the higher the sodium concentration the great the fluid retention in the following 5 and half hours post exercise. However, although the difference between the 1.2g and 2.3g was not significantly different from each other based on fluid retention. As such a dose around 1.2g was the optimal intake for rehydration in these subjects.


Evidence for sodium intake benefits in Triathletes

As I said the important part of all this discussion is to demonstrate practical application and where possible evidence for benefits. In 2016 researchers from the University of Spain assessed the impact of salt supplementation on half Ironman performance.[24] A group of 26 experienced (7-8yrs) All the participants were instructed to take 867mg sodium (plus 1.3g chloride, 265mg potassium, 44mg magnesium) during the transition between the swimming and cycling sections, the same again around the middle of the cycling leg, and again during the transition between the cycling and running sections. The subject would either be given the salt formulation or a placebo (cellulose) without knowing. The temperature during the event was 22.5+/- 2.7 °C (18.8–26.6°C) with a relative humidity of 36.8 +/- 8.3% (32–45%), the swim 17°C.

The results of the study demonstrated quicker race time in the salt group vs. placebo with sweat loss and sweat sodium similar between groups. However, weight loss tended to be less in the salt vs. control group. Furthermore, post race blood sodium levels where also higher in the salt group. The take home of the study according to the authors was, “Oral salt supplementation was effective to lessen body mass loss and increase serum electrolyte concentration during a real half-ironman.”

So what’s the take home from this everything from this article?



1. Calculate fluid intake based on real fluid loss (whole body sweat rate): Void your bladder pre-exercise then weigh yourself naked before exercise. After an hours exercise at intended race pace and temperature whilst also taking on board your intended drink at 500-1000mls over that hour weigh yourself again. When you have the weight loss take into consideration how much fluid you consumed over the hour. Example: Starting (pre-exercise) weight 72kg – post exercise 71kg. Fluid consumed over the hour 500mls. Total sweat rate = 1kg + 0.5kg = 1500mls/hr.

2. Sweat rate can vary between days in the order of 5-15% so your sweat rate using the example above could be 1500 +/- 75-225mls. Therefore, you should practice consuming during training at least replacing what has been lost during exercise. This may require practice and training so perhaps starting at 800mls per hour and increasing 100-200mls each week (depending on how your gut reacts).

3. Sodium would be suggested at 500-1000mg/ltr of fluid (ideally closer to 1000mg). Note that again individual tolerance to sodium can vary so practice in training.

4. Carbohydrate composition: Suggest using a glucose or maltodextrin plus fructose based drink at a dose of 5-8%. So for 500ml bottle you would place 25-40g into your drink bottle and fill it with water. Again practice using different concentrations of carbohydrate. Note: Maximum levels tolerated of mixed (glucose:fructose) carbs are 60-90g/hour although adding caffeine may also be beneficial.

5. Be careful of using commercial sweat testing be sure to ask: 1. how they know their test works in athletes, doing your sport (evidence), 2. is the test reflective of whole body sweat rates (evidence?), 3. Relevant in predicting sweat rates in the environment you will be competing in (hot/cold/humid etc)(evidence?).

If they cannot provide a study to shows the test and predictions are correct then you should consider why are you spending cash when you can use the free method above that would likely be as or more accurate.



Note: A special thanks to some of the thought leaders in the area of sodium and salt supplementation for endurance athletes specifically Prof Tim Noakes. Whilst I don’t agree with all Dr Noakes concepts and ideas he has been willing to push back against much of the scientific dogma regarding salt use in endurance sports. Its key to let your mind be flexible to new ideas and concepts and not read research with pre-conceived ideas and views and let the data (the raw data) speak for its self. For that reason Dr Noakes has been a leading figure.

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23. Supra Note 15

24. Del Coso J, Gonzalez-Millan C, Salinero JJ, Abian-Vicen J, Areces F, Lledo M, Lara B, Galo-Salazar C, Ruiz-Vincente D. Effects of oral salt supplementation on physical performance during a half-ironman: A randomized controlled trial. Scand J Med Sci Sports. 2016: 26: 156–164