Evidence-based supplements for triathletes and endurance athletes | EP#193

• The paper came about due to the initiative of the International Olympic Committee, specifically their medical and scientific commission. 
• They gathered a panel of experts to discuss the place of dietary supplements as part of the nutrition and training strategy of high performance athletes. 
• This resulted in a consensus statement that was also submitted to the British Journal of Sports Medicine, where it was accepted and published. 

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• This includes things like sports drinks, gels, bloks, electrolyte replacement, protein supplementation etc. 
  
  Things that give you easy access to certain nutrients or energy that you may not get enough of otherwise. 
• Sports drinks can be used to provide carbohydrates, as well as sodium and some electrolytes. 
  
  This is supported as something that can be used during exercise, and post-exercise for rehydration and refuelling. 
• Energy drinks (e.g. Red Bull) can be used to provide carbohydrate but also caffeine and other ingredients. 
  
  This is supported as an alternative during exercise, and could be used as a pre-exercise caffeine supplement. 
• Sports gel, or similar (e.g. bloks) are recommended as a way to get in carbohydrate during extended or intense exercise. 
• Electrolyte replacement supplements (e.g. drinks with mostly electrolyte not carbs) are recommended for rapid rehydration following dehydration during exercise. 
  
  They can also be used for replacement of large sodium losses during endurance activities. 
  
  For more information on these drinks check out: ​Hydration in endurance sports: a Q&A with Andy Blow | EP#191​​​
• Protein supplementation (e.g. powders, ready to drink liquids and bars) are recommended as post-exercise recovery following key training sessions or events where adaptation requiring protein synthesis is desired. 
  
  They are also recommended for achievement of increase in lean mass - but this is more for resistance training and strength and power athletes. 
• If you're doing hard, or long sessions where protein synthesis will be a key part of recovery and adaptation, then protein supplementation can be helpful. 
• Liquid meal supplements, which contain 15-20% protein and 50-70% carbohydrate, can be recommended to supplement diet with high energy demands. 
  
  It can also be recommended as a low bulk meal replacement, for example pre-event. 
  
  Also potentially as post-exercise recovery as you're getting your carbohydrate and protein. 
• Bars which typically include 40-50g carbohydrate, and 5-10g protein, usually low in fat and fibre are recommended as a potential carb source during exercise. 
  
  They are also recommended as post-exercise recover, particularly when they provide enough protein. 
• Finally, protein enhanced food is recommended - e.g. milk, yoghurt, ice cream, cereal bars, and other food forms that have added protein. 
  
  These are listed as value added food able to achieve protein target for post-exercise use, or to improve protein content of other meals and snacks in the athletes diet. 

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• There are a few supplements with good to strong evidence for achieving performance in specific scenarios. 
  
  For triathletes there are two: caffeine and nitrate.
• For endurance athletes competing in short events - 10 minutes or less - there are two more that can be useful: beta alanine, and sodium bicarbonate. 
• There is one more supplement that generally has a lot of benefits for athletes: creatine. 
  
  However, these benefits are mostly related to strength and power. 

Caffeine

• Caffeine is the most studies and has the best evidence for endurance athletes. 
• Caffeine is a stimulant that has well established benefits for athletic performance across endurance based situations. 
  
  It also has benefits on short-term, supramaximal or repeated sprint tasks. 
• The protocol of use for caffeine is to take 3-6mg/kg body weight, 60 minutes before exercise or racing. 
• During exercise and racing, you can take lower doses (less than 3mg/kg) which is recommended to be consumed with a carbohydrate source.
• Caffeine has been shown to increase time to exhaustion, and has improved time trial activities of varying durations from 5-150 minutes across numerous exercise modalities. 
• The range of impact has varied quite a bit and is not specifically listed.
• It is stated that lower doses of caffeine - 150-300mg - consumed during endurance exercises after 15-18 minutes of activity may enhance cycling time trial performance by 3-7%.
• Usually it is the case that more advanced athletes have lesser benefits than less advanced athletes. 
• Larger doses of caffeine - more than 9mg/kg bodyweight do not appear to increase the performance benefit and are more likely to increase the risk of negative side effects.
  
  These include nausea, anxiety, insomnia and restlessness. 
• If you do consume caffeine during activity it should be done concurrently with a carbohydrate source for improved efficacy. 
• As with any supplement you're going to take during racing, you need to practice it in training to discover what the optimal timing and amount is for you specifically. 
• ​To give some real world examples of caffeine amounts:
  
  In a brewed cup of coffee there is on average 95mg of caffeine, which is quite a low dose for somebody at 60kg (it would be 1.5mg/kg bodyweight). The range is 70-200mg though as it depends a lot on the roast. 
  
  In decaf coffee there is 2-3mg on average. 
  
  In a shot of espresso there is on average 63mg - which would be 1mg.kg bodyweight for a 60kg athlete. 
  
  In a cup of instant coffee there is somewhere between 65-85g of caffeine. 
  
  In a single shot latte there is between 47-75mg of caffeine. 
• If you're considering caffeine supplementation, coffee is not the way to get caffeine, you need to go for specific products. 
• Personally I use Science in Sport caffeine shots, which contain 150mg of caffeine. 
  
  I weigh around 70kg so this would be just under 3mg/kg bodyweight, so it's still on the low side of things! 
  
  For me, two shots would be a bit more than 4mg.kg bodyweight so that might be just right for me! 

Creatine

• There's a lot of evidence for creatine, and it is great, BUT this is for power and strength athletes mostly. 
• I checked the paper to see if there was a use case for endurance athletes but there doesn't seem to be. 
• If you're a strength athlete and endurance athlete and interested in bigger gains, it may be worth looking into creatine more.
• It's one of a few supplements that does work and has a proven evidence base for it. 

Nitrate

• Nitrate is found in foods such a beetroot. 
• In the recent decade it has been researcher more and we are starting to see the evidence grow that it can be a helpful and beneficial supplement for endurance performance. 
• The protocol in the paper is to supplement with 310-560mg 2-3 hours before activity. 
  
  Also prolonged periods of supplementation appear beneficial to performance, especially in highly trained athletes where performance gains from nitrate supplementation appear harder to gain. 
• Supplementation with nitrate has been associated with improvements of 4-25% improvement in time to exhaustion. 
• Time to exhaustion is not as good or as rigorous a test as a pure time trial as there's a lot of variability and psychological factors. 
  
  Time trial performance assessments are the gold standard. 
• Looking at time trial specific improvements the range is 1-3%. 
• Referring back to the Andy Jones episode, he was conservative but he talked about typical performance benefits of 1%, but he does work with a lot of elite athletes. 
• There are a few side effects of nitrate that may cause some limitations: 
  
  Some athletes are susceptible to GI upset as a result of nitrate supplementation, so it should be tested in training prior to using it in racing.
  
  As with caffeine, there appears to be an upper limit to the benefits of consumption - more is not always better. Going from 500mg to 1000mg, performance improvements don't change.
  
  Performance gains are harder to achieve in highly trained athletes. 
• If you are going to supplement from nitrate, I would say make sure you are getting nitrate in the right amount. 
  
  Just buying beetroot juice from the grocery store isn't great because the variation in nitrate concentration is massive. 
  
  There's a paper called: What's in Your Beet Juice? Nitrate and Nitrite Content of Beet Juice Products Marketed to Athletes which shows that even in products marketed specifically to athletes, the variation is massive. 
• One good product that was discussed in the Andy Jones episode is called Beet It - it's the one I use and contains 400mg per shot of nitrate which is right in the sweet spot of what you need. 

Beta Alanine

• Beta Alanine augments intracellular buffering capacity, having potential beneficial effects on sustained high intensity exercise performance. 
• For triathlon purposes, this doesn't seem that beneficial as it has effects on durations of 30 seconds - 10 minutes. 
  
  If this is interesting to you, have a look at the paper and particularly table number three. 
• There is the argument that if you do high intensity exercise you may want to supplement specifically for that exercise to do slightly better in training and possibly get better adaptations. 
  
  However, I don't think it's something that's ever been proved to work, and you could equally supplement with something like caffeine for this purpose too. 
• I think triathletes and coaches would be using this more if it was particularly beneficial in triathlon, but we know they're not at present. 

Sodium bicarbonate

• The same applies as above with beta alanine. It's beneficial for short durations so not as relevant to triathlon. 
• It's similar to beta alanine in that it increase buffering capacity, but it's extracellular rather than intracellular. 

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• There are a lot of supplements that claim to enhance performance indirectly by supporting athletes health, body composition and ability to train hard and recover quickly, adapt better, tolerate pain etc. 
• Reviews have noted that there's a low quality in studies that support these supplements that claim to support immunity for example. 
  
  These issues are things like small sample sizes, poor controls and unclear procedures for randomisation. 
  
  Therefore, there are not many supplements that have actually been shown to be beneficial indirectly. 
• In the paper, these are in table four, five and six. 

Supplements for immune support

• These are in table four in the paper. 
• The review notes that the most promising candidates to assist in the prevention or treatment of immune function, particularly upper respiratory symptoms, are vitamin D and probiotics. 
• Vitamin C may be beneficial for prevention during periods of heavy exertion. 
• Zinc may be beneficial at the onset of symptoms. 
• Probiotics have the additional benefit of reducing the incidence of travellers diarrhoea and gastrointestinal infection. 
• The evidence for efficacy of vitamin D and probiotics is moderate. The outcome measure used is preventing or treating upper respiratory symptoms. 
• Vitamin C has moderate support for preventing upper respiratory symptoms, but no support for actually treating it. 
• Zinc has no support for prevention, but has moderate support for treating upper respiratory symptoms IF you start the consumption within less than 24 hours of the symptom onset. 
• There is a long list of things that have low support, including bovine colostrum, polyphenols. 
• Those with limited support include glutamine, caffeine, echinacea, omega-3. 
• Finally in no support they mention vitamin E and beta glucan, 

Supplements to assist training harder, faster recovery and injury prevention/accelerated return

• These are in table five in the paper. 
• The supplements that look like they have the most positive effects for endurance athletes are vitamin D and certain anti-inflammatory supplements. 
• Vitamin D has pretty good evidence for enhanced adaptive response to stressful exercise. 
  
  If you are deficient in vitamin D you may also be a greater risk of stress fractures, so supplementation may reduce this risk. 
• Anti-inflammatories, such as curcumine (found in tumeric), has some evidence supporting it for decreasing inflammation and indirect markers of muscle damage.
• Another supplement with proven anti-inflammatory benefits is tart cherry juice. 
• Anti-inflammatory effects may be beneficial but it really depends on the context. 
  
  It may also blunt the adaptive response to exercise, especially if these supplements are consumed immediately after training so it may be better to wait a while. 
• It's difficult to say whether having less inflammatory markers is actually a good thing. 
• Personally I don't use anti-inflammatory supplements, and I'm not really tempted to start after reading this review. 
• Beta hydroxy beta methylbutyrate is also noted as the benefits are indirect but seem more promising for strength and power athletes rather than endurance athletes. 
• Omega-3 supplements and creatine have some indirect benefits for certain athletes, but again not that relevant for endurance athletes. 

Supplements to promote and assist gaining lean muscle mass, or loss of body fat mass

• Protein has consistently been found as something that can increase lean muscle mass. 
  
  For some triathletes and endurance athletes may need to work on this, particularly those from a running background who are really lean and may need to bulk up a little. 
  
  This does need to be combined with some resistance training, not letting all the endurance training tear down the potential effects of the muscle gains you're looking for. 
• Leucine is listed but doesn't have any efficacy evidence that's really reliable so far. 
• When it comes to losing fat mass, none of the things listed in the article seem to have an effect other than protein. 
  
  These include omega-3 and green tea.
• Protein can have a small but significant effect of losing fat mass when you supplement with that. 

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• For direct benefits for triathletes you have caffeine and nitrate. 
• For indirect benefits relating to keeping healthy, you've got vitamin D and probiotics to reduce the risk of upper respiratory symptoms. 
  
  For keeping healthy in terms of injuries, you have vitamin D to reduce the risk of stress fractures, and anti-inflammatory supplements to recover better. 
• If you want to improve your lean muscle mass, protein is a good one. 
• Some supplements that are worth taking if you have a proven deficiency are vitamin D, iron and calcium. 
• There are a large number of things recommended to provide practical energy when needed. 
  
  When you're training for example, or finishing a session, sports nutrition products like sports drinks, gels, bloks, protein sports bars ect can be used. 

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• This is relevant for all age-groupers and professional athletes, particularly faster age-groupers. 
• Many athletes consider supplements to be safe, and there can be some discrepancies in the list of prohibited substances on the WADA website, and what they are called on supplement labels. 
  
  This can make it difficult to recognise whether you are consuming a prohibited substance.
• Most concerningly, there is a real risk that a supplement may contain a prohibited substance as an undeclared ingredient or a contaminant. 
• This study: Australian Supplements Survey Highlights Need for Testing reported that 15% of more than 600 supplement products contained undeclared banned substances. 
• These banned substances have been found in very common supplements such as vitamin C and multivitamins and minerals. 
  
  This is rare compared to a pre-workout supplement for example, but it's worth keeping in mind. 
• There are efforts being made to address these problems, which include the use of third party auditing activities to identify products that athletes may consider to be at low risk of containing prohibited substances. 
  
  They're not an absolute guarantee but it's the best we currently have. 
• One of the authorities that does this third party testing is ​Informed-Sport. 
  ​
  This is a global quality assurance programme for sports nutrition products. 
  ​
  This programme certifies a product not just once, but every batch of it, and the raw materials used in it. 
• Personally I made sure that all the supplements I use are on the Informed-Sport list of trusted brands. 
• These include:
  
  - Science in Sport for things like gels, sports, drinks and caffeine shots. 
  - Precision Hydration for electrolyte products. 
  - Beet It for nitrate. 
  - Bulk Powders for whey protein.