This is part one of two posts covering the conference. The second part will be released next week.
Last week the Netherlands sporting collaboration, TeamNL, presented the Leaders in Performance Conference with the focus on sports nutrition. I learned about the conference from Asker Jeukendrup's twitter feed. I wanted to attend as I am particularly interested in this topic and also I was impressed with the list of speakers. I wasn't able to go in person, however, the conference was also available to follow via a live webstream where I could listen to the different speakers and see their presentations.
These are my notes from the first three presentations. There was a lot of valuable information shared and this is not a comprehensive review of everything in each presentation. I've noted the things that were most interesting to me and which I think I can implement in my own training and for the athletes I coach.
If you would like to see the presentations in full and also have access to the handouts and other resources they are available on mysportscienceacademy.com. I've found this platform very useful as I was able to go through the presentations again and capture any points I missed. There will also be future presentations and courses available that I'll be looking out for.
Fueling the Brain - Dr Romain Meeusen
Human Physiology and Sports Physiotherapy Research Group Vrije Universiteit Brussels
Meeusen's talk focused on the brain and the interaction between nutrients and brain function. It was a fascinating presentation that provided a holistic picture of all the potential impacts, means of manipulation and long-term benefits that nutrition can have on brain function. Meeusen's presentation relied on his extensive research which I would highly recommend reading further: a list of all of his published research is avaiable on PubMed. The following are my notes from the presentation and the points I found most interesting.
- To make decisions the brain keeps track of nutrient availability
- there are sensors (chemosensors) in the mouth, stomach, pancreas and bowel
- these different sensors provide signals to areas in the brain triggering cues which include reward, taste, motivation, and food-seeking behavior.
- An example of a chemosensor and its impact on the brain can be seen through a carbohydrate (CHO) mouth rinse experiment
- after a 10" mouth rinse with a CHO solution, performance (in this case power output) was found to increase in exercises of duration of 45-60'
- this was measured by MRI and EEG which showed that stimulation in the brain in reaction to the mouth rinse.
- The brain needs fuel and its preferred source of fuel is glucose
- 130g/day of glucose is required at rest
- this is a high percent of the available glucose in the body
- during exercise muscle glycogen is depleted at a greater rate than brain glycogen stores
- like the muscles, supercompensation takes place for brain glycogen stores
- the brain can use other fuels such as ketones, although this may not actually be the preferred fuel.
- Can the brain be manipulated?
- there are some substances that may help with fatigue and brain stimulation
- tyrosine appears to help in extreme situations such as sleep deprivation or starvation
- caffeine has a proven record of being very effective in stimulating the brain and reducing fatigue.
- Polyphenols are good for the brain and help prevent cognitive decline with age:
- non-flavonoid sources include: blueberries, kiwis, plums, apples, grapes, wine
- flavonoid sources include: parsley, celery, green tea, red wine, chocolate, citrus fruits.
My summary and practical steps
- The brain and the body are intimately linked and the presence or lack of nutrition is communicated to the brain even if we're not necessarily aware of it.
- Sensors in the body allow for faster reaction to fuel intake than the fuel can actually be processed by the intestinal tract. While a CHO mouth rinse can be used in the last hour of an event when an athlete is struggling to ingest fuels, it may also make sense to rinse the mouth prior to ingesting nutrition at other points during a race.
- Caffeine is effective and needs to be used wisely during events.
- Eating foods high in polyphenols is vital to prevent cognitive decline.
Carbohydrate Recommendations for Performance - Dr Asker Jeukendrup
Professor and Performance Manager Nutrition TeamNL Loughborough University
Jeukendrup explained the various carbohydrate recommendations and the process that has he has been through to help some of the best athletes in the world achieve their best performances. He has shared many incredible resources on his website which is one of the most practical, insightful, and useful websites covering performance nutrition: MySportScience. His presentation and all of the data on his website is based on his own thorough and extensive research that is also available on PubMed. In my notes I've tried to capture the most practical and useful points that I can immediately.
- There are multiple different sets of CHO recommendations with the basic tenants being
- ingest 1.2g/kg of CHO every hour for 4hrs after exercise
- replenish glycogen stores quickly after exercise
- 7-12g/kg of CHO are required on hard days (7g=~3hrs; 12g=~5hrs training).
- While these are good guidelines the application is more complicated than that
- it is critical to consider the whole 24hr period and where the training falls within that period
- it is important to know how much recovery time is available and when the next session is
- for ever 1g of glycogen 3g of water are stored so there is an impact on athlete weight which may need consideration.
- The key issue that an athlete faces is meeting the demands of performance with a CHO supply
- the muscles store 400-900g of glycogen and the liver stores 60-90g
- during exercise the body uses 60-350g/hr
- clearly the supply of exogenous CHO is critical for longer duration events as the endogenous supplies will not meet the demand.
- Multiple studies have shown CHO intake leads to improved performance.
- The limiting factor for CHO intake is not the muscles or gastric intake, but absorption in the intestine.
- Mixing CHO sources allows for the greatest rate of absorption:
- the GLUT1 transporter works with glucose, while the GLUT5 transport works with fructose
- a 2:1 glucose:fructose mix appears to be optimal blend for sports nutrition
- while some people report having stomach issues with fructose, it is not that common and is not shown in the studies
- the highest rate of absorption appears to be 1.5g/min or 90g/hour (for the mixed CHO source)
- Chrissie Wellington achieved 86g/hr during her 2009 Ironman Hawaii victory
- multiple athletes have achieved an intake of 86-88g/hr.
- Recommendations for CHO intake are:
- 0-60': nothing, or CHO mouth rinse
- 60-120': 30g/hr
- 120'180': 60g/hr
- 150'+ : 90g/hr.
- The source (drink, gel, bar) doesn't appear to matter so whichever works best for an athlete is what they should use.
- The final step is to build a plan that incorporates the fluid and CHO guidelines
- Asker has created a useful tool for athletes to determine what they need for a specific event: CORE nutrition planning.
My summary and practical steps
- It is very clear that CHO intake improves performance and that a CHO fueling plan is critical for endurance athletes.
- Finding the right source that works for each athlete is vital to achieve the 90g/hr rate.
- CORE provides complete plans that put into practice all of these guidelines - I would highly recommend checking this out.
Training low: does it really work? - Dr John Hawley
Exercise and Nutrition Research Program at the Mary MacKillop Institute for Health Research Australian Catholic University
Hawley's presentation was clear, concise and perfectly showed the scientific backing for training in a low glycogen state. I found the flow of the presentation, the focus on relevent studies and the practical guidelines to be extremely informative and it made the research he shared understandable and useful for me. He mentioned a few studies in his presentation which are linked and also relied on his own extensive research also available on PubMed. I tried to capture everything I could in my notes, but I would recommend following the links and digging deeper into his work as it is fascinating.
- There are multiple low-carbohydrate diets that are very popular in the media, yet the presentation was not about that, but rather about periodised nutrition.
- The primary goals of periodised nutrition are:
- to provide support to optimise training adaptation
- to underpin optimal recovery strategies
- to assist in optimising physique for event requirements
- to adopt evidence based recommendations.
- There are different factors that can be manipulated to impact training adaptation
- the metabolic load can be adjusted by changing the availability of glycogen
- the mechanical load can be adjust by changing training, heat and altitude factors.
- Previous recommendation for endurance sports were a one-size fits all approach to CHO needs
- now it's important to match CHO to training demands (from 0 to 12g/kg depending on the training duration).
- Training and diet interventions have effects on glycogen concentration
- even exhausted there is still some glycogen available in the body and brain
- as a result of their training, athletes have greater stores of glycogen.
- Multiple studies show the benefit of train low:
- Hansen A.K. study - significant increase in endurance for low glycogen intervention over 10 weeks
- Yeo W.K. study - commencing half the training sessions in low glycogen state led to better training adaptations
- Psilander N. study - commencing exercise with low glycogen concentration increases PGC-1alpha mRNA in skeletal muscle.
- Refueling the muscle with CHO decreases gene expression so it's better not to refuel
- however, this impacts the ability to achieve a high training quality
- the solution is to train high, sleep low with a protocol such as the following:
- replete muscle glycogen stores (at lunch time / early afternoon)
- train high = high intensity training (PM training session)
- eat a low CHO meal for dinner
- sleep low = low glycogen stores after depletion during afternoon training session
- train low = fasted prolonged low-intensity training (AM training session).
- "Train high, sleep low" protocols have shown up to 3% improvement in performance.
UPDATE: Thanks to Dr Hawley for providing a free download for some of the research that his presentation was based on. Here is his paper on Maximizing Cellular Adaptation to Endurance Exercise in Skeletal Muscle.
My summary and practical steps
- Periodised nutrition is a more effective way to train that goes beyond simple daily CHO recommendations.
- Training in a state of low glycogen can have significant impacts on performance, but comes at the cost of individual session quality.
- A "train high, sleep low" protocol allows athletes to achieve the benefits of training high while also getting the metabolic benefits of low glycogen training sessions.
I've found that these speakers share a great deal of fantastic material on twitter. They often share links and studies that provide valuable insight into sports nutrition. If you're interested following them, you can find all of them on my LPCNutrition twitter list.
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