Monday, 22 August 2011
International Sport Science Sports Medicine Conference 2011, Newcastle, UK
I recently attended the ISSSM conference hosted by Northumbria University in Newcastle. It was busy schedule over the 3 days and there were some fantastic speakers. Below is a summary of the key ‘novel’ research in sports science.
Working with Athletes
Several of the speakers talked about working with elite athletes. The most important characteristics a practitioner should have are as follows:
· Knowledge of the sport as well as discipline specific knowledge
· Show that you care
· Emotional Intelligence
· Extrovert Personality
From my own experience I agree with most of those. As practitioners we have to be like chameleons and have the ability to adapt to the environment. The way you work with a triathlete is very different from how you would approach working in Premiership football, however, as long as you show passion and that you care about the athlete’s wellbeing, they will welcome your support.
IOC Consensus on Sports Nutrition
Professor Ron Maughan along with Professor Louise Burke and Dr Stuart Phillips delivered an excellent session on the new IOC consensus on sports nutrition.
In terms of Carbohydrate:
· Although there is some evidence regarding increased adaptations to endurance training of training on low carbohydrate stores and competing with high carbohydrate stores more research is needed. Chronic training with low carbohydrate stores does increase the susceptibility of getting more illnesses and does reduce the quality of the high intensity sessions. It may be better to do the easier sessions fasted but the harder ones after carbohydrate feedings.
· Rinsing a carbohydrate drink in the mouth without ingesting it has shown some exciting performance benefits but only the studies that have investigated this in a fasted state have found benefits. Studies that looked into this 3 hours after a meal found no performance benefits. There seems to be an activation period of the carbohydrate receptors in the mouth.
· For athletes competing in sports lasting longer than a few hours will benefit from multiple transportable carbohydrates i.e. glucose and fructose in a ratio of 2:1. Having this type of mix allows greater amounts of carbohydrate of up to 90 g/h to be absorbed by the gut.
In terms of Protein:
· Dr Stuart Phillips presented some interesting data on protein feedings. Consuming any more than around 25 g of protein per feeding is not necessary even for larger and heavier athletes. Eating protein over upper limits (i.e. 2 g/kg) may not offer any benefits to athletes. I’m not sure I personally agree with this. Kevin Tipton has shown with some of his studies that protein intakes higher than this during periods of intense training can offer more benefits. Read the abstract here.
· Milk was discussed as being an excellent source of protein. I agree with this and we should encourage athletes to consume 2-3 milk/yogurt servings per day, particularly after training.
Vitamin D and the Athlete
There is some emerging evidence that vitamin D is an important vitamin for the athlete. Insufficient vitamin D can impair the immune system, it can be detrimental to bone health and can have negative effects on performance. Several studies have shown that more athletes than previously believed have either vitamin D deficiency or insufficiency. For an athlete who competes in an impact based sport, it is important that they correct and insufficiencies. Athletes with darker skin may be at increased risk as well as athletes that compete indoors. Vitamin D should be regularly screened and any deficiencies should be corrected.
The most controversial session was delivered by Dr Eric Goulet on hydration in athletes. There is already a great deal of controversy on this topic. Some researchers believe that even a 1% dehydration can impair performance whereas others believe that it is down to the brain and thirst regulation. Dr Goulet presented some really exciting data on the limitations of the current research on dehydration. In a nutshell, most of the studies have looked at the effects of dehydration on exhaustion type protocols (i.e. exercise at 70% of VO2max until you can no longer continue). The problem with this is that no sports require this type of exercise. Time trials are a more valid and reliable performance measure and very few studies have investigated the effects of dehydration on real-world type performance.
In addition, whether the effect of dehydration in women is similar to that of men is unknown as majority of the participants used in this research have been male. Similarly, the effects of dehydration on running is not clear as most of the research has looked at cycling. We also don’t know what effect dehydration has on performance when competing at temperatures of 23-28 degrees Celsius as most of the research has looked at temperatures either above or below these values.
I found this one of the most interesting presentations as we still have much to learn about dehydration and performance. I personally believe that when not competing in extreme heat, a 2% dehydration will not impair endurance performance. Whether this level of dehydration has an effect on sports that include decision making such as team sports we just don’t know.
In the meantime I am really exciting to get my teeth stuck into this paper: Effect of exercise-induced dehydration on time-trial exercise performance: a meta-analysis.
Dietary Nitrate Supplementation
By far the best talk given throughout the conference was by Professor Andy Jones who has over the past few years published a lot of work in the area of dietary nitrate (mainly beetroot juice) and endurance performance. Here is a summary of the main points:
· 500 mL of beetroot juice consumed over 1-7 days reduces the oxygen cost of exercise. Similarly, it also reduces the ATP cost of anaerobic exercise.
· It is definitely the nitrate that is responsible for this, as beetroot juice that has had the nitrate removed, did not show these positive effects.
· Beetroot juice also enhances time trial performance over a 10-mile time trial. Power output is increased and oxygen uptake is reduced indicating that the energy must be coming from another source.
· The mechanisms are still unclear as to where this energy is coming from as data from Sweden conflicts from data published here in the UK.
· The nitrate literature is an extremely exciting area and will continue to be. When more papers are published on this I will probably write a blog on this on its own.
· In summary, 500 mL of beetroot juice taken for 1-15 days appears to be beneficial for reducing blood pressure and reducing the oxygen cost of exercise. More research is needed to elucidate whether these effects are observed in performance tests.