(Image: Jonny Gawler)
In the latest issue of 220 Triathlon (on sale from 4 Feb), we speak to the head of the Gatorade Sports Science Institute UK, Dr James Carter, in our Fuelling your Peak Performance feature.
Here he shares his essential guide to what to eat and when throughout a sprint-, Olympic-, middle- and long-distance triathlon.
For our 18-page performance nutrition special, pick up a copy of the March issue of 220 Triathlon, on sale from 4 February. To access the magazine digitally, click here.
To optimise performance come race day, practising a race-day nutrition strategy consistently in training to maximise fluid and fuel replacement is crucial. This will help the athlete discover their individual tolerances (amount, types, flavours etc), but will also give them a chance to adapt over time e.g. an athlete may be able to train their gut to tolerate and absorb higher amounts of carbohydrate and fluid through training their nutrition.
1 Fluid before: Monitoring urine colour, frequency and volume can help guide an athlete on his or her hydration status. If an athlete is frequently going to the toilet and notices pale coloured urine and large volumes, this can provide reassurance that further fluid consumption may not be required. If, with two hours to go until race start, the athlete still has dark coloured urine and in small amounts, drinking a further 2-3ml per kilogram (kg) body mass (bm) would be recommended over the next 30-45mins. This would then still leave time for any further urine to be expelled before the start of the race.
2 Fluid during: With exercise lasting beyond 90mins there becomes greater emphasis on the athlete trying to minimise fluid losses i.e. maintain body mass within 2-3% of starting mass. This goal becomes more challenging with higher sweat rates and increased exercise intensities; therefore, the athlete must use training to develop a personal hydration strategy that aims to balance fluid replacement, carbohydrate delivery and the avoidance of over drinking. Habitually recording body mass before and after training to determine typical sweat rates in a range of environmental conditions will then allow the athlete to develop this personalised hydration strategy.
3 Carbohydrate during: Where a range is provided, the expected race duration, as well as individual tolerances, can help guide the athlete as to where on the spectrum they should be aiming.
4 Fluid after: The amount of fluid to replace will depend largely on the athlete’s sweat loss and their fluid replacement during exercise, which are both highly individual. As a result, it would be beneficial for the athlete to monitor their losses during exercise, with the post exercise aim being to replace about 125-150% of this loss (in order to compensate for additional sweating and urine loss that will occur post race) gradually in the hours after exercise. Drinks should contain sodium in order to replace that lost in sweat, but also to help drive fluid uptake and retention. As such, sports drinks are often seen as a good solution after exercise because they typically contain fluid, sodium and carbohydrate and can help kick-start the recovery process.
5 Carbohydrate after: If subsequent days of exercise are planned and/or to optimise glycogen replenishment, this routine should be continued each hour until regular meals commence.
Protein: While the ingestion of protein during exercise is not associated with improved performance, there is some evidence to suggest that the intake of a small amount (20g) of protein either before or during prolonged exercise (> 3hrs) may help the muscle reconditioning process.
Caffeine: There is evidence that caffeine can improve endurance exercise performance, with 2-3mg of caffeine per kg bm shown to be effective. As a result, some adult athletes do ingest caffeine-containing products 45-60mins before and/or during exercise. As with all sports nutrition, athletes wishing to experiment with caffeine should first do so in training to determine individual preferences and tolerances and they should also be aware of the side effects, which can include: anxiety, accelerated heart rate, gastro-intestinal distress and impaired sleep. For those wishing to learn more about caffeine and exercise, the following resource is recommended: http://www.ausport.gov.au/ais/nutrition/supplements/group_a
1.Cox, GR et al. (2010). Daily training with high carbohydrate availability increases exogenous carbohydrate oxidation during endurance cycling. Journal of Applied Physiology: 109; 126-134.
2.Jeukendrup, AE (2011). Nutrition for endurance sports: Marathon, triathlon, and road cycling. Journal of Sports Sciences: 29(S1); S91-99.
3.Phillips, S and Van Loon, L (2011). Dietary protein for athletes: from requirement to optimum adaptation. Journal of Sports Sciences: 29(S1); S29-S38.
4.Shirreffs, S and Sawka, M (2011). Fluid and electrolyte needs for training, competition, and recovery. Journal of Sports Sciences: 29(S1): S39–S46.
5.Van Loon, L (2013). Is there a need for protein ingestion during exercise? Gatorade Sports Science Institute – Sports Science Exchange: Vol. 26; 109; 1-6.
Contributor: Dr James Carter is Head of the Gatorade Sports Science Institute UK, based at Loughborough University. The Institute works with athletes to optimise their performance and health through research and education in sports nutrition science. For the latest news on sports nutrition, including downloadable sports science exchange articles and video clips from leading experts, visit www.gssiweb.org.