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Dr James Morton

SiS World Class Knowledge Director

Fueling the Tour of California

Read more on the demands of the event, the challenges of heat stress and altitude, hydration and carbohydrate goals and fueling for the time trial.

Demands of the Event

The Tour of California represents a 7-day stage race beginning in Sacramento on Sunday 14th May and ending in Pasadena on Saturday 20th May. The race will consist of approximately 950 km raced over 2 mountain top finish stages, 1 mountain descent stage, 3 flat stages and 1 time trial. Whilst the race may appear shorter than other stage races, the shorter stages will often present as more intense racing. Additionally, although the time trial on stage 6 will only be raced over 24 km, it takes place at 2000 m above sea level! When considered together, the Tour of California will provide an exciting 7 days of racing!

Challenge of Heat Stress and Altitude

By far the biggest challenge in California will be the higher ambient temperatures than that which has recently been experienced in other World Tour races in Europe. Indeed, we can expect temperatures in excess of 85 F, very different from the rain and snow in the Tour of Romandie! In non-acclimatized riders, such heat stress carries the obvious risk of dehydration which can increase riders’ heart rate, ratings of perceived exertion and even increase the rate that our muscles use carbohydrate as a fuel (1,2). Furthermore, exercise at altitude also increases carbohydrate use (3) and hence the combined demands of heat stress and altitude will ensure this race will present as a significant nutritional challenge!

Hydration Goals

Riders will be following an individualized hydration strategy that aims to avoid dehydration greater than 3% body mass loss. In practice, riders will be aiming to drink at least 500 ml of an SiS GO Electrolyte per hour though this can often increase to 1 L per hour in conditions like California. All drinks will be maintained at a “cold” temperature in an attempt to reduce the rate of increase in core temperature during exercise and attenuate the negative effects of heat stress. Perhaps more importantly is actually beginning the race in an appropriately hydrated condition. In this regard, it is essential that riders consume at least 500 ml to 1 L of SiS GO Hydro at breakfast, usually consumed 3-4 hours before the stage commences (4). The electrolytes (especially sodium) help to stimulate thirst and retain fluid before and during the stage. Additionally, riders will weigh themselves before and after each stage to provide a simple measure of fluid loss and therefore inform the post-stage hydration strategy. In general, 1.5 L of fluid should be consumed for every 1 kg of body mass loss during the stage.

Carbohydrate Goals

Given the effects of heat stress and altitude on increasing carbohydrate usage, it is crucial that riders adhere to the basic principle of consuming daily carbohydrate at a rate of 8-12 g/kg body mass. From a fueling on the bike perspective, this means adhering to 90 grams per hour via a mixture of carbohydrate-electrolyte drinks, solid foods and energy gels (5). SiS Electrolyte gels are especially useful on hot stages as they simultaneously deliver 20 grams of carbohydrate per gel and additional sodium, whilst also remaining easy to digest and tolerate. Simultaneously adhering to hydration strategies and feeding 90 grams per hour will help to reduce the negative effects of heat stress on cardiovascular strain and maintain carbohydrate availability such that higher power outputs can be achieved.

Fueling the Time-Trial

The time trial on Stage 6 will be raced at 2000 m above sea level and will be a “full gas” effort that will really challenge the riders. Whilst fueling the evening before and pre-race meal and hydration are important, the use of pre-cooling (via ice slushies) 10-15 minutes before the warm up may also be required to lower pre-race body temperature (6). Riders will also consume additional carbohydrate during the warm-up in the form of an electrolyte gel as well as 2-3 mg/kg of caffeine at a relevant point during the warm up (7). In order to prepare for time trials, riders will also have previously loaded with beta-alanine and consume sodium bicarbonate (8) around 90 minutes prior to going down the ramp. Hopefully, after this stage Team Sky will be leading the race!

1. Febbraio M (2001).Alterations in energy metabolism during exercise and heat stress. Sports Med 31(1):47-59
2. Galloway, SD and Maughan, RJ (1997) Effects of ambient temperature on the capacity to perform prolonged cycle exercise in man. Med Sci Sports Exerc. 29:1240-9.
3. Parolin M et al. (2000). Regulation of glycogen phosphorylase and PDH during exercise in human skeletal muscle during hypoxia. Am J Physiol Endocrinol Metab, 27:E522-34.
4. Thomas, DT et al (2016). American College of Sports Medicine Joint Position Statement. Nutrition and Athletic Performance. Med Sci Sports Exerc. 48:543-68.
5. Stellingwerff T et al (2007) Carbohydrate supplementation during prolonged cycling exercise spares muscle glycogen but does not affect intramyocellular lipid use. Pflugers Arch. 454:635-47.
6. Ross M et al. (2013). Precooling methods and their effects on athletic performance : a systematic review and practical applications. Sports Med 43(3):207-25
7. Talanian, JL and Spriet, LL (2016). Low and moderate doses of caffeine late in exercise improve performance in trained cyclists. Appl Physiol Nutr Metab 41:850-855.
8. Sale C et al. (2011). Effect of β-alanine plus sodium bicarbonate on high-intensity cycling capacity. Med Sci Sports Exerc 43:1972-78.

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