Caffeine & Endurance Exercise

1,3,7-trimethylxanthine, although you may not have heard it called that before, I can almost guarantee that it is your favourite stimulant. For most of us not a day goes by without a dose of caffeine, usually in the form of tea, coffee, chocolate, coca cola and the seemingly ever increasing number of energy drinks. Ever since caffeine was taken off WADA’s banned list in 2004 you have been able to find more and more sports nutrition products that contain caffeine, in fact, it’s actually quite difficult to find gels and tablets that don’t contain caffeine.

The efficacy of caffeine for the use in sport, especially endurance sport is well established and widely used by athletes, so much so that WADA have placed caffeine on to their “watch list” for 2016. Which means they are concerned that it may be being overused or abused during competition and so they want to keep an eye on it. The Australian Institute of Sport place caffeine in category A of their supplement list¹ which means that there is sound evidence for a performance improvement. This post will not be concerned with whether caffeine works or not because we know it does. With this post I hope to clear up some of the other questions that surround the use of caffeine as a sports supplement.

How much to take and when to take it

As with many supplements there is always a trend towards the thinking of “more is better”, however in reality there is always a point where more no longer becomes better and soon becomes unpleasant. The earlier caffeine studies showed that a dose of around 6mg/kg of body weight had a positive effect on an 1hrs cycling performance. That is the equivalent of around 300-500mg of caffeine (a lot!), however, it soon became apparent that equally positive results were found with smaller doses of caffeine, ~200mg. And so it was concluded that caffeine does in fact improve performance but it appears only to be dose dependant up to a point, and then further ingestion of caffeine does not result in further improvements^2,3.

Recently on his website⁴ Asker Jeukendrup reviewed a paper that looked at caffeine and longer duration cycling. Subjects rode for 2 and a half hours and then performed a time trial. Subjects either ingested 100mg caffeine, 200mg caffeine or a placebo 40 minutes before the time trial. Subjects who ingested the 200mg performed the TT quickest followed by 100mg.  

So the take home message is that if you have an event/training session that will last around an hour then around 200mg of caffeine an hour before your event will do the trick. Or if you are going on a longer ride and want a pick me up for the final climb or last hour of riding then take your 200mg caffeine either 40mins – hour before that climb or last bit of riding.

Source of caffeine

I’ve said this before but a classic error of dietitians and exercise coaches is to talk in terms of weights and nutrients but not in a way that most people understand. What does 200mg of caffeine look like? One coffee? Ten? Below is a table ^2,3,5 with the caffeine content of several drinks and sports nutrition products to give you an idea of what 200mg would look like.

Product	Serving size	Amount of caffeine mg
Coffee percolated (Italian coffee maker)	150mls (about halfway up of a normal coffee mug without milk)	65-125
Coffee espresso	1 espresso	~100
Coffee instant	150mls	40-100
Tea	150mls (black)	10 -50 depending on length of time you leave the bag in the cup
Chocolate bar	100g	15
Coca Cola	Can (330mls)	46
Red Bull	Can (250mls)	80
Monster	Can (553mls)	176 (plus a bucket load of sugar)
Science in Sport GO Hydro+caffeine tablets	One tablet (4.5g)	75
Science in Sport GO Caffiene Gels	One gel 60mls	75
Overstims Cafein’Gel	One gel (29g)	75

There is also the question of whether coffee is as effective as a specific caffeine containing sport product. Sports nutrition companies would obviously argue that it is not and would encourage you to use their products instead. However, coffee has been shown to be as effective⁷ as a caffeine containing sports drink in a cycling time trial. Obviously coffee during a ride or run is not particularly practical, unless you don’t mind stopping at a café. So I would recommend gels or drinks during the event but if you want and early caffeine boost during your training session than it appears a strong coffee will not only be a lot nicer than a gel or sports drink but will also be as effective.

How does it work

In the early studies involving caffeine the benefits were thought to be because caffeine increased fat utilisation during exercise and thus reduced glycogen utilisation enhancing endurance performance². However due to more recent evidence the current explanation is that caffeine reduces perception of fatigue and allows people to maintain a higher intensity for a longer period of time⁶

Caffeine and recovery 

When thinking about caffeine and recovery an obvious issue is sleep. Sleep is essential to performance and poor sleep can lead to several problems, most importantly for sports people are, reduced training capacity and impaired immune function. This may sound like an obvious point but as most of us amateur athletes have to fit our training around our lives, (jobs, family etc.) a lot of us train in the evening. As caffeine can take from 3 – 6 hours to clear the blood stream⁸ it is not recommended that you use caffeine for a training session in the evening.

Interestingly there is some data that suggests that post exercise caffeine ingestion may reduce perceived leg pain after a long cycling event⁹. I would say we need more research before we can confidently recommend caffeine after exercise, however, if you are anything like me then a cup of tea or coffee is part of the post ride ritual anyway. 

Does it dehydrate you

The belief that coffee dehydrates you is as old as the hills but is there really any truth in it? As pointed out by the Journal of the International Society of Sports Nutrition in their position stand on caffeine⁸ it is important to separate caffeine consumption at rest (in the office for example) and caffeine consumption during exercise. While there may be some evidence that caffeine can increase urinary output at rest, this is not the case for during exercise⁸.

The bottom line is if you maintain appropriate hydration levels both at rest and during exercise then caffeine consumption will not lead to you being dehydrated.   

So in conclusion

• Around 200mg of caffeine taken 45-60mins before the effects are needed
• Can be in the form of coffee/drinks/gel/tablet
• Does not hinder recovery but caution is needed when taking before planning to sleep
• Does not dehydrate you 

For more information on caffeine, supplements or our sports nutrition packages please contact us on info@gabinetederueda.es or via Twitter @DieteticodRB and Facebook @GabinetedeRuedaBradley

References 

1.  http://www.ausport.gov.au/ais/nutrition/supplements/groupa
2.  Burke, L, 2007. Practical Sports Nutrition, Human Kinetics
3.  Jeukendrup, A; Gleeson, M; 2004. Sport Nutrition, Human Kinetics
4.   http://www.mysportscience.com/single-post/2016/08/02/Timing-of-caffeine-intake-in-long-races
5.  http://energydrink-es.redbull.com/cafeina-en-red-bull , http://www.scienceinsport.com/ , https://www.overstims.com/int_index.php?lang=eng
6.  American College of Sports Medicine, 2016, Nutrition and Athletic Performance, available at http://www.acsm.org/public-information/position-stands
7.  Hodgson, A, B et al. 2013, The metabolic and performance effects of caffeine compared to coffee during endurance exercise, PlosONE , 8, 4
8.  Goldstein et al. 2010, International society of sports nutrition position stand: Caffeine and performance, Journal of the International Society of Sports Nutrition, 7, 5  
9.  Caldwell, A; et al. (2015) "EFFECT OF CAFFEINE ON RECOVERY FROM AN ENDURANCE CYCLING EVENT," International Journal of Exercise Science: Conference Proceedings: Vol. 11: Iss. 3, Article 39. 

A post exercise recovery meal high in protein

Following on from our post on the benefits of adding protein to your post-workout meal we thought it would be helpful to give a few examples of some meals that would provide a good dose of protein. 

In the world of sports nutrition, it is easy to get carried away with discussing what nutrients are important for pre/post exercise and to forget that we don’t actually eat nutrients as such, we eat food! We don’t go to the supermarket and say “ok we’re running low on protein and vitamin A so we need to buy some”. When we offer advice to somebody about what they should eat post-exercise saying “you need 20g of protein” isn’t much use at all unless your client has a pretty good understanding of nutrition. So with that in mind we provide 1 quick high protein meal paying particular attention to the amino acid Leucine.

Leucine is one of the branched-chain amino acids (BCAAS) and is involved in muscle
protein synthesis (1) which after a hard session is exactly what you need.

For our recipes we recommend organic, free range, and sustainable where possible.

Eggs with artichokes and tomato

Eggs are probably the quickest, easiest and therefore the best post exercise food. Each egg will give you around 6g protein and 544mg of leucine. This recipe is still pretty quick and is a good alternative to just a plain old omelette.

Ingredients (serves 4)

• 2 tablespoons olive oil
• 100g pancetta chopped
• 1 red onion sliced
• 2 x 400g tins chopped tomatoes
• 280g jar of artichoke heartsquartered
• 8 eggs
• ½ teaspoon dried chilli flakes
• Handful parsley chopped

Place large frying pan over a medium – high heat. Add the oil and pancetta and cook for 4-5minutes until browned. Add the onion and cook for a further 4-5 minutes. 

Add the tomatoes, season with sea salt and ground black pepper and cook for around 10 minutes. Add the artichokes and mix, reduce the heat to med-low.

Make 8 divots in the tomato mixture and crack an egg into each one. Cook for 4-5 minutes or until the white is coked but the yolk is still soft (if you like your yolks runny). Sprinkle on the dried chilli and parsley, serve.

1. Maughan R., Gleeson M. The biochemical basis of Sports Performance (2004). Oxford University Press.

Receta para la recuperación después del ejercicio

Después de nuestro post sobre la importancia de añadir proteínas a nuestra comida tras entrenar, hemos pensados que sería útil incluir algunos ejemplos de recetas que proporcionan una dosis adecuada de proteínas. 

En el mundo de la nutrición deportiva se habla mucho de qué nutrientes son adecuadas pre y post entrenamiento y es fácil olvidar que en realidad lo que comemos son alimentos completos ¡no nutrientes! No vamos al supermercado pensando “Mmmm, no nos queda mucha proteína ni tampoco Vitamina A ¡tenemos que comprar!”.

Aconsejar a nuestros pacientes/clientes “tomar 20g de proteínas tras el ejercicio” no tiene mucho sentido a no ser que estén familiarizados con el mundo de la nutrición. Así que, con esto en mente, hemos preparado varias recetas para nuestros pacientes deportistas y vamos a compartir una de ellas con vosotros. Son ricas en proteínas y además nos proporcionen el aminoácido Leucina.

La Leucina es un aminoácido ramificado que participa en la síntesis muscular de proteínas (1), lo que es de suma importancia tras una dura sesión de ejercicio.

Huevos con alcachofas y tomate


Los huevos son, probablemente, el alimento más fácil y rápido de hacer y, por tanto, el mejor para después del ejercicio. Cada huevo te proporcionará alrededor de 6 g de proteína y 544mg de leucina. Esta receta es bastante rápida y es una buena alternativa a la tortilla francesa de siempre.

Ingredientes (para 4 personas) 

• 2 cucharadas de aceite de oliva 
• 100 g de panceta picada
• 1 cebolla roja en rodajas 
• 2 x 400 g latas de tomates picados (sin azúcar) 
• 8 huevos 
• 1 tarro de 280 g de corazones de alcachofa en cuartos 
• ½ cucharadita de chile en copos 
• Un puñado de perejil picado 

Coloca una sartén grande a fuego medio - alto. Añade el aceite y la panceta y cocina durante 4-5 minutos hasta que se dore. Añade la cebolla y cocina durante otros 4-5 minutos. Añade los tomates, sazona con sal y pimienta molida y cuece durante unos 10 minutos. Añade las alcachofas y mezcla todo - baja el fuego a medio-bajo.


Haz 8 agujeros en la mezcla de tomate y rompe un huevo en cada uno de ellos. Cocínalo durante 4-5 minutos o hasta que el blanco del huevo se haga pero que la yema esté todavía blandita (si te gustan las yemas así). Espolvorea los copos de chile y el perejil, y a servir.


Referencias

1. Maughan R., Gleeson M. The biochemical basis of Sports Performance (2004). Oxford University Press.

Triglicéridos de cadena media y deporte

Con el aumento en la popularidad de las dietas bajas en carbohidratos y altas en grasa ha vuelto el interés sobre de triglicéridos de cadena media (MCT) para atletas. Debido a que los MCT son absorbidos y oxidados rápidamente se ha argumentado que ambos se pueden usar para reducir la grasa corporal y como fuente de energía durante el ejercicio. Recientemente, una de las figuras más importante en el mundo de la nutrición deportiva, Asker Jeukendrup, escribió un resumen sobre la evidencia disponible sobre MCT y el deporte. El artículo original (que incluye info sobre la función y composición de los MCT) lo podéis encontrar aquí, pero hemos traducido los puntos clave aquí abajo. ¡Te recomendamos que los leas antes de que te compres suplementos de MCT!  

•  Cuando los MCT salen del estómago son absorbidos y oxidados rápidamente
•    La oxidación de los MCT exógenos se mejora cuando son ingeridos con carbohidratos.
•     Ingestión de 30g de MCT no afecta la utilización de glucógeno muscular
•    Contribuyen al gasto energético en un 7% como mucho. Aunque los MCT son oxidados rápidamente no proporcionan mucha energía.
•    La ingesta de más de 30g de MCT causa problemas gastrointestinales.
•    No parece que la ingesta de MCT mejore el rendimiento deportivo. 
•    Sin embargo, es posible que al aumentar ingesta de MCT a costa de los LCT (long-chain triglycerides) de produzca una reducción pequeña en la grasa corporal (pero la evidencia no es muy fuerte).

En conclusión, parece que los MCT no son muy útiles durante el ejercicio, pero es posible que tengan alguna utilidad si se quiere reducir la grasa corporal. Tendremos que esperar a que se realicen más ensayos y pruebas clínicas que apoyen estas declaraciones.

Si quieres saber más sobre suplementación en nutrición deportiva escríbenos a info@gabinetederueda.es

Referencias

1. http://www.mysportscience.com/?reload=true#!MCT-the-new-fuel-for-athletes/cjds/55733b380cf2e4994fb415ea
2. Jeukendrup AE. Modulation of carbohydrate and fat utilization by diet, exercise and environment. Biochem Soc Trans. 2003 Dec;31(Pt 6):1270-3. 

LCHF & Endurance Exercise: Summary of Evidence

It is hard to read about low-carb diets without either getting lost in a world of anecdotes or worse, getting involved in a Twitter fight! There are few topics in the world of nutrition that are so hotly debated. My personal interest in Low Carb - High Fat (LCHF) diets is their application in endurance sport. Finding a way to use more of the 100,000 kcal of fat we have stored in our body is a dream come true. But as with nearly all things nutrition related it just isn't as simple as we'd like!

Before we delve into the evidence I want to point out that I am not looking at LCHF in terms of health, body composition or insulin sensitivity. This is simply looking at whether a LCHF diet will make you a better cyclist/runner/triathlete.

To discuss the current evidence I will be summarising an article by Louise Burke titled "Re-examining High-Fat Diets for Sports Performance: Did We Call the "Nail in the Coffin" Too Soon?" The original article can be found Here. I highly recommend that you read it. 

It is pretty well accepted that a short term (less than 3 days) LCHF diet is detrimental to performance due to the depletion of muscle and liver glycogen without producing an increase in fat oxidation. However following one of these diets over the long term has produced interesting findings. The key questions is, what happens to performance?

After an extensive literature review of studies from 1980 – 2006 the author’s key findings were.

• ·         Exposure to a LCHF diet without ketosis causes key adaptations to the muscle in as little as 5 days. Adaptations include an increase in intramuscular triglyceride (IMTG) stores and an increase in the activity of hormone-sensitive-lipase (HSL) enzyme. This enzyme mobilises triglycerides in muscle and adipose tissue. These adaptations increase the athlete’s ability to oxidise fat.
• ·         These adaptations still persist in the face of 1-3 days of aggressive carb-loading. Although the carb-loading reduces the rate of fat utilisation compared to LCHF alone, they still remain higher than those who follow a high carb diet.
• ·         Exposure to a LCHF diet downregulates carbohydrate utilisation during exercise. Changes in utilisation of muscle glycogen as opposed to blood glucose have been shown to account for this downregulation. This downregulation has been shown to persist in high intensity exercise even in the trials with the carb-load after following a LCHF diet.
• ·         Despite the increased capacity to use this enormous fuel source, fat-adaption strategies do not appear to enhance exercise capacity or performance. Benefits have been limited to protocols of prolonged sub-maximal exercise which do not reflect a true endurance sporting competitive scenario.
• ·         Fat –adaption strategies may impair exercise performance, especially exercise involving shorter high intensity efforts. This is likely due to the impairment of muscle glycogen utilisation.

The author stated that due to the recent boom in the popularity of LCHF she revisited the literature. She found that the sudden re-emergence was not matched by a wealth of new studies that support the use of LCHF for endurance sport. In fact she found only 2 studies on athletes since 2006 and neither showed a performance benefit. They did however show a small but favourable change in body composition through a reduction in body fat.

The author makes the observation that the majority of support for LCHF diets is carried out in the lay and social media and mostly by (and for) non-elite athletes.

She concludes that instead of “black & white” thinking, researchers and practitioners should move towards personalised and individualised approaches when working with athletes.

My Thoughts 

I wanted to give you the take home message from what I think is a balanced view of the LCHF diet and endurance performance. If you want more info on the individual studies that the author mentioned then please consult the reference list of the original article.

I think Louise summed it up perfectly when she said we need to move away from black & white thinking. In the past very high carbohydrate diets were thought to be the only diet to follow if you wanted to partake in endurance sport. It now appears that a number of people have gone from one extreme to another stating that you simply have to follow a LCHF lifestyle.

While I see the benefits of sometimes limiting carbohydrate intake, especially if you want to reduce body fat, the fact remains that the evidence strongly suggests that if you want to perform well at higher intensities following a strict low-carb diet will be detrimental.

That is why here at GDRB we will offer you a personalised nutrition plan where we will modify the amount, timing, type of carbohydrate, fat and protein depending on your training goals and at what point you are in your training programme.  For more info please email wayne@gabinetederueda.es