Carbohydrate supplementation and the immune system

This is the first of three short blogs taken from the latest Exercise and Immunology Review. We will be looking at the effect of the macronutrients on exercise and the immune system. Up first, we have carbohydrate and endurance exercise. 

From the point of view of performance, the benefit of carbohydrate during endurance exercise is well established. During long training sessions and competitions, the recommended amount of carbohydrate is between 30-60g/hr and up to 90g/hr for very long events such as Iron Man. The primary aim of ingesting this amount of carbohydrate is to maintain blood glucose levels but it appears that it also has an indirect effect on the immune system. As we exercise, we increase the level of stress hormones within our body (adrenaline, noradrenaline and cortisol) and these hormones impair immune function. Illness and infections are common among athletes and I am sure we have all experienced the inconvenience of having to cut our training short due to illness. While following an habitually high carbohydrate diet does not seem to have much of an effect on immune function compared to a low carb diet, in other words, they both show similar levels of post-exercise immune depression, supplementing with carbohydrate during exercise does have an effect.

As plasma glucose falls during exercise, plasma cortisol rises. Cortisol stimulates protein catabolism and gluconeogenesis (formation of glucose from non-carbohydrate sources), it also has a potent anti-inflammatory and immune depressive effect. While there is sufficient evidence to show that supplementing with carbohydrate during endurance exercise attenuates the body’s cortisol response through maintaining plasma glucose levels, there are also reports of carbohydrate having a beneficial effect on immune function regardless of plasma cortisol levels. Simply put, carbohydrate supplementation during exercise appears to diminish the post exercise reduction in immune function. However, the catch is that the benefit of carbohydrate supplementation on immune function doesn’t appear to have an effect on the incidence of URTIs otherwise known as a cold.

The practical application

Whilst it appears that supplementing with carbohydrate may not lessen your chances of catching a cold, it does help to keep your immune system functioning when faced with the stress of exercise. This is obviously useful in terms of recovery from URTIs and fighting off other infections. I would also consider the link between carbohydrate and immune function when planning training sessions and would avoid any high intensity work during periods of low-carb or fasted training. I would probably also avoid placing a period of such training immediately after a block of high intensity training.  

Reference

Berman S et al. (2017) Immunonutrition and Exercise Consensus Statement. Exercise and Immunology Review: Vol 23

How Much Carbohydrate Do We Need (For Sports) ?

In sports nutrition, whatever the question is, the answer is usually, “it depends”. While this answer may seem very vague there really is not a one size fits all approach to nutrition and especially to sports nutrition. When it comes to how much or how often you should eat carbohydrate, protein, fat etc. etc. it really does depend on how often you train, the intensity you train at and the type of activities you do. When it comes to planning your nutrition for sport, you must think about the amount of carbohydrate you need.

Carbohydrate is the fat of the 21^st century! All our food woes are the fault of carbs and all our ills will be cured by removing carbs from our diet. Of course I’m (slightly) exaggerating here but carbohydrate has got a pretty bad reputation at the moment.

If your goal is to lose weight, reduce body fat and so on then adopting a low carbohydrate diet is worth considering. However, as covered in our previous post about low-carb diets, if you regularly practice a sport that has periods of high intensity effort then carbs are your friend. 

How much you need depends on several factors including but not limited to:

• Type of exercise you do
• Intensity
• Frequency
• Duration
• Recovery 

Another important point to remember when thinking about carb intake is, where are you in your training programme? We all know the importance of periodisation when it comes to your training, well the same must be taken into account when thinking about your nutrition. Your nutrition needs will not be the same for a leg session in the gym as they would be for a 130km bike ride so it is important to match the nutrition to the exercise.

Below are some tables that are a useful guideline to refer to when thinking about your carbohydrate needs. Of course these are guidelines and not set in stone but they are a good starting point for you when you think about planning your pre/during/post training meals. 
  
Obviously if you are currently going through some fasted training and/or are trying to reduce body fat, increase fat oxidation etc. these tables may not be appropriate. 
They are aimed at people who are currently in or are about to enter into a block of training with medium to high intensity.

The tables have been adapted from the ACSM publication “Nutrition and Athletic Performance” which can be found here

If you want to know more about planning your diet for your exercise needs, please get in touch via our website, Twitter or Facebook. 
www.gabinetederueda.es 

General Carbohydrate Needs Depending on Intensity of Exercise 

 Fuelling Strategies for Pre-Exercise 

 Carbohydrate Needs During Exercise 

 

Cuando Paleo no es Paleo

El mundo de la salud y de la nutrición es muy similar al mundo de la moda. Todos los años tenemos una dieta o “súper” alimento que debemos incluir en nuestras vidas, que rápidamente desaparecen y son substituidos por otras dietas o “super” alimentos. Otras veces pueden incluso reaparecer.

A menudo me pregunto qué pasó con la dieta “metabólica”. Cuando terminé la universidad y empecé trabajar como entrenador personal, ésta dieta era LA DIETA a seguir según los “gurus” de la salud y el ejercicio. Por supuesto, esta dieta vino y se fue. Fue substituida por la dieta alcalina, la dieta del grupo sanguíneo, la dieta de la zona, la dieta de ayuno etc. etc.

Ya hemos dicho en nuestro post sobre la Dieta Alcalina que muchas de estas dietas son tonterías y puedes ignorarlas. Por ejemplo, la dieta del grupo sanguíneo. Sin embargo, hay algunas dietas que tienen sus méritos.

Un buen ejemplo es la dieta paleo. En principio, la dieta paleo consiste en consumir la comida que los humanos pueden encontrar en su ambiente natural: la carne, el pescado, las frutas, las verduras, los frutos secos y las semillas. Éstos son una buena base para una dieta y siempre recomendamos a nuestros pacientes que la mayoría alimentación esté basada en este tipo de alimentos.

La teoría tras la dieta paleo es que el ser humano cometió un error cuando empezó a cultivar los granos, hacer panes etc. y que deberíamos haber continuado con nuestra dieta natural. Hay discusiones a favor y en contra de esta teoría y aunque la idea podría ser poco práctica, el conteniendo de la dieta no está nada mal.

Siempre he pensado que debe haber habido una razón por la que cambiamos de cazadores-recolectores a agricultores. ¿Quizás para tener menos de riesgo de morir de hambre?

Sin embargo, también tenemos que tener en cuenta que hoy en día la comida es abundante. ¿Quizás una dieta más “primitiva” sea necesaria?

Mi problema con la dieta paleo (y con casi todas las dietas) no es necesariamente las dietas en sí mismas, sino el tsunami de productos que están asociados con la dieta. Por definición la dieta paleo debería ser muy fácil de seguir: puedes ir al supermercado y comprar toda la comida necesaria en la zona de productos frescos.

Por supuesto, es más complicado y más caro si quieres comprar los productos ecológicos que nos recomienda la dieta paleo. Aquí en nuestro gabinete siempre recomendamos productos ecológicos cuando es posible, pero tenemos que ser realistas y aceptar que no todo el mundo puede permitirse comprar a diario productos ecológicos.

La pregunta que los seguidores de la dieta paleo se tienen que preguntar es: “¿Es mi dieta paleo de verdad?” 

Una dieta paleo estricta no puede contener los siguientes elementos:

• Té y café
• Alcohol
• Aceites 
• Azúcar añadido
• Todas las harinas y panes
• Sal añadida y por lo tanto, nada de lo siguiente:
• Carnes procesadas y curadas
• Lácteos
• Bebidas vegetales, por ejemplo, leche de soja
• Chocolate
• Todas las salsas
• Los productos de nutrición deportiva
• Y cualquier líquido que no es el agua

 Todos los elementos de esta lista son el resultado del cambio de cazadores-recolectores a agricultores. El hombre paleo habría comido solo lo que podía cazar o recoger de la tierra. Sin embargo, si escribes “productos de paleo” en Google puedes encontrar miles de páginas que venden productos para la dieta paleo.

He buscado en inglés las palabras “paleo products” y la primera página me dio “23 productos de paleo que tienes que probar” que incluían:

• Beicon (no es paleo)
• Prosciutto (básicamente igual de beicon así que no es paleo)
• Aceite de coco (no es paleo)
• Harina de coco y harina de almendras (no son paleo)
• Mantequilla (no es paleo)
• Agua con gas (¡por supuesto no es paleo!!!)
• Té (no es paleo)

Resulta de lo más divertido navegar por las interminables páginas que venden “barras de proteínas paleo” o “batidos de proteínas paleo”. Quizás estoy equivocado, pero estoy seguro que no han encontrado un mezclador/shaker fosilizado de la época paleolítica.

Si una barrita contiene fruta desecada en vez de azúcar o un batido contiene proteína de cáñamo en vez de suero, no significa que sean paleo. Son productos hechos por el hombre así que, no son paleo!!. Pasa lo mismo con las harinas y los aceites. Una harina de almendra, sigue siendo una harina, que no está permitida en la dieta paleo. ¡Ni tampoco el aceite de coco ya que requiere un proceso de fabricación!

¿Y qué?

¿A quién le importa? A lo mejor estoy siendo un poco pedante, pero éste es mi problema con este tipo de dietas y las empresas que se aprovechan. Las empresas de comida y suplementos no son tontas y pueden reconocer una mina de oro cuando la ven. Saben que si ponen la palabra “Paleo” en el paquete te pueden cobrar más y también saben que lo pagaremos ya que sabemos que la dieta paleo tiene fama de ser cara y ya nos hemos hecho a la idea de que vamos a tener que pagar un poco más.

Pero si compras cualquiera de estos productos “paleo” no estas siguiendo la dieta paleo, sino solo pagando demasiado por productos que no son necesarios.

Otra pregunta importante es ¿por qué sigues la dieta paleo? Si tienes muchas ganas de comer como un@ cavernícola, todas de las cosas de la lista arriba no están permitidas. Pero si solo quieres reducir los productos procesadas o hechos por el hombre lo puedes hacer sin comprar productos extra caros que aun así están hechos por el hombre.

Nuestro consejo es: compra local, de temporada y cuando sea posible ecológico y evita todo que tengan la palabra “Paleo” en el paquete.

  

Si quieres saber más sobre la dieta paleo o tienes una pregunta sobre tu dieta escríbenos en Facebook/Twitter o nuestra pagina 

www.gabinetederueda.es 

Amount of Protein Needed to Ingest a Good Dose of Leucine

In our previous article about post exercise protein we mentioned the importance of leucine as one of the amino acids that must be included in your post exercise meal. Leucine is a key component of skeletal muscle synthesis and current evidence suggests that with amounts of 20-45 mg leucine per kg of body weight muscle protein synthesis is optimised (1,2). Remember don't fall into the common sports nutrition trap of thinking even more leucine will turn you into Arnie. There appears to be a ceiling when it comes to protein ingestion and protein synthesis, therefore amounts larger than 45mg/kg don't appear to be beneficial (3). 

Below is a table (3) taken from the work done by Moore et al. (1) and Pasiakos et al. (2) that offers practical advice on how much total protein you would need to achieve 45mg of leucine per kg of body weight.

Use this table as a guideline when planning your post work out meal to ensure you achieve the optimum post work out leucine dose. 

For any further questions regarding nutrition and performance please get in touch 

www.gabinetederueda.es 

References 
1.Moore, D. R., M. J. Robinson, J. L. Fry, J. E. Tang, E. I. Glover, S. B. Wilkinson, T. Prior, M. A. Tarnopolsky, and S. M. Phillips. 2009. Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men. American Journal of Clinical Nutrition 89 (1): 161–168.

2.Pasiakos, S. M., H. L. McClung, J. P. McClung, L. M. Margolis, N. E. Andersen, G. J. Cloutier, M. A. Pikosky, J. C. Rood, R. A. Fielding, and A. J. Young. 2011. Leucine-enriched essen­tial amino acid supplementation during moderate steady state exercise enhances postex­ercise muscle protein synthesis. American Journal of Clinical Nutrition 94 (3): 809–818.

3.B.I Campbell 2014, Sports Nutrition: Enhancing exercise performance. CRC Press

Cafeína y deportes de resistencia

1,3,7-trimethylxanthine: a lo mejor no reconoces esta palabra, pero estoy seguro de que es tu estimulante favorito. Para la mayoría de nosotros, la cafeína constituye una parte importante de nuestro día a día en forma de café, té, chocolate, Coca-Cola o cualquiera de las diferentes opciones de bebidas energéticas.

Desde que la cafeína fue retirada de la lista de productos prohibidos en competición, en 2004, ha habido una inundación de productos de nutrición deportiva que contienen la cafeína.

La eficacia de la cafeína es muy conocida, especialmente en deportes de resistencia como el ciclismo, y es muy popular entre atletas; tanto es así, que WADA (World AntiDoping Authority) la ha puesto en su programa de seguimiento de 2016. Esto significa que están un poco preocupados de que los atletas estén abusando de la cafeína y la quieren vigilar. 

El instituto de deporte en Australia (AIS) ha puesto la cafeína en la categoría A de su lista de suplementos¹. Esto quiere decir que hay mucha evidencia que apoya el uso de la cafeína la práctica deportiva. 

En este post no quiero hablar sobre si la cafeína funciona o no, porque sí funciona. Lo que quiero aclarar son una serie de cuestiones sobre el tema de la cafeína en deporte. 

Cuánto y cuándo

En el mundo de la nutrición deportiva hay una actitud de “más es mejor” pero la realidad no es siempre así. A veces más no es mejor y puede tener efectos desagradables. Los primeros estudios demostraron que una dosis de alrededor 6mg/kg peso (300-500mg de cafeína) tuvieron un efecto positivo en una contra-reloj de ciclismo de 60 minutos. Sin embargo, el mismo efecto positivo fue encontrado en estudios posteriores con una dosis menor en cafeína, alrededor 200mg. Llegaron a la conclusión que la cafeína tiene un efecto positivo, pero parece que hay un umbral en el cual más cafeína no da lugar a una mejora en el rendimiento^2,3. En otras palabras: más es mejor hasta cierto punto.
 

Recientemente, Asker Jeukundrup repasó en su página web⁴ un estudio sobre la cafeína y el ciclismo durante más de dos horas. En el estudio los participantes montaron durante dos horas y media en bici e inmediatamente después hicieron una contra-reloj. Los participantes habían ingerido una dosis de 100mg de cafeína, 200mg de cafeína o un placebo.  Los más rápidos fueron los participantes de 200mg de cafeína, los siguientes fueron los de 100mg y los últimos fueron los del placebo.

Las recomendaciones actuales son:

En los eventos hasta una hora	200mg cafeína una hora antes del evento
En los eventos más que dos horas	200mg de cafeína 45min – 60min antes de que necesites el efecto

La fuente de la cafeína 

Ahora ya sabemos que 200mg de cafeína son la dosis óptima. Pero ¿cuánto son 200mg? Un café? ¿Diez cafés?. 

Aquí abajo hemos hecho una pequeña tabla^2,3,5 que nos dice la cantidad de cafeína en bebidas y productos deportivos.

Producto	Tamaño	Cantidad de cafeína en mg
Café en cafetera Italiana	150mls (a media una taza sin leche)	65-125
Café espresso	1 espresso	~100
Café instantáneo	150mls	40-100
Te	150mls (solo)	10 -50 (depende del tiempo que dejas la bolsa en la taza)
Chocolate	100g	15
Coca Cola	Una lata (330mls)	46
Red Bull	Una lata (250mls)	80
Monster	Una lata (553mls)	176 (además de un montón de azúcar)
Science in Sport GO Hydro+cafeína pastillas	Una pastilla (4.5g)	75
Science in Sport GO Caffiene Geles	Un gel 60mls	75
Overstims Cafein’Gel	Un gel (29g)	75

¿Y café?

¿Basta con beber un café antes de un paseo en bici? ¿O necesitamos un producto específico? Obviamente las empresas de nutrición deportiva nos dicen que tenemos que obtener nuestra cafeína de un producto específico. 

¿Pero qué dice la evidencia? Un estudio ha demostrado que el café es igual de efectivo que una bebida deportiva con cafeína⁷ en una contra-reloj. Obviamente beber un café mientras estás en la bici no es muy práctico, a no ser que quieras parar en una cafetería. 

Pero si lo que quieres es un subidón de cafeína al principio de tu entrenamiento, un café fuerte seria efectivo.

¿Cómo funciona?

En los primeros estudios se pensaba que el efecto beneficioso de la cafeína era debido a un aumento en la utilización de grasa y debido a ello, una reducción o ahorro de glucógeno². Sin embargo ahora la evidencia nos dice que la cafeína reduce la percepción de la fatiga y por eso podemos mantener un nivel de intensidad más alto durante más tiempo⁶.     

La cafeína y recuperación

Un componente muy importante de la recuperación es el sueño. Si no dormimos bien hay un riesgo de infección y tampoco podremos entrenar como queremos. 

Aunque sea obvio, tenemos que mencionarlo: entrenar con cafeína por las noches no está recomendado. La cafeína puede permanecer en nuestros sistemas hasta seis horas⁸ así que puede afectar al sueño.

Curiosamente, existe un estudio que indica que la cafeína puede reducir el dolor percibido en las piernas después de un evento ciclista de larga duración⁹. Sin embargo, creo que se necesita más estudios científicos en este tema antes de que podamos recomendar cafeína después de ejercicio, pero si eres como yo, normalmente una taza de café o té es una parte del ritual post ejercicio.

¿Nos deshidrata?

La creencia que la cafeína nos deshidrata es tan vieja como matusalén, pero ¿existe algo de verdad? En su artículo sobre la cafeína y el deporte, la Sociedad Internacional de Nutrición Deportiva (ISSN) declara que es importante recordar que el consumo de la cafeína mientras durante el ejercicio no es lo mismo que el consumo mientras estás en reposo, por ejemplo, en la oficina. Existe alguna evidencia de que la cafeína aumenta la producción de la orina en reposo, pero una vez más, no es lo mismo durante el ejercicio⁸.

El hecho es que, si mantienes los niveles de hidratación apropiados durante el ejercicio y el reposo, la cafeína NO te deshidrata.

En conclusión, los puntos clave son:

• 200mg de cafeína 45-60 minutos antes de que quieras el efecto
• Puede ser en la forma que quieras: gel, café, bebida etc.
• No perjudica la recuperación, pero no es recomendable por las noches
• No te deshidrata 

Si quieres más información sobre la cafeína, suplementos de cafeína o sobre nuestros paquetes de nutrición deportiva, escríbenos a info@gabinetederueda.es o via Twitter @DieteticodRB y Facebook @GabinetedeRuedaBradley. 

Referencias

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 athttp://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. 

When Paleo isn't Paleo

The world of health and fitness is often very similar to the world of fashion. Each year there is a must have food and/or diet and then eventually they will fade into obscurity, replaced by another diet, sometimes to reemerge a few years later. I often wonder what happened to the Metabolic Typing Diet. When I first left university and ventured into the world of fitness training this was THE diet to follow according to certain fitness "experts". Of course, it came and went, it was replaced by the Alkaline Diet, Zone Diet, Blood Type diet, the Fasting Diet, and the reemergence of the Atkins Diet, tweaked and now called LCHF, so on and so on. As I've said before in our Alkaline Diet post, a lot, if not the majority of these diets can be dismissed as nonsense, the Blood Type Diet being a good example, however, there are some of these diets that are actually OK. A good example of these is the Alkaline diet, in terms of the actual content of the diet anyway, not the reasons they give for following it.

Another good example is the Paleo diet. Taken at first glance, the Paleo diet consists of everything that the human would eat in their natural environment, so, meat, fish, fruits, vegetables, nuts and seeds. This is a sound base for any diet and we also recommend that the majority of our patients' diets are made up of fresh produce and to try and limit man made or processed products as much as possible. The idea behind Paleo is that we humans made a mistake by starting agriculture, that is farming grains, making breads etc. and that we should have stuck to our "natural" diet. There are arguments both for and against this and as I've said before the actual content of the Paleo diet or at least the idea behind it isn't too bad, if a little impractical. I always think that there must have been a reason why we went from hunter-gatherer to farmer, less chance of starving to death was probably a major factor. However, now food is abundant (in the western world at least) maybe going "back to the primitive" is a good idea.

The problem I have with the Paleo diet and to be honest nearly all diets, is not the actual diets themselves but the tsunami of products that are targeted at followers of that particular diet. By it's very nature the Paleo diet should be fairly simple to follow. Putting aside the issue of organic for one moment, you should be able to go to the supermarket and buy your food from the fresh produce aisles only. Obviously things become a little more difficult and not to mention expensive when you factor in organic produce. Of course, we promote organic, local and seasonal where possible but we have to be aware that not everyone has the budget  for that.

The question followers of the Paleo diet have to ask is, is my diet really Paleo?

If we are to be strict about it, the Paleo diet will not have any of the following

• Tea and Coffee
• Alcohol 
• Oils
• Sugar 
• Flours and breads (all types)
• Salt and therefore 
• Processed and/or cured meats
• Dairy 
• Dairy alternatives such as almond milk, soy milk etc. 
• Chocolate
• Sauces 
• Sports nutrition products 
• Any liquid that isn't water 

All of the above have come about from the human moving away from hunter-gatherer and towards agriculture. Paleo human would have only eaten what they dug up from the earth, picked from a tree, hunted or scavenged. However, after a quick google search for Paleo products, top of the list is a  website that recommends 23 "paleo products" you have to try and they include,

• Bacon (not Paleo)
• Prosciutto (basically bacon so not Paleo)
• Coconut oil (not Paleo)
• Coconut and almond flours (not Paleo) 
• Butter and Ghee (not Paleo) 
• Sparkling water (not Paleo) 
• Tea (not Paleo) 

Things get really amusing when you browse through the enormous list of Paleo protein bars and Paleo protein powders! Maybe I'm wrong but I'm fairly certain that archaeologists are yet to find any fossilised protein shakers from the Paleolithic period. Just because a bar contains dried fruit instead of sugar or a powder is using hemp protein instead of whey, the fact it is a processed man made product means it is NOT Paleo. The same can be said for flours and oils, almond flour is still a flour, it's processed, as is coconut or any other oil. 

So What?

Who cares right? Maybe I am just being pedantic but this where my issue with "diets" comes from. The food and supplement companies are not stupid and they can spot a gold mine when they see one. They know that if they slap the word Paleo on the wrapper of a product they can hike the price up and people will pay it, especially as the Paleo diet is known for not being cheap and so people already expect to pay a bit more. But if you are buying any of those products you are not following a Paleo diet you are paying over the odds for products that you could buy ordinarily at a fraction of the price.  

It boils down to the question of why are you following the Paleo diet? If you really want to eat like a cave man/woman then unfortunately anything off that list above is out of bounds. Or if you simply want to decrease the amount of processed or man made foods in your diet you can do so without having to buy overpriced products. 

Our advice is, buy local, buy seasonal and avoid anything that has Paleo on the wrapper!  

If you want any help or advice regarding Paleo or any diet, drop a comment below or contact us on Facebook/Twitter or info@gabinetederueda.es 

References 

http://wickedspatula.com/23-paleo-items-you-have-to-buy-at-trader-joes/ 

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.