MARTIN_9B escribió:Estas mencionando textos de Clemente Henandez y parecidos de los años 80.
Desconozco ese autor, yo solo leo literatura en inglés, mucho más confiable y actualizada.
MARTIN_9B escribió:Por supuesto que hay diferencia.
Voy a tratar de ser más específico al respecto de mi postura.
La única diferencia entre tomar el suplemento de proteínas con leche o con agua es la adición de los nutrientes y calorías que la leche tenga, ni más ni menos. La absorción de los aminoácidos presentes en el suplemento no se verán afectados ni en calidad, ni en rapidez por realizar la mezcla con leche.
Por otro lado, cabe decir que la velocidad de absorción de la proteína o el tipo de ésta ingerida realmente NO es relevante para individuos que no sean entrenadores de competición. Importa en un porcentaje mayor al 90% la ingesta de la cantidad de proteínas y calorías adecuadas, no la absorción ni el tipo de proteínas.
MARTIN_9B escribió:]Dicho esto, porsupuesto que hay diferencia y muchisima. Sencillamente, aun que discutas mas y mas el tema de la velocidad de absorcion (que estudios recientes demuestran lo que menciono),
Por favor, cita dichos estudios para contrastarlos. Si se va a utilizar lo de "estudios" como defensa de un argumento, siempre hay que citarlos en favor de los demás lectores, y de quien pregunta inicialmente.
MARTIN_9B escribió:peor por otro lado me sorprende que ni te importe el sodio ni la salud del estomago con la lactosa (que es un carbohidrato de bajisima calidad)
Temas que no son acordes a la discusión y no favorecen ni descartan ningún argumento. Por favor, centrarse en el tema principal.
MARTIN_9B escribió:Lo mejor sera consumir proteinas de diferentes matrices, como un trimatrix, que encima que no valen ni una tercera parte economicamente hablando, encima nos aportan todos los tipos de proteinas. Pq comprar sueros microfiltrados unas tres veces mas caras?
Estoy de acuerdo en consumir todos los tipos de proteínas existentes. En desacuerdo en el marketing presente en el párrafo: ningún suplemento es necesario para consumir las proteínas necesarias, y la leche sola es mucho más amable con el bolsillo que cualquier suplemento, y mucho mejor.
MARTIN_9B escribió:En fin, que cada uno saque su propia conclusion pero yo hablo de estudios recientes. Q os vaya bien
El siguiente artículo (muy interesante e informativo), proveniente de Alan Aragon, un autor de renombre y actualizado, promueve el concepto de que no importa tomar las proteínas con agua o con leche, y que incluso podría ser mejor tomarlas con leche en post entrenamiento. Todo ello con sus respectivas referencias a estudios y textos. No cuento con la traducción en español, pero de ser necesaria puedo hacerla para quien abrió el tema.
Clearing Up Casein's Misunderstood Role in Workout Nutrition
By Alan Aragon
Dairy Protein Primer
God bless the dairy industry. Who would have known that pitchfork-toting guys in straw hats and overalls would play a tremendous role in bodybuilding nutrition? In the dawn of the sport, cow's milk has been regarded as a staple bodybuilding food. The reasons milk works so well for size and strength gains have only recently been investigated. By now it's pretty common knowledge that milk protein consists of a combination of whey and casein. Casein is the dominant fraction of milk protein (82 percent) with whey rounding out the remainder (18 percent). Minor but commercially significant milk proteins are lactoferrin and lactoperoxidase. It's well known that casein and whey are among the most biologically available proteins in the food supply.
Primary Differences Between Whey and Casein
Whey and casein have distinctly different composition and physiological effect. Whey is higher than casein in leucine, isoleucine, lysine, and the sulfur-containing amino acids. In contrast, casein has more phenylalanine, tyrosine, and aromatic amino acids. Casein has a more intimate link with IGF-1 binding capacity, while whey has been noted for its ability to suppress oxidation. Casein is the slowly absorbed fraction, and whey is the quick one. As a result, whey has a greater effect on protein synthesis, while casein has a greater effect on nitrogen retention and the prevention of protein breakdown. Casein holds the less glorious position of keeping the floor from crashing into the basement, while whey has been in the spotlight raising the roof.
The Obsession with Speed
Traditional thinking about postworkout nutrition has been all about speed. It all began with the rate of appearance of plasma glucose directly affecting the rate of glycogen synthesis. Higher glycemic response equals quicker glycogenesis (glycogen synthesis), and presumably, quicker recovery. That objective is just perfect if you're an ultra-endurance athlete with multiple sessions in a single day. Ironically, all of the nutrient timing principles bodybuilders have adopted are derived from research geared toward endurance sports, where the athlete's structure and function is nearly the opposite of the bodybuilder.
So, are there crossover lessons to be applied? Yes and no. From a cellular hydration standpoint, it certainly can't hurt bodybuilders to follow suit and maximize the rate of glycogenesis. But in most cases, the glycogen you used up during training is easily restocked by the same time the next day, regardless of whether you consume "fast" or "slow" proteins and carbs after working out. In addition, all the research indicating the anabolic benefit of quick postworkout substrates was done on subjects in an overnight fasted state, in the absence of a preworkout meal or shake - not exactly the real-world workout conditions of typical bodybuilders.
Whey Became the Dextrose of the Protein World
Dextrose was recognized for quite some time as the quickest carb, and thus best for postworkout recovery. Naturally, a whey plus dextrose combination became the standard for postworkout nutrition due to the quickly absorbed nature of each substrate. But again, the postworkout nutrition objectives were all based upon unrealistic conditions in a nearly irrelevant population (fasted endurance trainees). People around the world spouted off familiar advice: "You shouldn't have casein postworkout because it will hinder the absorption of the whey and dextrose." And hence the whey-only era continued. Some folks have latched onto the speed of absorption idea and swear (without evidence) that whey hydrolysate is better than whey isolate or whey concentrate. Still others will take the concept even further and trade out their steak for a bowl of free-form aminos, which are more quickly absorbed. Naturally, milk was supposed to be avoided postworkout, because it formed viscous clumps of gel in your gut that scared off the whey, rendering it useless. Well, at least that's how a lot of people made it sound. Meanwhile, research began to trickle in and change the way we viewed the situation.
Is Faster Better?
About a decade ago, Boirie's team compared the absorption rate and leucine kinetics of 30 grams casein to 30 grams whey, and their results were very interesting. Casein elevated blood amino acid levels for up to 300 minutes post-ingestion [1]. Whey, on the other hand, caused higher amino acid levels at the 100 minute point, and returned levels to baseline at 300 minutes. Casein caused a smaller increase in protein synthesis, but unlike whey, casein also inhibited protein breakdown.
The striking aspect about this study was the casein group achieved a better leucine balance than the whey group, indicating better nitrogen retention, thus better protein utilization. Casein caused a greater net positive protein balance than whey. This was a big win for casein, because all we really care about is remaining in a trend of positive protein balance amidst continual protein turnover.
In a later similar study, it was found that aside from known factors (including quantity of calories, amino acid composition, and micronutrition), the speed of digestion is an independent regulator of protein balance [2]. In other words, slower actually was observed to be better. Now let's see what happens when the rubber meets the road in comparison trials measuring the relevant endpoints.
The True Test: Comparative Effects On Body Composition and Strength
Seven years ago, Demling and Desanti compared the effect of a casein-dominant meal replacement product with a whey supplement. Overweight healthy police officers underwent a structured exercise program that included resistance training, under slightly hypocaloric conditions [3]. The dosing of each treatment was twice daily, once postworkout, and again 8-10 hours separately. The results? Whey got whooped by the casein-based meal replacement for strength gain, lean body mass gain and fat loss. Can we blame the superiority of the casein blend's results all on the 20 grams of carbohydrate it contained? Overall carbohydrate intake was controlled between the groups, however carbohydrate timing was not controlled, so carb timing could have made a minor impact. About a year after that study, Wojcik and colleagues compared an all-carbohydrate drink with a milk-based carb/protein recovery drink [4]. Each drink was dosed immediately postworkout and again two hours later. The results? No significant difference in rate of glycogen resynthesis.
More recently, Kerksick's team compared the strength and body composition effects of three treatments on resistance-trained men. One group received 40 grams of whey plus eight grams of casein. Another received 40 grams of whey plus three grams of BCAA plus five grams of glutamine. The last group received 48 grams of carbohydrate [5]. The supplements were ingested postworkout and on the mornings of non-exercise days. The casein/whey group had the greatest increase in lean mass, the carbohydrate group came in second without any gain, and the whey/BCAA/glutamine group actually lost lean mass. Calories were poorly controlled in this trial, But still, fast-absorbing whey and BCAA didn't shine as the be all and end all of protein and amino acid supplements.
The latest dairy protein fight as of this writing was performed by Cribb's team, who saw high-dose whey beat high-dose casein for strength gain, lean mass gain, and fat loss [6]. But once again, calories weren't controlled as tightly as necessary to level the playing field and allow us to draw any firm conclusions.
So Where Does This Leave Us?
The research comparing casein and whey is split almost right down the middle. Where it's headed from this point is really anyone's guess. Undoubtedly, funding source will play a big role in the direction of the research results. As the evidence stands, it certainly wouldn't hurt, and might actually be optimal to have a blend of the two and reap the best of both worlds. A popular practice is to have casein pre-bed, and whey near the training bout. But the reality is, the training bout is the most acutely catabolic point in your day, even though it's a necessary trigger for anabolism. Think about it, sleep ain't got NOTHING on the immediate muscle damage caused by battling the iron. So, why not have both of the best tools for each job present in circulation at the most critical point? Let's look at things logically. By saying that casein might get in the way of whey, we might as well say that the carbohydrate might get in the way of the protein, so let's separate them? Wrong. Protein and carbs act synergistically to increase muscle protein synthesis and inhibit protein breakdown. The same synergy can be achieved by having a combination of whey and casein near the workout. Maybe Mother Nature was right all along.
References
1. Boirie Y, et al. Slow and fast dietary proteins differently modulate postprandial protein accretion. Proc Natl Acad Sci USA 1997;94(26):14930-5.
2. Dangin M, et al. The digestion rate of protein is an independent regulating factor of postprandial protein retention. Am J Physiol Endocrinol Metab. 2001 Feb;280(2):E340-8.
3. Demling RH, DeSanti L. Effect of a hypocaloric diet, increased protein intake and resistance training on lean mass gains and fat mass loss in overweight police officers. Ann Nutr Metab 2000;44(1):21-9.
4. Wojcik JR, et al. Comparison of carbohydrate and milk-based beverages on muscle damage and glycogen following exercise. Int J Sport Nutr Exerc Metab. 2001 Dec;11(4):406-19.
5. Kerksick, et al. The effects of protein and amino acid supplementation on performance and training adaptations during ten weeks of resistance training. J Strength Cond Res. 2006 Aug;20(3):643-53.
6. Cribb, et al. The effect of whey isolate and resistance training on strength, body composition, and plasma glutamine. Int J Sport Nutr Exerc Metab. 2006;16:494-509
A partir de ahí, también concuerdo en lo dicho: que cada quien saque su propia conclusión al respecto.
