Day 115 - Nutrient Timing for Resistance Exercise Part 3
Part 1 the other day covered nutrient timing prior to exercise, and how it effects performance.
Part 2 dealt with post-exercise nutrition and how it effects recovery.
For those of you who may have missed part 1 or part 2, I came across an absolutely amazing article in the Strength and Conditioning Journal titled, "Nutrient Timing for Resistance Exercise" written by a team of PhD and CSCS certified individuals. This is probably the single-greatest resource I have come across detailing what is referred to as "nutritional timing" when it comes to resistance training, so if you are interested, pick up a copy for yourself!
Part 3: Net Protein Balance
Think of your body as a construction site, with tissues constantly being broken down and either repaired or replaced. This is known as having a 'negative' net protein balance.
Having a negative net protein balance, or in other words, a catabolic state, is stimulated from resistance training, but also occurs when the body is at rest. Tissues are being broken down due to misuse, or in the case of resistance training - use, at all times.
The focus of individuals who wish to positively grow their muscles, or induce an anabolic state, should be of great interest, especially when resistance training.
The diet is therefore of great interest for those who resistance train, as the goal of improving one's muscles to improve size and/or strength plays a key role.
When discussing post-exercise nutrition, it should be noted that carbohydrates are important to not only return the body to pre-exercise levels of glycogen (energy stores), but have also been shown to reduce muscle protein breakdown.
Having said that, individuals should consume sources of amino acids/protein following exercise in order to feed the body the proper building blocks to reduce muscle protein degradation, but to also stimulate muscular growth.
What types of protein are best? The article says:
Whole-protein sources (including whey, casein, and soy protein sources), when ingested either before or after an acute bout of resistance exercise, also significantly improve net protein balance by increasing rates of protein synthesis. In one of these investigations, it was reported that whey protein was superior to soy and casein in its ability to incrase protein synthesis (approximately 22g of each type of protein was ingested after resistance exercise). Surprisingly, even though soy is lower in quality than casein, they found that of the 3 protein sources, casein resulted in the lowest net response in protein synthesis. The authors suggested that this was a factor of the slow rate of digestion induced by casein. Therefore, after resistance exercise, it may be ideal to select a protein source high in BCAA content (whey) that is also fast digesting in nature.
Okay, so following exercise, it is best to consume either a beverage or meal containing some protein. So how much is ideal? I have seen many personal thoughts tossed around from individuals over the years, who claim to know the 'perfect amount' of protein. This article has an opinion of its own:
Research conducted at McMaster University sough to answer this question by giving male subjects (with at least 4 months of resistance training experience) 5 different amounts of protein in a randomized crossover design. Immediately after a lower-body resistance exercise bout, the subjects consumed drinks containing 0, 5, 10, 20, or 40g of whole egg protein. After consuming the whole egg protein supplement, protein synthesis was measured for the next 4 hours. Mean mixed muscle protein synthesis was maximally stimulated with 20g of whole egg protein (meaning that ingesting 40g of protein offered no additional benefit than 20g of protein in terms or maximizing protein synthesis rates). In terms of relative dosage, this amount of protein was equivalent to 0.23g of whole egg protein per kilogram of body mass.
Although a snack or meal containing amino acids/protein is highly recommended following resistance exercise, it should be noted that research shows that a mixture of protein and carbohydrates is the optimal scenario for post resistance-workout nutrition as the carbohydrates aid in reducing protein catabolism, replenish spent glycogen stores, not to mention the protein aids in tissue anabolism.
Quote of the day:
"To climb steep hills requires a slow pace at first."
~ William Shakespeare