Maximising Anabolic Potential

Maximising Anabolic Potential

The processes of protein synthesis and protein breakdown occur concurrently in the muscle, and it is this constant protein turnover that allows the muscle fibre to change its protein structure accordingly, and adapt to the training stimuli over time.

On a gross level, net protein balance determines whether muscle fibre size is increased (hypertrophy) or reduced (atrophy). If protein synthesis exceeds protein breakdown then there will be a positive protein balance and a turnover of new proteins (i.e. removing damaged proteins and replacing with new). On the other hand, if protein degradation is greater, there will be a negative protein balance and here it will become extremely challenging to build muscle mass. Therefore, in order to maximise the anabolic response we should try to be in a positive protein balance as much as possible.

So how do we maximise muscle protein synthesis?

It has been well established that both resistance exercise (3) and consumption of protein or amino acids (2) are potent stimulators of protein synthesis (see figure 1). Resistance training alone causes a greater protein breakdown and negative balance and therefore, it is a combination of these two that results in a synergistic stimulation of muscle protein synthesis which eventually leads to muscle growth (1). The main questions to pose when wanting to maximise this anabolic response is 1) what type of protein is best? 2) What is the best time to take protein? And 3) how much protein (total) should you take?

Rate of MPS and MPB

Figure 1. Rates of muscle protein synthesis (MPS) and muscle protein breakdown (MPB) following consumption of protein and the response to resistance based exercise (Adapted from Phillips et al., 2009 (4)).

1) What Type of Protein.

Maximising Anabolic Potential

As mentioned, protein can stimulate muscle protein synthesis following a bout of resistance exercise, and the rate at which this stimulates muscle protein synthesis can vary significantly depending on the type of protein. In particular, the essential amino acid leucine occupies a position of prominence since, unlike any of the other amino acids, it acts purely as a stimulatory signal to switch on muscle protein synthesis (6). It should be noted though, that leucine also needs a full complement of the other essential amino acids (EAA’s) to maximise this response (8).

It is rapidly digestible proteins such as whey protein that contain high proportions of EAA’s, of which the key amino acid appears to be leucine, that are more effective in stimulating protein synthesis than many other types of protein (soy, casein etc.). However, advantages of casein may accrue when ingested at night, where the slow release may aid recovery whilst sleeping (7).

Taking this into consideration, whey protein appears to tick all the boxes and it can be particularly beneficial in supporting a positive protein balance throughout the day. It goes without saying that high protein foods such as lean meats and fish should be the forefront of any diet, but whey protein can be a useful tool to support any additions to protein intake.

2) When to Take Protein?

The timing of protein ingestion has been identified as another key factor modulating post-exercise muscle protein anabolism. Generally, the muscle is most responsive to protein synthesis activation by amino acids immediately following exercise.

Increasing the amino acid concentration in the blood (often by protein intake such as whey protein) following resistance training (anything from 1-5 hours) will ensure that you take advantage of the mechanisms at the cellular level that are activated following exercise (6). It is here where the enzymes responsible for muscle growth are more active and the key nutrients are more likely to be absorbed into the muscle cells. In order to maximise the anabolic response, the general consensus by most practitioners would be to have protein within the first hour following training – this timeframe is commonly referred to as the ‘window of opportunity’ and is thought to maximise the anabolic response. Taken with fast releasing carbohydrates (such as Maltodextrin) has been said to further augment post-exercise muscle protein accretion too (9).

The impact of pre-exercise feeding has also received particular attention in the past few years. Tipton and colleagues (9) from the University of Stirling found that pre-exercise consumption of amino acids led to an enhanced post-exercise net amino acid balance. With this in mind, it could also be recommended to consume some form of fast digesting protein (high in EAA’s) 2-3 hours prior to training. The type of protein is fundamental here as the aim would be to also minimise any effects of gastrointestinal discomfort throughout the session. Branched Chain Amino Acids (BCAAs) is a good supplement, often used by many athletes to avoid this issue.

Maximising Anabolic Potential

3) How Much Protein?

The amount of protein that is consumed across a day and in each meal is also fundamental to net protein balance. Those taking part in intense physical exercise will have a greater protein turnover and therefore dietary protein requirements are increased. Based on this, it is recommended for a physically active individual to consume 1.2-1.6g per kg of body weight per day (e.g. a 70kg individual will consume on average 100g of protein per day). This should come from a range of nutrient-dense foods such as pastured meats, poultry and oily fish and then maybe one or two additional supplements (such as whey or casein) to help along the way.

A guidance of 20-30g of protein in every meal (spread between 3-4 hours) will help you to reach these levels of protein. Ensuring you have 20-30g protein post workout (whether it be from a whey protein shake or a meal) will also allow you to increase total protein intake on training days.

Overview of Recommendations.

  • Consume protein before and after exercise to maximise protein synthesis and promote adaptation.
  • Liquid forms of protein such as whey have a rapid digestion rate and therefore provide a faster release into the muscle.
  • Whey protein has a greater leucine content to many other protein sources (such as soy, casein) and is arguably the best protein source to stimulate muscle protein synthesis and reduce protein breakdown.
  • It is recommended to consume 20-30g protein per meal around 4-5 times a day at regularly spaced intervals to maximise the anabolic response.
  • Excessive amounts of protein are not necessary for performance, however, levels of protein intake in the range of 1.2-1.6 g protein/ kg body weight would be adequate and more than required by most people participating in heaving resistance based training.

Author

Steve has a Masters degree in Sports Physiology and works within the Bulk™ product team. His role includes all aspects of new product development, from recipe concept and formulation to website content and legislations.

References:

  • Biolo, G., K. D. Tipton, S. Klein, and R. R. Wolfe (1997). An abundant supply of amino acids enhances the metabolic effect of exercise on muscle protein. Am. J. Physiol. 273: E122-E129.
  • Bohe, J., J. F. Low, R. R. Wolfe, and M. J. Rennie (2001). Latency and duration of stimulation of human muscle protein synthesis during continuous infusion of amino acids. J. Physiol. 532: 575-579.
  • Phillips, S.M., K.D. Tipton, A. Aarsland, S.E. Wolf, and R.R. Wolfe (1997). Mixed muscle protein synthesis and breakdown after resistance exercise in humans. Am. J. Physiol. 273: E99-107.
  • Phillips, S.M., E. I. Glover, and M. J. Rennie (2009). Alterations of protein turnover underlying disuse atrophy in human skeletal muscle. J. Appl. Physiol. 107: 643-654.
  • Philp A., D. L. Hamilton, and K. Baar (2011). Signals mediating skeletal muscle remodelling by resistance exercise: PI3-kinase independent activation of mTORC1. J. Appl. Physiol. 110: 561-568.
  • Philp A., D. L. Hamilton, and K. Baar (2011). Signals mediating skeletal muscle remodelling by resistance exercise: PI3-kinase independent activation of mTORC1. J. Appl. Physiol. 110: 561-568.
  • T Snijders, PT Res, JSJ Smeets, S van Vliet, J van Kranenburg, K Maase, AK Kies, LB Verdijk, LJC van Loon. Protein Ingestion before Sleep Increases Muscle Mass and Strength Gains during Prolonged Resistance-Type Exercise Training in Healthy Young Men. J Nutr In press Apr 29, 2015.
  • Tipton, K.D., A. A. Ferrando, S. M. Phillips, D. Doyle, Jr., and R. R. Wolfe (1999). Post exercise net protein synthesis in human muscle from orally administered amino acids. Am. J. Physiol. 276: E628-E634.
  • Tipton, K.D., B. B. Rasmussen, S. L. Miller, S. E. Wolf, S. K. Owens-Stovall, B. E. Petrini, and R. R. Wolfe (2001). Timing of amino acid-carbohydrate ingestion alters anabolic response of muscle to resistance exercise. Am. J. Physiol. 281: E197-E206.

 

Did you enjoy this article?

Thank you for your feedback

Related Products