A pulsating protein supply for muscle building

Here's what you need to know...

1. You don't need to keep blood amino acid levels elevated all day to build muscle.
2. A pulsing protein intakeis a great way to keep your body in an anabolic state, even if you eat less frequently.
3. All the benefits of fasting can also be achieved by following a very low-carb diet - except for one: in terms of muscle protein synthesis, more frequent meals are superior to fasting.

Some recent research has forced us to question one of the most sacred cows of muscle building nutrition. In short, the widely held belief that you should keep blood amino acid levels elevated throughout the day to build muscle is wrong.

While this is not necessarily absolute news, science has definitively confirmed that the best approach is to combine less frequent meals with a pulse-like protein intake. Here is new scientific evidence to support that timing your amino acid intake correctly or pulsing your protein intake is the optimal approach.

A constant amino acid intake

The old-school view was that if you continuously fed amino acids, you would continuously stimulate protein synthesis and muscle building. In other words, it was believed that protein synthesis would be increased if amino acid levels were elevated.

However, this is simply not the case. Bohé and colleagues continuously fed amino acids to a group of 30-year-old strength athletes for 6 hours. They found that not much happened in terms of protein synthesis during the first 30 minutes, but the rate of protein synthesis increased by a factor of 2.8 and remained at this level for 2 hours before dropping sharply within a short period of time - even though amino acid levels remained elevated after the 2 hours.

So continuously flooding the body with amino acids will not cause your muscles to grow more. There appears to be something of a refractory period - a time when your body needs a break from the continuous supply of amino acids so that it can regroup before resuming protein synthesis.

The effect of amino acids

Does this mean that we only have a few lean opportunities per day to stimulate protein synthesis? Not necessarily.

Another group of scientists from Galveston set out to hack this system. They wanted to see if pulsing amino acid intake (along with carbohydrates) between meals would result in higher net protein synthesis than just eating a few solid meals throughout the day. Over the course of the 16-hour study period, study participants alternated between meals of whole foods and an amino acid/carbohydrate drink every 2.5 hours.

The scientists found that by pulsing amino acids between meals, they were able to increase protein synthesis without interfering with the anabolic effects of the actual meals. So by using a pulse-like amino acid intake between meals, you can bypass the refraction phase to a certain extent in order to increase anabolism.

Time-dependent effects: The weak points of fasting

Why should you pulse your amino acid intake between meals? Why can't you just eat more protein when you eat? People who do intermittent fasting have long periods during the day when they don't eat and then eat large amounts of protein. This seems to work - but does it really work?

All the benefits of fasting can also be achieved by following a very low carbohydrate diet, except for one - in terms of muscle protein synthesis, regular meals kick fasting's butt.

There is a time-dependent upper limit to protein synthesis and you can't just eat more protein later to make up for not eating protein earlier in the day. This is the reason why the timing of protein intake is important. The irony is that we learned this important information from a group of people with the worst eating habits - average Americans!

The average American eats very little protein at breakfast and lunch and consumes large amounts of protein during dinner. Scientists at the University of Texas took this traditional dietary pattern and wanted to see if splitting the amount of protein consumed at dinner throughout the day would make a difference in protein synthesis.

The subjects were given either 30 or 90 grams of protein in the form of lean ground beef. The scientists found that splitting both amounts of protein increased protein synthesis by about 45%.

What's the message here? You can't just eat more protein later in the day to make up for missed opportunities for protein synthesis earlier in the day.

The 30 gram myth

At this point I would like to reiterate that the 30 gram protein rule is a myth. The body can easily process far more than 30 grams of protein per serving, as protein is needed for many bodily functions, not just protein synthesis.

I tend to see 30 grams as the minimum for a protein serving. This helps to ensure that you get the most out of the temporary increase in protein synthesis and more muscular athletes should consume even larger protein portions. In addition, protein synthesis rates have been shown to decrease with age, so strength athletes over 40 may need larger protein portions to achieve the same increase in protein synthesis rates as their younger counterparts.

So if you're over 40 and weigh 115 kilos, the 30 gram rule is even more invalid! Fortunately, the solution is simple - just eat larger protein portions! That's great news for any meat-loving man over 40.

Increase your protein synthesis rate with exercise

Eating protein isn't the only way to increase your protein synthesis rate. You can easily further increase the effects of protein on protein synthesis with additional resistance training.

A 2012 study found that post-workout protein had an incremental effect on protein synthesis when protein was administered in doses of 10, 20 and 40 grams. The graph below shows the effects of increasing protein intake in the form of beef (0 grams, 12 grams, 24 grams and 36 grams of protein) with additional training on muscle protein synthesis.

At the highest protein dose, leucine oxidation was also highest, showing that there was a transition from synthesis (building) to oxidation (burning). This suggests that the largest protein dose - 36 grams - was close to the upper limit in terms of protein synthesis.

The protein in this study was consumed after exercise, but it is important to remember that the mechanical stress of training with weights leads to an increase in amino acid uptake.

Therefore, by loading up on amino acids prior to the training session, we can potentially increase the availability of these anabolic amino acids for uptake during training, further enhancing the effects of combining protein and weights training.

Interestingly, the benefits of training with weights in terms of increasing protein synthesis rates are not limited to during and immediately after exercise, but continue for up to 48 hours.

All the data on protein, training with weights and protein synthesis suggests that the more often you can train with weights, the better for maximum results. If you combine this with the effects of training on insulin sensitivity, then you should train at least four times a week.

In this context, it is also important to push the limits of recovery so that we can train more and harder. By doing this, you will increase protein synthesis, which will allow you to grow stronger and train harder.

The ideal protein/amino acid intake

So what is the ideal meal plan? This depends on how many calories you are consuming and how long you are awake. From a timing perspective, solid food meals should be at least 4 to 5 hours apart.

A good rule of thumb is that the less you eat (such as during a diet), the longer the gap between meals should be, as the total number of meals you eat will be less. However, as you eat less frequently, meals can be larger - because even if protein is well satiating, a larger meal will be even more satiating.

If the gap between your meals is 5 hours, then you should provide an amino acid boost every 2.5 hours between meals, which can come from either BCAAs or a highly hydrolyzed protein consisting primarily of di- and tripeptides.

Science has spoken

You don't have to make yourself a slave to a strict meal plan to build a body that stands out from the crowd. However, this doesn't mean that a regular protein intake is no longer necessary. Use the power and convenience of a pulse-style protein intake to your advantage.

References

1. Areta, J. L. (2013). "Timing and distribution of protein ingestion during prolonged recovery from resistance exercise alters myofibrillar protein synthesis." The Journal of physiology 591: 2319-2331.
2. Bohé, J. (2001). "Latency and duration of stimulation of human muscle protein synthesis during continuous infusion of amino acids." The Journal of physiology 532: 575-579.
3. Churchward-Venne, T. A. (2012). "Nutritional regulation of muscle protein synthesis with resistance exercise: strategies to enhance anabolism." Nutrition & Metabolism 9(1): 40.
4. Glynn, E. L., C. S. Fry, et al. (2010). "Excess Leucine Intake Enhances Muscle Anabolic Signaling but Not Net Protein Anabolism in Young Men and Women." The Journal of Nutrition 140(11): 1970-1976.
5. Kim, P. L., R. S. Staron, et al. (2005). "Fasted-state skeletal muscle protein synthesis after resistance exercise is altered with training." The Journal of physiology 568(1): 283-290.
6. Moore, D. R., J. E. Tang, et al. (2009). "Differential stimulation of myofibrillar and sarcoplasmic protein synthesis with protein ingestion at rest and after resistance exercise." The Journal of physiology 587(4): 897-904.
7. Paddon-Jones, D., M. Sheffield-Moore, et al. (2005). "Exogenous amino acids stimulate human muscle anabolism without interfering with the response to mixed meal ingestion." American Journal of Physiology - Endocrinology and Metabolism 288(4): E761-E767.
8. Pasiakos, S. M. (2012). "Exercise and Amino Acid Anabolic Cell Signaling and the Regulation of Skeletal Muscle Mass." Nutrients 4(7): 740-758.
9. Robinson, M. J. (2013). "Dose-dependent responses of myofibrillar protein synthesis with beef ingestion are enhanced with resistance exercise in middle-aged men." Applied physiology, nutrition, and metabolism 38(2): 120-125.

By Mike Roussell, PhD | 10/28/13

Source: https://www.t-nation.com/supplements/protein-pulsing-for-muscle

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