Syntheselen™ is an Adenosine Triphosphate (ATP) and Uridine Triphosphate based sterile preparation manufactured by a pharmaceutical company in accordance with the highest level of manufacturing practices.
The focus of this article will center on energy (ATP) and its relationship to protein synthesis. By necessity we will keep the specifics of operations at molecular level to a minimum.
Protein Synthesis during resistance exercise
What has long been known?
It has been established for some time now that both muscle protein synthesis 1-4 and muscle protein degradation are stimulated by resistance exercise2-4.
Traditionally the overall net effect (synthesis - degradation = + or -) has been understood to depend on what happens in the post exercise environment.
In that environment protein degradation is brought to an end if carbohydrates are ingested following resistance exercise while net protein synthesis (i.e. protein synthesis exceeds protein degradation) is achieved only if both carbohydrates and protein are ingested following the resistance exercise session 5-10.
These concepts are so well established as evidenced by the numerous references cited herein that it is barely worth mentioning.
What is interesting however and worth spending some time on is what happens to protein synthesis during resistance exercise.
Achieving that understanding allows us to move into a new area and explore the concept of energy balance and protein synthesis and thanks in part to recent research examine the specific relationship between ATP concentration and protein synthesis.
Where this article intends to go
Energy state in general and ATP concentration specifically is vitally important in the fueling of muscular movement and contraction. ATP is often discussed in the context of sports as a means to reduce fatigue.
Yet protein synthesis is an extremely energy demanding process requiring the utilization of ATP. The availability of energy, specifically ATP is a limiting factor in the synthesis of muscle protein.
The extent to which protein synthesis will occur is dependant on several factors not the least of which is the availability of ATP. When we engage in resistance exercise we are using energy that will not be available to the components of the system which drive muscle protein synthesis and subsequently tissue accrual.
Is it possible to engage in resistance exercise and have net protein synthesis occur at the same time?
What has recently been understood?
In contrast to protein metabolism in the post exercise environment very little was known about the effect of nutrition on muscle protein synthesis during exercise until the year 2008. Up until that time only two studies had been done and they weren’t even done on muscle. Rather they focused on whole body protein turnover. They reported an increase in whole body protein balance after protein and carbohydrate ingestion during exercise but neither one examined what was happening at the muscular level during exercise11, 12.
The Tipton study 12 did go a step further and examined muscle protein synthesis post exercise. This led them to suggest that protein ingestion before, rather then after exercise might better increase net muscle protein accretion during post exercise recovery.
The effect of protein and carbohydrate ingestion on muscle protein synthesis during exercise was eventually established in 2008 when Beelen, et al published Protein coingestion stimulates muscle protein synthesis during resistance-type exercise, Am J Physiol Endocrinol Metab 295: E70–E77, 2008.
In that study they proved that even in the fed state, additional coingestion of protein and carbohydrates before and during resistance exercise improved whole body protein balance and stimulated muscle protein synthesis during exercise.
They didn’t just find a little benefit, rather they found that ingestion of protein and carbohydrates substantially increased muscle protein synthesis rates. This led them to conclude:
“Consequently, our findings suggest that protein coingestion during exercise could represent an effective dietary strategy to further augment muscle protein accretion by creating a larger time frame for muscle protein synthesis to be elevated.”
Although the authors did not specifically frame their results in terms of energy we can do that. Previous studies that demonstrated that resistance exercise stimulated both muscle protein synthesis and breakdown rates found that in the absence of subsequent food intake net protein balance remained negative 1,2,4.
Previous studies carried out their investigations using participants who were subjected to an overnight fast. Dreyer et al reported lower muscle protein synthesis rates during resistance exercise compared with rest and post exercise recovery 13. This strongly contrasts with the results from the aforementioned Beelen, et al study leading the authors to underscore the difference in methodology:
“The apparent discrepancy might be explained by the fact that subjects in the present study were investigated in the fed state and ingested carbohydrate with or without additional protein during exercise.”
Since the Beelen, et al study was published several studies have been published with what appears to be mixed results involving various protocols. The elderly for example have a difficult time engaging protein synthesis no matter what the protocol. A good example of a study that appears to contrast the Beelen, et al study but actually doesn’t when the methodology is examined is Essential amino acid and carbohydrate ingestion before resistance exercise does not enhance postexercise muscle protein synthesis, Satoshi Fujita, J Appl Physiol 106: 1730-1739, 2009. In that study they administered essential amino acids and carbohydrates one hour before exercise and found an increase in muscle protein synthesis which returned to base during exercise.
This study underscores the concept of energy inputs driving both muscle contractions and energy intensive protein synthesis and highlights the need to sufficiently meet that energy requirement throughout the exercise period.
References:
1 – Biolo G, Maggi SP, Williams BD, Tipton KD, Wolfe RR, Increased rates of muscle protein turnover and amino acid transport after resistance exercise in humans, Am J Physiol Endocrinol Metab 268: E514–E520, 1995
2 – Phillips SM, Tipton KD, Aarsland A, Wolf SE, Wolfe RR, Mixed muscle protein synthesis and breakdown after resistance exercise in humans, Am J Physiol Endocrinol Metab 273: E99–E107, 1997
3 – Sheffield-Moore M, Yeckel CW, Volpi E, Wolf SE, Morio B, Chinkes DL, Paddon-Jones D, Wolfe RR , Postexercise protein metabolism in older and younger men following moderate-intensity aerobic exercise, Am J Physiol Endocrinol Metab 287: E513–E522, 2004
4 – Tipton KD, Ferrando AA, Williams BD, Wolfe RR, Muscle protein metabolism in female swimmers after a combination of resistance and endurance exercise, J Appl Physiol 81: 2034–2038, 1996
5 – Biolo G, Tipton KD, Klein S, Wolfe RR, An abundant supply of amino acids enhances the metabolic effect of exercise on muscle protein, Am J Physiol Endocrinol Metab 273: E122–E129, 1997
6 – Borsheim E, Tipton KD,Wolf SE,Wolfe RR, Essential amino acids and muscle protein recovery from resistance exercise, Am J Physiol Endocrinol Metab 283: E648–E657, 2002
7 – Koopman R,Wagenmakers AJ,Manders RJ, Zorenc AH, Senden JM, Gorselink M, Keizer HA, van Loon LJ, Combined ingestion of protein and free leucine with carbohydrate increases postexercise muscle protein synthesis in vivo in male subjects, Am J Physiol Endocrinol Metab 288: E645–E653, 2005
8 – Miller SL, Tipton KD, Chinkes DL, Wolf SE, Wolfe RR , Independent and combined effects of amino acids and glucose after resistance exercise, Med Sci Sports Exerc 35: 449–455, 2003
9 – Rasmussen BB, Tipton KD, Miller SL, Wolf SE, Wolfe RR, An oral essential amino acid-carbohydrate supplement enhances muscle protein anabolism after resistance exercise, J Appl Physiol 88: 386–392, 2000
10 – Tipton KD, Ferrando AA, Phillips SM, Doyle D Jr, Wolfe RR , Postexercise net protein synthesis in human muscle from orally administered amino acids, Am J Physiol Endocrinol Metab 276: E628–E634, 1999
11 – Koopman R, Pannemans DL, Jeukendrup AE, Gijsen AP, Senden JM, Halliday D, Saris WH, van Loon LJ, Wagenmakers AJ, Combined ingestion of protein and carbohydrate improves protein balance during ultra-endurance exercise, Am J Physiol Endocrinol Metab 287: E712– E720, 2004
12 – Tipton KD, Rasmussen BB, Miller SL, Wolf SE, Owens-Stovall SK, Petrini BE, Wolfe RR, Timing of amino acid-carbohydrate ingestion alters anabolic response of muscle to resistance exercise, Am J Physiol Endocrinol Metab 281: E197–E206, 2001
13 – Dreyer HC, Fujita S, Cadenas JG, Chinkes DL, Volpi E, Rasmussen BB, Resistance exercise increases AMPK activity and reduces 4E-BP1 phosphorylation and protein synthesis in human skeletal muscle, J Physiol 576: 613–624, 2006