By Keith Cormican
If you are living in the fitness capital of the world –LA, it’s not too hard to find a quality California personal trainer & it would be very wise to get their views on the importance of protein intake for increasing muscle mass.
Increased muscle mass is typically a goal of strength athletes, and may also be the aim of everyday gym users. It has long been an accepted belief, amongst bodybuilding and strength training athletes, that eating high levels of protein, especially meat, is the way to gain strength and put on size. This goes back to the Olympians of the Greek era and is still believed by a lot of modern day athletes. I am sure you could gather plenty of anecdotal evidence to support this view from bodybuilders and strength athletes in your local gymnasium. Whether this would stand up to close scientific scrutiny is another matter.
A pound of muscle consists of approximately 100 grams of protein. Therefore to increase your muscle mass by 0.5 kg/week, in theory you would need to be consuming an extra 14 grams of protein per day (100 grams divided by 7 = 14). This is quite easily obtained by simply increasing your overall food consumption. With 20% of your calories coming from protein, 4000 calories would provide you with 200 grams of protein which equates to 2.8 grams of protein/kg/day for an individual weighing 70 kg. In fact, these theoretical figures are still well below the levels that some athletes consume, with values between 4 – 6.2grams/kg./day not being unusual.
There are very few studies on the effects of an increased protein intake upon strength and muscular development that show any kind of consistent evidence.
Lemon (23) cites a study by Celejowa and Homa (1970) that observed a negative nitrogen balance in 5 out of 10 male weightlifters who consumed about 2g/kg/day. However, one of these athlete’s negative nitrogen balance could have been as a result of an overall low energy intake. This data would suggest that 40% of the study group’s protein requirements were well in excess of the reference nutrient intake (RNI).
This increased requirement may be the result of increased oxidation, or of an increased rate of protein breakdown and/or synthesis, promoted by the exercise stimulus. Strength exercise does not stimulate amino acid oxidation relative to rest, which is in contrast to endurance exercise where oxidation occurs. Owing to the anaerobic nature of strength training the use of amino acids as a fuel source is minimal, the major fuel being CHO. Therefore, these higher protein requirements are not as a result of increased fuel utilization whilst training.
Despite these findings, in studies of strength training, athletes found that they went from positive nitrogen balance when they were on 1.6g/kg/day to negative nitrogen balance on 0.8g/kg/day. This effect was seen even when the energy intake was maintained constant at 75.3kj/kg/day.
It would seem to indicate that strength athletes have protein requirements well in excess of the average athlete. Online personal trainers & trainers in general should have a good understanding of this.
This is especially true if the calorific intake is reduced, as is the case with bodybuilders/weightlifters trying to get down to a competing weight category. A strenuous training programme further exacerbates the situation, as there will be high-energy expenditure.
As can be seen from the figures above, there is little evidence to support the high levels of protein that some athletes consume. One reason for the commonly-held belief ‘the more protein I eat, the bigger and stronger I’ll get’ may simply be the placebo effect.
Is a high positive nitrogen balance the answer?
It is also feasible that maintaining a highly positive nitrogen balance in conjunction with a strength-training regime is the best way to maximize strength and increase gains in muscle mass.
Some studies have supported this hypothesis of the high nitrogen balance. Lemon (23) reports on several such studies.
In one, Consolazio et al (1975) made observations over a 40 day period of training in which protein intakes of 2.8 g/kg/day vs 1.4 g/kg/day were consumed. The higher intake group achieved a nitrogen balance of 32.4 g vs 7.1 g. Furthermore, the higher intake group produced greater gains in their lean body mass (3.28 kg vs 1.21 kg).
Romanian weightlifters who increased their protein intake from 2.2 g/kg/day over several months of strength training,
Applied Nutrition – reported quite impressive gains. A 6% increase in lean tissue was achieved as well as a 5% strength gain.
Fronterra et al (1988) supplemented strength-training athletes by 0.33 g protein/kg/day on top of their normal dietary intake and found enhanced gains in thigh muscle over a 12-wekk period. Although the mass was increased, there were no strength gains compare to training alone. It may have been the additional energy intake that influenced these results, and not the fact that additional protein was being consumed.
These studies on the whole would tend to support the beliefs and methods of many strength athletes: that large intakes of protein are necessary to maximize strength and size gains. The data would suggest that consuming the amount of protein recommended in the Government’s dietary reference values would be insufficient for strength/size gains. It would appear that at this level of intake the amino acids available for growth would be insufficient.
However, as Lemon (23) comments, there appears to be a ceiling effect to the growth stimulation of additional protein.
A protein intake of greater than 2.4 g/kg/day results in no further enhancement of protein synthesis.
There is a suggestion that intakes of protein greater than 40% of total energy intake might be the upper limit (108).
A California personal trainer will be well aware of the scientific evidence, which shows that high protein intake is beneficial to muscular growth, but the benefits seem to diminish far below the levels that some athletes consume. If you are working with a strength athlete or someone trying to bulk up, the data would tend to indicate that 2 g/kg/day would be a good starting point. If you are going to use this figure as a benchmark, then a couple of other aspects need to be quite closely monitored.
You must ensure that the diet is balanced and adequately caters for the athlete’s overall calorific needs. Remember that, if this is not the case, any additional protein will be used to produce energy.
You may find that some fat is laid down as well as lean tissue. Measure the athlete’s body fat before starting this regime, and closely monitor it every 3 – 4 weeks to ensure that lean tissue is being laid down and not fat.
The athlete must be training sufficiently hard to produce a stimulus for growth. Just eating extra protein will not achieve the desired goal by itself.
SHOULD ATHLETES USE AMINO ACID SUPPLEMENTS
As has already been discussed;
Proteins are the cornerstones of many metabolic pathways and actions and all proteins are built from amino acids.
Athletes have an increased need for protein over and above that stated by the Government’s RNI value.
Individual amino acids have specific roles to play within the body and exercise affects their utilization e.g. BCAA for energy and glutamine within the immune system.
But is there any value in supplementing with individual or combination ns of certain amino acids to balance out their increased usage during exercise, or resulting from the stresses imposed by exercise?
The following section summaries a review article in Sports Medicine by Kreider et al 1993 (25).
The supplementing of individual amino acids has become more popular with athletes over the past few years. A lot of evidence has been amassed regarding the amounts of protein that are required for individual exercise modalities. However, less work has been carried out on what effect the relative quality of the protein has on performance.
Do all amino acids have to be present or are some required in greater quantities than others?
Are the metabolic and physiological responses to endurance and strength training affected by specific amino acids?
It has been established that strength athletes require a larger intake of protein than other athletes do. Strength athletes have suggested, for a long while, that amino acid supplementation may promote anabolism, on the grounds that enhanced tissue synthesis will produce greater strength gains. The whole hypothesis is based on a reported increase in growth hormone (GH) when patients received intravenous administrations of amino acids. However, this may not be valid.
Increases in growth hormone may not promote increases in muscle mass in non-deficient muscle. Neither may it enhance the effects of resistance training (23).
Intravenous administrations of amino acids may not produce the same results as when taken orally as the gastrointestinal tract will be involved.
Generally, there is support for both arguments within the literature, with most authors seeing a need for further research. As with a lot of aspects of sports nutrition the message seems to be that there is a lot of variability in response to dietary regimes amongst individuals and it is a case of finding what works within safe working guidelines.
Are they cheap? Protein powders are certainly more cost effective than vegetables, nuts, cheeses, fish and most beef products, as a source of protein per pound spent. However, they are not cost effective when compared to milk, powdered milk, pork, chicken or eggs.
Of course, one problem with these cheaper sources of natural protein is that they contain a high proportion of fat when compared to the powders.
It is because of the perceived value for money, and the fact that they are so easy to prepare, protein powders have remained popular with athletes, even though the justification for their use may be poorly researched.
Tipton and Wolfe (118) state that, ‘Using typical body composition techniques to measure changes in lean body mass, it would take approximately 1 year before any effect of dietary supplement plus resistance exercise training could be distinguished from resistance training alone’. Consequently, performance of an endpoint study of training plus dietary supplementation would require year-long control of each subject’s diet, exercise, and other lifestyle variables before any effect of dietary supplement was likely to be detected. This is a salutary thought when considering claims made by supplement manufacturers.
Protein hydrolysates are now very much the in vogue form of protein supplement and account for a large share of the market. They have been used clinically for the enteral feeding of patients and are a source of pre-digested protein. Enzyme hydrolysis is preferred over acid hydrolysis which results in the loss of tryptophan cysteine, threonine and serine and the conversion of glutamine and asparagines into glutamate and aspartate respectively.
Some manufacturers claim that, compared to dietary protein, hydrolysates have demonstrated a quicker absorption time and improved utilization. This, however, is not supported by any documented peer-reviewed literature. The evidence on the whole tends to be based on claims from sports personalities who have used them, or in-house research that is not published. Hydrolysates are typically priced anywhere from 2 -5 times that of normal protein powders.
The typical <strong><a href=”http://www.youtube.com/user/JAMCORE66?feature=mhee”> <i>California personal trainer’s</i></a></strong> recommendation is that protein is best obtained from natural sources. This is because protein from natural sources tends to be better utilized (99% of ingested protein being absorbed as amino acids.) With a supplement the absorption is not always as efficient. Where this is not practical, then the use of a whey concentrate/whey isolate mix may provide the best results.
The proposed ergogenic effect of amino acids is based on evidence that suggests that histidine, arginine, lysine, methionine, phenylalnine and ornithine may stimulate the release of insulin, GH and/or glucocorticoids. Although some studies have shown an increase in GH, mediated by the ingestion of certain amino acids, attempts to reproduce these results have been inconclusive. A series of experiments using ornithine and arginine dosages of up to 20 g/day showed that less than 10% of subjects were significantly affected by the supplementation regime. Those that did demonstrate any effect showed only a modest increase in growth hormone even though this was combined with heavy resistance training.