The Science of Protein

Why take protein?

Protein is required for anabolic activity; repair and replacement of damaged proteins (caused by oxidative stress of high energy turnover and mechanical disruption) after intense resistance or endurance based exercise.

Muscle Protein Synthesis (MPS) and muscle protein degradation are opposing processes present during and after exercise that acutely fatigues muscles to the point of failure (i.e. maximal).

Protein Synthesis >> Protein Breakdown only when protein/ amino acids are available after exercise.

Net protein balance needs to be positive for anabolic adaptation (muscle growth) and recovery for improved performance to take place following training sessions. Adaptation mechanisms (mTor master regulator of MPS, and AMPK/ Alpha PGC-1) remodel proteins in muscle, bone, tendon to better withstand stress imposed by training. Proteins repair multiple components of physiology; cells, tissue, cells, mitochondria, synthesis of enzymes and support optimal function of immune system, which all rely on ingested protein rich in leucine and other essential amino acids (EAAs) to trigger MPS.

An adequate amount of protein should be available after feeding to allow for increased muscle protein synthesis and hypertrophy, otherwise muscle degradation (protein breakdown) and post-exercise catabolism occurs, causing muscle wasting which ultimately leads to over-training syndrome or even worse debilitating conditions. Muscle is a dynamic tissue, constantly being created or destroyed, and is dependent on its use. Strength and endurance training is by far the most effective way of influencing body composition in performance cyclists. This is extremely important for Master athletes who are experiencing sarcopenia and muscle wasting.

Muscle repair and growth activity is greatest after exercise and relies on protein availability, and is dependent on intensity and the amount of protein, EAAs present. Increasing the stimulus of MPS through frequency of training maintains a higher rate of MPS if enough protein is taken. There is a lower net muscle secretion (i.e. loss of nitrogen), and gain of lean mass.

The effect of protein on muscle growth is better understood for strength training sessions rather than after endurance workouts. As previously discussed, an interference effect exists between strength and endurance training when performed concurrently and so careful planning of sessions should be considered along with optimal nutrition strategies.

How much protein and when?

MPS depends on the amount of protein taken and when it is taken over the duration of a day. When fasted overnight, net protein balance turns positive after eating food, to help stimulate MPS.

The timing of windows for ingestion of protein have been determined through evaluating the balance between protein synthesis and protein breakdown in a few studies. Maintaining the number of times MPS is in positive balance is important for muscle repair and hypertrophy, especially in weight restricted and power limited cyclists.

We must remember that gaining power is much more preferential than losing weight, along with lean mass. Adding lean mass leads to greater power, improves glycogen storage (40% greater muscle glycogen can lead to a 1/3 longer duration at threshold), is associated with a lower percentage body fat and is ultimately healthier long term. The latter also suggests that higher lean mass individuals are more efficient fat metabolisers, which is an important element of cycling economy.

Maintaining or preserving lean mass at least, in most situations, is the fundamental reason for good recovery nutrition. Interestingly, protein intake before exercise may prime MPS through an increased pool of readily available amino acids straight after exercise, to remodel muscle.

Recommended doses of protein have been established:

1.2-1.4 g/kg/ day for endurance training individuals

1.2-1.7 g/kg/ day for strength/ and endurance training individuals.

However, optimal amounts and timing of when to take protein have been established. Total daily intake of 80g of protein through three different time formats has been studied:

2 x 40g every 6h

4 x 20g every 3hrs

8 x 10g every 1.5hr over 12hrs.

4 x 20g (every 3hrs) proved to be superior for stimulating MPS over a 12hr period maximising the number of times the athlete is in positive net protein balance. This format demonstrates the highest total MPS vs protein breakdown.

Is more better?

40g of protein has been shown to increase MPS by 56% vs none (control), whereas 10g dietary protein only increases by 28% vs control.

20g of high quality protein every 3/4hrs (including post-exercise) is regarded as an optimal amount to increase MPS during the day. Adding a further 40g of protein before bedtime is known to increase MPS during sleep and prevent protein breakdown by increasing net protein balance. This addition tends to boost the recommended amount per individual to 1.5g/kg/day making this daily target easier to achieve and preventing muscle breakdown at a critical time.

This would result in 4/5 evenly spaced meals of 0.25- 0.35g/kg per meal over 16h at approximate 1.25-1.5g/kg/ day

Supplementation

Having enough protein available should be determined on a needs basis. Whether an individual is performing intensive endurance, strength exercise, or both (concurrently) will determine their protein requirements as described above. Lean food should be prioritised first… then a high quality commercial protein supplement (such as whey isolate) second to that, although in reality many people reverse this advice, taking the supplement first.

Practically and for convenience sake, taking a supplement is easier when preparing adequate meals is not feasible. Weight restricted individuals with deficiencies or aging individuals with anabolic resistance to resistance training and amino acid intake may wish to increase protein intake throughout the day, favouring a supplement just to meet the desired frequency of intake.

Strength & Endurance: Protein & Carbohydrate in recovery.

In both scenarios, adding extra carbohydrate to a protein meal has no further benefit on MPS if protein intake is at an optimal dose of around 1.2g/kg/day. The exception to this may be high GI carbohydrates or simple sugars. Similar is true for increasing glycogen re-synthesis, the ACSM recommendation is 1 – 1.5g/kg of carbohydrate over 30 min at 2hr intervals up to 6hrs post exercise.

Co-ingesting protein has little effect on the rates of muscle glycogen storage if carbohydrate intake is already at the maximum. Optimising protein intake after either endurance or strength training seem to have interchangeable dosing regimens. Protein intake is considered ideal during and after exercise, multiple times on consecutive days which provides greater benefit for higher body mass individuals/ high lean mass individuals and increased recovery rate.

A periodised approach to protein and carbohydrate intake, is a practical strategy in response to mode/ intensity of exercise during a concurrent training regimen. Carbohydrate fuelling is only worthwhile before exercise if duration is greater than 1 hr or of high intensity, otherwise protein consumption may be a better choice. Restoration of glycogen levels should be complete quickly if a second bout of exercise is to be performed within 3 hours of the last for additional overload or anabolic effect. However it may be necessary to start an endurance session in a glycogen depleted state to promote fat metabolism and amplify the adaptation signal to exercise.

What types of protein are available?

Long endurance sessions followed by resistance workouts warrants the co-ingestion of dietary protein with carbohydrate to restore glycogen levels and preserve or promote net muscle balance, as explained above. After resistance exercise there is increased sensitivity to dietary protein for the following 24hr, which limits the use of the body’s own proteins, to prevent catabolism and muscle wasting.

Digestion and absorption of a high quality dietary protein results in a peak blood amino acids concentration, greatest one hour after ingestion. This may be sustained for up to 2-3hr depending on protein type.

Amino acid appearance studies show the bioavailability of three types of proteins, with their blood plasma profiles tracked over a three hour timeframe, with their kinetics from baseline.

Whey, casein and soy protein isolates each different characteristics for release and absorption (digestibility) and their individual behaviour impacts on MPS and muscle growth. Generally, bioavailability and amino acid release into the blood is fast, intermediate and slow for whey, soy and casein respectively. It is also thought that speed of ingestion determines increased Leucine and amino acid integration into muscles.

Whey (the gold standard of protein supplementation) is the most commonly known in resistance training circles and is commonly used in research, as a high quality protein with essential amino acids including Tryptophan which is important for brain health, cognitive function and sleep. Whey protein is a naturally formulated dairy protein (as a concentrate, isolate or hydrolysate which may remove associated lactose and fats) rich in leucine, important for triggering MPS. Evidence suggests 1.5 grammes of leucine is needed to be ingested as a threshold to trigger. Whey protein is a slow release, less soluble gel, although absorbed quickly which increases amino acid availability for longer, and hence extended MPS.

Soy protein is a vegetable protein (soy lecithin) isolated from the soya bean, has better palatability than whey protein, but only an intermediate amino acid release profile with high levels of arginine and glutamine. Soy is a complete protein meaning that it contains adequate proportions of essential, non-essential and conditionally required amino acids to support normal muscle turnover. These alpha-amino acids are important precursors of proteins and mediators important for immune function, blood flow (Nitric oxide nitro-dilators affected by beetroot), and growth hormone release. Soy protein may have cardiometabolic benefits as low doses (25g) have been associated with reduced LDL (considered bad carriers of fats) cholesterol. Even though many of the allergenic components of soy protein are removed during processing of the soya bean, soy protein products may still illicit allergic reactions in some individuals.

Casein protein is another isolate from dairy products, which has a slower release profile and is less rapidly broken. The gel like quality acts to maintain delayed release of amino acids which overtime the optimal windows for protein intake, keep MPS turned on. Some evidence suggests that casein may be more beneficial when taken before bed.

Although faster release of amino acids help stimulate MPS, a sustained release and extended amino acid supply will maintain MPS for longer. For this reason a combination of the three individual proteins, or a blend could be the best of all worlds. In fact soy protein can act as a ‘bridge’ protein between whey and casein proteins and hence may have advantages over more popular single whey isolate preparations.

Ultimately the choice of protein preparations should boil down to the individual choice; the individuals body composition status, change in body composition objectives and the severity of an exercise programme, degree of concurrent exercise and practical preference for intake.

Optimising a workout strategy:

Perform endurance exercise in the morning, after overnight fasting. Complete endurance training with a low energy state to maximise adaptation.

Optimise protein ingestion, 4 x 20g throughout the day and immediately post exercise , a further intake of 20g protein may be optimal for maximising MPS if done within first 3 hours after exercise.

Avoid high carbohydrate intake during low intensity long duration exercise bouts.

Restore carbohydrate/ protein with a mixed meal prior to resistance (strength) exercise to ensure positive energy status.

Post resistance sessions, achieve adequate protein availability to increase Muscle Protein Synthesis and maintain throughout the day through protein pulsing and mixed meal for appropriate restoration of glycogen stores with carbohydrate which may help preserve muscle mass and promote faster MPS.

Use protein preparations such as whey, or triple (whey, soy and casein) blends on a needs basis only. A food first approach should be followed at all times. Supplementation after initial protein intake will help achieve recommended doses and intake of adequate muscle and health promoting BCAAs.

Soy protein is an intermediate releasing vegetable protein with cardiometabolic benefits, and can be allegenic in some people. Casein is slower releasing and is used later in the day before bed to maintain MPS and anabolic effect during sleep.

Choice

The market is flooded with vast amounts of protein supplements touting to be better than the rest for x number of reasons. What is obvious, if you are training intensively, either endurance, strength or even concurrent sessions in the same day then maintaining adequate protein intake without some form of supplementation (in addition to real food) will be difficult. I have personally used and highly recommended Scitec products to my clients as an excellent and trusted source of ultrafiltered whey protein concentrate/ microfiltered whey protein isolate. I can disclose that I have no financial incentive to promote Scitec nutrition or any of its products through Scitec Direct except for receiving an occassional tub for personal use.

Through an informal collaboration with Scitec direct I am pleased to offer a 10% discount on their products using the ‘CPSIM10‘ promotion discount code applicable to the shopping basket.

Myomax Hardcore provides an excellent source of essential and branched chain amino acids in its unique BCAA express matrix formula, with adequate components of Arginine (3g/ serving), Leucine (over 5g/ serving), Glutamine (almost 14g/ serving), tryptophan and taurine among the complete amino acid profile. The protein matrix is mixed with Palatinose a low glycemic index isomaltulose for controlled glycogen restoration post exercise. This product can include a multicomponent Creatine matrix, if desired, for added benefit of increasing the ATP pool during exercise and facilitating its reconstitution after intense sessions. So far performance gains for strength and aerobic capacity and lactate threshold have been anecdotal with no formal research. However there is increasing recreational evidence of benefit for endurance athletes using similar products for more effective training.

PLEASE NOTE: I suggest you do not stick to the recommended dose as per their serving size and customise your own dosage based upon the infomation I have provided above. That way you will get many more servings per tub and lasts much longer. Please do not hesitate to email me if you want any further direction based on your individual circumstances.