Protein powders and shakes


A few decades ago, protein powders used to lurk in gyms and so-called “health” food stores. They were stacked neatly on shelves amidst colourful ads that lured would-be buyers with images of famous bodybuilders and athletes whose physiques few of them would ever match. In those days, their primary targets were body builders. Claims varied, but most brands promised increased muscle gain that, according to the ads, run of the mill, food derived protein could not possibly provide.

Today, protein powders have escaped the confines of gyms and health food stores and have become ubiquitous on food market shelves, in pharmacies, and virtually anyplace else food, supplements, or pharmaceuticals are sold. Their user base has changed dramatically to include athletes (professional sports people who are not bodybuilders), recreational athletes (sport hobbyists and/or fitness enthusiasts), and lifestyle users (consumers who think protein powders are healthy snacks and/or will help them lose weight)(1). Vegetarian and vegan consumers of protein powders tend to fall in the last two categories and are likely to believe the powders, or other similar supplements, are necessary to meet their daily protein needs. Some users claim they “feel better” and have more energy when they consume protein powders, while others simply believe that without their daily dosage, their muscles would vanish into thin air.

ENERGY

“The extra protein gives me energy!” is a claim I hear surprisingly often. It is surprising because protein is a lousy source of energy. It is a last resort the body will tap when it runs out of its preferred fuel (particularly during exercise): glycogen (aka stored carbohydrate)(2). You may have heard of athletes engaging in something called “carb-loading” before events. This consists of consuming a higher ratio of carbohydrates to help the body handle the energy requirements of extended activity, particularly if the event involves increasing pace and effort to beat the competition (3). The more intense the exercise, the more carbohydrate the body burns. Consuming carbs before and during exercise helps athletes keep up the pace. In fact, a high carbohydrate diet increases endurance time three-fold when compared to a high protein diet (3). Once glycogen runs out, so does your energy and ability to keep going. Similarly, failing to replenish your glycogen stores after exercise, will impair your ability to recover and achieve your training goals.

During periods of extended low intensity exercise, such as walking, fat becomes an important source of energy, more so if you engage in regular exercise. The more you train, the more your body uses fat for energy when you are resting or performing less strenuous activities. As you pick up the pace, your body switches back to using glycogen.

Image source:  McArdle et al. – Sports and Exercise Nutrition, 3rd Ed., Chapter 5, Macronutrient Metabolism in Exercise and Training, page 157 (3).

In a nutshell, if you’re looking for extra energy, put away the protein powder and have some healthy carbs instead.

MORE MUSCLE

Muscle growth occurs as the result of training, not from the overconsumption of protein. There is only so much protein the body will use before it stores the excess away. Protein powders are digested faster than food derived protein, making protein available for muscle repair in a more expedited manner. “Aha!” you might say, “so, they ARE good for something!” Well, not really. In the long run, the end result is about the same – except, perhaps, for your wallet.

Studies looking at the effects of supplementation and strength training combined show insignificant or no difference between placebo and control groups (2,4).  In their 2009 joint position paper on nutrition and athletic performance, the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine concluded the following (5):

“Current evidence indicates that protein and amino acid supplements are no more or no less effective than food when energy is adequate for gaining lean body mass. Although widely used, protein powders and amino acid supplements are a potential source for illegal substances such as nandrolone, which may not be listed on the ingredient label.”

In other words, as long as you meet your body’s protein requirements, it doesn’t make much difference if you’re getting the protein fast, from a powder, or slower, from food. What matters most is timing (6). Consumption of protein and carbohydrate containing foods immediately after training is far more important if you want to see results. The sooner you eat, the better. Letting as little as two hours pass after a workout without eating will lead to a lot of disappointment on your part if you’re looking to build muscle mass (7).

PRE-, DURING and POST-EXERCISE NUTRITION

For best results in terms of performance and overall health (the latter is sometimes overlooked when people consider a plan of action in the short term), remember that supplements are not a replacement for healthy food choices.

Eat breakfast, consume the appropriate amount of calories for your body (don’t forget to eat healthy fats), stay hydrated and be sure to eat before and after exercise. If you like coffee or tea, you may be surprised to know that caffeine is an effective ergogenic aid, particularly in racing events, but also in short term, high intensity events, if consumed one hour before exercise (8,9). If you’ve given up coffee and tea because you think it will hinder your performance, dehydrate you, or interfere with electrolyte balance, you may want to reconsider your choice (8,9,10).

While studies on the effects of protein restriction on performance have yielded inconclusive results, the same is not true when it comes to carbohydrate restriction which has been shown to be detrimental (11,12). The importance of carbohydrate consumption after workouts can not be overemphasized. The aforementioned position paper on nutrition and athletic performance provides the following guidelines for performance athletes (5):

  • Carbohydrate recommendations for athletes range from 6-10 g/kg (2.7-4.5 g/lb) body weight per day depending on extent and duration of exertion (5).
  • Protein recommendations for endurance and strength trained athletes range from 1.2-1.7 g/kg (0.5-0.8 g/lb) body weight per day. The authors stress that food sources can easily meet requirements and supplementation is not necessary (5).
  • Fat intake should range from 20%-35% of total energy intake. Note that consuming less than this will not improve performance (5).
  • Before exercise, a meal or snack “should provide sufficient fluid to maintain hydration, be relatively low in fat and fiber to facilitate gastric emptying and minimize gastrointestinal distress, be relatively high in carbohydrate to maximize maintenance of blood glucose, be moderate in protein, be composed of familiar foods, and be well tolerated by the athlete.”(5)
  • During exercise, it is important to replace fluid losses and “provide carbohydrates (approximately 30-60 g per hour) for maintenance of blood glucose levels.”(5)
  • After exercise, “a carbohydrate intake of ~1.0-1.5 g/kg (0.5-0.7 g/lb) body weight during the first 30 minutes and again every 2 hours for 4 to 6 hours will be adequate to replace glycogen stores. Protein consumed after exercise will provide amino acids for building and repair of muscle tissue.”(5)

To put things in perspective, let’s consider the nutritional requirements of a 160 pound male professional soccer player:

Calories: approx. 4,000 per day
Protein: approx. 110 grams per day, or 11% of daily calories
Carbs: approx. 640 grams per day, or 64% of daily calories
Healthy Fats: approx. 111 grams per day, or 25% of daily calories

Notice that although 110 grams of protein per day represents quite a bit more than the amount of protein recommended for weekend athletes or sedentary persons, this amount does not represent a higher percentage of daily calories. In other words, it is not added (or supplemented) protein.

BOTTOM LINE

If the only way you are meeting your protein requirements is by supplementing with protein powders, there is something wrong with your diet. It should not be difficult to meet the recommended 10% to 15% of your daily calories in the form of protein. In fact, I would be very surprised if this is the case, given the abundance of food varieties available in North America. In the unlikely event you are not getting enough protein or the necessary ratios of essential amino acids, tweaking your diet will be better for your health (and for your wallet) in the long run than starting a protein supplementation habit.

REFERENCES

  1. Overview of the Sports Nutrition Market—Food, Beverages and Supplements, 2010; ISSN 1920-6593 Market Analysis Report, AAFC No. 10745E.
  2. Maughan RJ. Nutrition in Sport – Volume VII of the Encyclopedia of Sports Medicine. MA: Blackwell Science, Inc.; 2000.
  3. McArdle WD, Katch FI, Katch VL. Sports and Exercise Nutrition, 3rd Ed. MD: Lippincott Williams & Wilkins; 2009.
  4. Williams AG, van den Oord M, Sharma A, Jones DA. Is glucose/amino acid supplementation after exercise an aid to strength training? Br J Sports Med, 2001;35:109-113.
  5. Nutrition and athletic performance. Journal of the American Dietetic Association, 2009; 109(3):509-527.
  6. Poole C, Wilborn C, Taylor L, Kerksick C. The role of post-exercise nutrient administration on muscle protein synthesis and glycogen synthesis. Journal of Sports Science and Medicine, 2010;9:354-363.
  7. van Essen M, Gibala MJ. Failure of protein to improve time trial performance when added to a sports drink. Med Sci Sports Exerc. 2006;38:1476-1483.
  8. Cox GR, Desbrow B, Montgomery PG, Anderson ME, Bruce CR, Macrides TA, Martin DT, Moquin A, Roberts A, Hawley JA, Burke LM. Effect of different protocols of caffeine intake on metabolism and endurance performance. Journal of Applied Physiology, 2002:93:990-999.
  9. Paluska SA. Caffeine and exercise. Current Sports Medicine Reports, 2003;2:213-219.
  10. Bell DG, McLellan TM. Effect of repeated caffeine ingestion on repeated exhaustive exercise endurance.  Medicine & Science in Sports & Exercise, 2003; DOI: 10.1249/01.MSS.0000079071.92647.F2
  11. Knechtle B, Knechtle P, Mrazek C, Senn O, Rosemann T, Imoberdorf R, Ballmer P. No effect of short-term amino acid supplementation on variables related to skeletal muscle damage in 100 km ultra-runners – a randomized controlled trial. Journal of the International Society of Sports Nutrition, 2011;8:6.
  12. Ivy JL, Res PT, Sprague RC, Widzer MO. Effect of a carbohydrate-protein supple- ment on endurance performance during ex- ercise of varying intensity. Int J Sport Nutr Exerc Metab. 2003;13:382-395.
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