Should Different Athletes Consume Protein Differently?


Do I need more protein if I’m a bodybuilder? Do I need less protein if I’m a marathon runner? These are valid questions, as athletes participating in various activities manipulate their intakes of carbohydrates, fat, and protein differently to achieve their goals. The simple answer is that protein is key in optimizing the performance of all types of athletes and anyone who exercises, offering numerous advantages when consumed at levels above the recommended daily allowance (RDA). Some studies even show that athletes can benefit from as much as twice the RDA (1).

Athletes can be categorized into three main groups based on the goals associated with their chosen activities: endurance athletes, high-intensity athletes, and strength athletes. Endurance athletes include those who participate in activities requiring stamina, such as distance runners, swimmers, cyclists, and triathletes. High-intensity athletes compete in activities that require short, intense bursts of energy focusing on technique, lasting from seconds to only a few minutes. Such athletes include sprinters, volleyball players, and gymnasts. Like high-intensity athletes, strength athletes also engage in activities that require short bursts of energy. However, their primary goal is to attain strength and muscle mass rather than honing a sport-specific skill. The term strength athlete is synonymous with bodybuilder. 

Protein has been shown to boost performance among the three categories of athletes in the following ways:

1. Endurance Athletes 

Endurance athletes engage in low to medium intensity activities that elevate the heart rate for prolonged periods. To generate the energy needed to sustain low intensity exercise over a long duration, the body mainly uses the aerobic system—a system relying on the cardiovascular system to supply oxygen to the muscle. Improving endurance in athletes demands optimizing aerobic energy production, improving cardiovascular fitness, and maximizing the ability of muscle fibers to contract. 

Historically, much more attention has been paid to carbohydrates in maximizing endurance than protein. “Carb-loading” is a popular dietary strategy used by endurance athletes to improve performance, and involves eating foods high in starch prior to events in an effort to maximize muscle glycogen. Glycogen is the storage form of carbohydrate that can be used by the aerobic system to supply muscles with energy. With importance placed on carbohydrate consumption in endurance activities, protein is often pushed to the wayside. Many myths regarding protein intake have circulated among endurance athletes, such as the idea that high protein intake will cause bulky muscle gains that hinder efficiency, or that high protein intake is of greater relevance to strength athletes. 

However, strength and endurance athletes each have similar protein needs, with the only difference being how the body uses the protein in relation to different training regimens. While the protein consumed by strength athletes is primarily used to build muscle, it is used by endurance athletes for muscle repair and other functions related to the effects of prolonged training. Because protein improves endurance performance in a variety of ways, false beliefs resulting in low protein intake are detrimental to the athlete. 

2. High-intensity Athletes

High-intensity athletes seek to perfect technique and train their muscles to perform the powerful functional movements necessary to their sport. They engage in activity that consists of repeated bouts of short intense exercise. Such activity draws on the anaerobic system to make energy. 

In contrast to the aerobic system, the anaerobic system is able to make muscle energy in the absence of oxygen. Although this system is able to rapidly produce the energy needed to drive intense bursts of activity, it cannot be relied upon for extended periods of time—less than a 2 minute maximum. 

The primary goal of high-intensity athletes is to improve performance by perfecting technique and increasing speed, strength, and agility. This requires developing muscle memory for optimally performing a sport-specific movement. It also requires increasing the speed and force with which a muscle contracts, optimizing the lean muscle to fat ratio, and raising the anaerobic threshold. Supplying the body with adequate protein is essential for improving the performance of high-intensity athletes, as protein plays a key role in muscular development and fat loss, and may even beneficially influence factors that affect the anaerobic system.

Protein is the primary substrate used by muscle to achieve the optimal physical adaptations that enhance high-intensity performance. Following a strenuous workout, the body is very sensitive to the effects of protein in stimulating muscle synthesis. Eating protein during the post-exercise period promotes the synthesis of new muscle fiber proteins and an increase in contractile muscle proteins, resulting in greater strength and speed (2). 

3. Strength Athletes

Strength athletes share the same goal as high-intensity athletes in improving strength, but they place a particular emphasis on aesthetics, seeking to achieve optimal muscular proportion while maximizing muscle size and definition. 

Because lifting weights primes the muscles for growth, resistance training is the central component in the work-out regimen of the strength athlete. Like high-intensity athletes, strength athletes draw on the anaerobic system to get the energy they need to fuel their grueling resistance workouts. High protein intake has always been a central component of the dietary strategy used by strength athletes, as they have long recognized its value in promoting muscle synthesis. 

In addition, the beneficial effects of protein in promoting fat loss and preserving muscle is extremely important to strength athletes, who desire a particularly high lean muscle to fat ratio in achieving their aesthetic goals. Although all athletes will benefit from using dietary strategies to maximize muscular development and body composition, this is particularly important to strength athletes. 

Timing, Type, and Source of Protein for Any Athlete 

Following intense exercise, the body is very sensitive to the effects of protein in provoking muscle synthesis. Studies suggest that there is an optimal window during which maximal benefits can be derived from eating protein. Most experts agree that protein eaten close to the end of a workout provides the greatest benefit, especially within an hour after finishing exercise. However, some benefit has even shown to be derived up to 2 hours post-exercise (1, 3). 

An optimal amount of protein is needed to maximally stimulate muscle growth. Studies have shown that a dose of about 18 to 40 grams (depending on body weight, age, and workout length and type) is necessary to trigger muscle synthesis, although no greater benefit is derived from consuming amounts above this level in one sitting (2). 

To optimize muscle growth and repair throughout the day, studies suggest that several meals consisting of about 30 grams of protein each should be eaten throughout the day (3).

Whey Protein

Whey protein, derived from milk, is superior to other protein sources for promoting muscle growth and repair. It is absorbed faster than either casein or soy protein and is higher in BCAAs, ultimately leading to greater muscle synthesis (1, 3). In addition, its high leucine content serves as a trigger for muscle growth. Whey is also the most satiating protein, helping achieve fat loss and an improved body composition.

With the numerous advantages conferred by protein, and whey in particular, incorporating this macronutrient into a dietary and training plan will help any athlete get a leg up on the competition:

  • Whey is classified as a fast-absorbing protein. It is absorbed faster to maximize peak muscle growth for high-intensity and strength athletes.
  • Compared to other protein sources, whey is higher in BCAAs. BCAAs serve as a trigger for muscle growth after resistance training exercise. 
  • Whey protein enhances recovery after exercise because it elicits a higher insulin response that speeds up glycogen resynthesis.
  • Enhanced recovery from whey protein enables greater training volume to support increased muscle growth or more frequent training.
  • Whey protein stimulates greater fat oxidation following a test meal compared to other protein sources like casein or soy.

Although the goals and training techniques used to improve performance varies by athlete, protein has unanimous benefits among all athletes and exercisers of any kind and should be a central component of any good dietary strategy. 


  1. Phillips SM, Van Loon LJ. Dietary protein for athletes: from requirements to optimum adaptation. J Sports Sci 2011;29 Suppl 1:S29-S38.
  2. Cribb PJ, Hayes A. Effects of supplement timing and resistance exercise on skeletal muscle hypertrophy. Med Sci Sports Exerc 2006 Nov;38:1918-25. Doi: 10.1249/01.mss.0000233790.08788.3e
  3. Phillips SM, Tang JE, Moore DR. The role of milk- and soy-based protein in support of muscle protein synthesis and muscle protein accretion in young and elderly persons.J Am Coll Nut. 2009 Aug;28:343-54.

Interview with Dr. Phillips on Whey Vs. Soy


Based on years of research, Dr. Phillips says whey is superior to soy for muscle in aging adults.

Skeletal muscle is the tissue of action, movement, force, and function. Unfortunately, time takes a toll on bodies and on muscle mass. The combination of perceived energy decline, decreased physical activity, and a blunted response for muscle growth (“anabolic resistance”) forms the association between aging and a loss in muscle mass.

Sustaining this important tissue is a battle that Stuart Phillips, PhD, FACN, FACSM, professor at McMaster University in Ontario, Canada, has dedicated his career and his research to explore. On April 25, Dr. Phillips presented a comprehensive review of the research on dietary protein and aging at Experimental Biology 2012, in San Diego. The conference is an annual event where six scientific societies hold their joint scientific sessions and yearly meetings.

Deeming whey as the frontrunner in the race for the optimal protein supplement for aging adults, Dr. Philips explained that whey’s muscle-retaining benefits are clearly beyond those offered by soy (and other protein sources). Whey protein, he said, is uniquely superior for muscle stimulus and retention. Concluding his inquiry into protein for healthy aging, Dr. Philips explains that protein quality, quantity, and timing act synergistically to aid in the pursuit for long-term quality of life.

Isagenix caught up with Dr. Phillips at the event and afterward to gain more insight from his research. Taking a few moments to share the fruits of his pursuits, Dr. Philips tips his hat to whey protein:

Isagenix: What first interested you in studying the effects of protein on muscle?

Dr. Phillips: I was an athlete all my life playing hockey, football, rugby, and enjoying everything from swimming to triathlons. So muscle has always been near and dear to my heart (no pun) and my passion. I don’t compete in sports much anymore except with my wife and my three boys (13, 10, and 7), who are my stiffest competition yet! So now it’s about staying healthy, active, and maintaining my muscle mass, strength, and health. High-quality protein is a big part of that.

Isagenix: Can you explain anabolic resistance in aging? How does it relate to sarcopenia?

Dr. Phillips: Anabolic resistance is, as we define it, the inability of skeletal muscle in aged persons to mount a full protein synthetic response similar to that seen in the young. In other words, older people just don’t put the protein they eat into their muscles as efficiently as young people. That means as we age  our muscles gradually begin to make less protein so our muscle mass declines, otherwise called sarcopenia.

Isagenix: Based on your research, how does whey compare to other proteins like soy for building muscle?

Dr. Phillips: Soy is an excellent high quality protein as its PDCAAS (protein-digestibility corrected amino acid score) would suggest. In fact, if you use the PDCAAS scoring system the way it’s used now, then isolated soy is the ‘same’ as whey and casein. In reality, however, whey is a superior protein for repairing and gaining muscle, which is something we’ve shown in several studies now (1-4). In fact, milk proteins in general are better than soy for promoting lean mass, or muscle, gain (2; 3).

Isagenix: Why does the evidence suggest whey protein is superior to soy (or other proteins) in aging adults for promoting muscle gains or holding on to muscle?

Dr. Phillips: Our work, and that of other research groups also, suggests that it’s the high leucine content of whey protein, which is an amino acid highly stimulatory for muscle protein synthesis and muscle growth. That along with all of the other ‘essential’ (i.e., we need to eat them because we cannot make them ourselves) amino acids are present in just the right quantities to support an optimal rate of protein accretion.
Dr. Phillips discusses superiority of whey protein for muscle as we age.

Isagenix: How do higher doses of whey protein help overcome anabolic resistance in aging to slow/reverse sarcopenia?

Dr. Phillips: We’re not entirely sure, but we’re proposing that as people age their muscles become desensitized to the effects of the amino acid leucine. However, if you consume higher quantities of protein or you consume proteins higher in leucine like whey, then you ‘overcome’ (or at least minimize) the anabolic resistance of aging and slow sarcopenia. I’d never say you could reverse sarcopenia, but good food choices and good high-quality proteins, along with physical activity, are a big part of slowing it down.

Isagenix: Why is it important to distribute large doses of protein throughout the day?

Dr. Phillips: We’ve conducted two dose-response studies in young men after resistance exercise (5), and recently in older men with their muscles at rest and also following resistance exercise (6). The young men require 20 grams of protein to maximally stimulate new muscle protein addition to their muscles whereas the older men needed more protein, double the dose in fact, or 40 grams, to achieve a maximal stimulation. (Editor’s note: Recently, Maastricht University researchers found that 35 grams of whey protein also showed significant increases in muscle protein synthesis compared to 20 grams or 10 grams in older men. See article here.)

Thus, if we think about getting this maximal stimulation throughout the day, then what we want to have happen is that we should eat, if we’re young, 20 grams of protein per meal and 40 grams per meal if we’re older. Currently, North Americans consume protein in a very imbalanced fashion with about 6 grams coming at breakfast, 12 grams at lunch, and 60 grams at dinner; that’s not the best way to hang onto your muscle mass.

Isagenix: How does exercise play a role in helping overcome anabolic resistance?

Dr. Phillips: Exercise brings back the sensitivity that is lost as we age. In a sense, exercise, for a short-time, ‘reverses’ aging. In fact, what it really does is reverse the effects of inactivity, but oftentimes aging and inactivity are one and the same. So even aged muscle, when exercised, becomes sensitive to leucine and other amino acids again.

Isagenix: What would you suggest to older people as a way for them to help hold on to muscle with age?

Dr. Phillips: 1) Exercise and get some form of physical activity every day; 2) Consume protein at levels higher than the current RDA; 3) Consume three equal protein-containing meals throughout the day with at least 20 to 40 grams of high-quality protein; 4) it should maybe go without saying, but fruits, vegetables, and dietary fiber are also important – I like the DASH [eating plan], for example, but with more protein.
For more information about this topic and other health and wealth related topics use the following websites:

References (as supplied by Dr. Phillips)

1. Burd NA, Yang Y, Moore DR, Tang JE, Tarnopolsky MA and Phillips SM. Greater stimulation of myofibrillar protein synthesis with ingestion of whey protein isolate v. micellar casein at rest and after resistance exercise in elderly men. Br J Nutr 1-5, 2012.

2. Hartman JW, Tang JE, Wilkinson SB, Tarnopolsky MA, Lawrence RL, Fullerton AV and Phillips SM. Consumption of fat-free fluid milk after resistance exercise promotes greater lean mass accretion than does consumption of soy or carbohydrate in young, novice, male weightlifters. Am J Clin Nutr 86: 373-381, 2007.

3. Josse AR, Tang JE, Tarnopolsky MA and Phillips SM. Body composition and strength changes in women with milk and resistance exercise. Med Sci Sports Exerc 42: 1122-1130, 2010.

4. Tang JE, Moore DR, Kujbida GW, Tarnopolsky MA and Phillips SM. Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men. J Appl Physiol 107: 987-992, 2009.

5. Moore DR, Robinson MJ, Fry JL, Tang JE, Glover EI, Wilkinson SB, Prior T, Tarnopolsky MA and Phillips SM. Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men. Am J Clin Nutr 89: 161-168, 2009.

6. Yang Y, Breen L, Burd NA, Hector AJ, Churchward-Venne TA, Josse AR, Tarnopolsky MA and Phillips SM. Resistance exercise enhances myofibrillar protein synthesis with graded intakes of whey protein in older men. Br J Nutr 1-9, 2012.