2009 Studies & Research Blog

In most matters of fitness, it seems that any debate between different techniques or methodologies always boils down to some sort of oppositional dichotomy.  Inevitably, two opposites come to the forefront of the argument.  The examples are countless: Bulking vs. Cutting. Push vs. Pull. Upper vs. Lower. Full body vs. Body part splits.  Low-intensity, steady state cardio vs. high-intensity interval training.  Just as athletes are always striving to build the biggest, fastest, or strongest bodies they can, there is a constant push to find the most effective training methods to allow an efficient pursuit of one’s goals.  But when you think about it, it makes sense - who wants to waste time with techniques that don’t work when there are better alternatives available?  Certainly not me, and no one I can think of fits this description either.

One other popular debate that often arises involves the type of muscular contraction that is performed as the stimulus in strength training.  Muscles in the body can be contracted in three ways: concentrically, eccentrically, and isometrically.  In concentric contractions, the length of the prime mover muscle is shortened as it provides more force than the resistance, as in the lifting phase of a dumbbell curl.  In eccentric contractions, the length of the prime mover lengthens, as it works to slow a resistance that has a larger force output, as in the lowering phase of the aforementioned dumbbell curl.  And lastly, in an isometric contraction, the length of the muscle remains the same as it pushes against an immobile object.

While all three of these contractions stimulate muscle fibers, concentric and eccentric contraction are used more frequently than isometric contraction, and thus, a debate has emerged as to which method is more effective for strength training.  In order to clear up the debate, the August 2009 issue of the British Journal of Sports Medicine investigated the advantages and disadvantages associated with concentric and eccentric exercises.

Because muscles have the ability to attain higher absolute force during an eccentric contraction then a concentric one, many believe that eccentric contractions are superior in terms of building strength, as such exercises would provide a larger stimulus to the working muscles.  Despite this popular assumption, though, this new research indicated that when the intensity of training was comparable for eccentric and concentric contractions, the gains in total strength gained were not significantly different.  According to the data, strength gains with eccentric training were only superior to concentric training when the intensity was higher during eccentric training.

However, when gains in muscular size were compared, eccentric training proved to be superior, both when intensity of training was the same in both groups and when the eccentric group worked at a higher intensity.  Additionally, eccentric contraction adaptations seemed to be closely related to velocity.

Based on this research, eccentric contraction may be superior for building muscle size alone, but is not necessarily better for building strength.  In any case, a combination of the methods seems worthwhile, if only for the sake of variety.

SOURCE:

1. Roig, M., et al. The effects of eccentric versus concentric resistance training on muscle strength and mass in healthy adults: a systematic review with meta-analysis. The British Journal of Sports Medicine, 2009; 43:556-568

It’s no secret that resistance training has a number of benefits. However, despite the advantages associated with it, this method of exercise still seems to be suffering from the effects of a stereotype that supposes any amount of weight training will result in a big, bulky figure. Contrary to popular belief, this is not true. Although many women resist weight training because they feel the activity will result in a more manly physique, those fears are unfounded. Men and women have physiological differences that prevent women from adopting the same build as men.

In addition, many men will avoid resistance training because they are just trying to "slim down" or "tone up." What they fail to realize is that resistance training isn’t just for bodybuilders. In fact, an individual is not going to acquire a big and buff physique unless a consistent caloric surplus is maintained. But if one simply consumes their maintenance level of calories or just below, there will be positive changes in body composition (ie, less fat mass and more lean mass), but not a dramatic increase in muscle size.

Of course, there is also the misconception that resistance training isn’t a good idea for weight-management because it doesn’t burn very many calories. This could not be farther from the truth. In fact, an hour of vigorous weight lifting will burn about twice as many calories as an hour of treadmill walking at two miles per hour. In addition, resistance training raises one’s metabolism for many hours after the session is over, burning additional calories. Also, muscle mass itself requires quite a few calories to maintain, so the more muscle one has, the faster his metabolism will be. And last but certainly not least is the fact that research has shown that low muscle mass is associated with "clustered metabolic risk" - a condition that puts one at a higher susceptibility for cardiovascular disease and obesity-related disorders (1).

Perhaps the biggest obstacle to adopting a resistance training program, though, is the fear that it will take a very considerable commitment to achieve any results. But just like all of the aforementioned ideas about fitness, this belief is mistaken as well. In fact, a study published recently in the journal Medicine and Science in Sports and Exercise found that positive benefits of resistance training can come in a surprisingly short amount of time. The six-month study found that just 11 minutes of resistance training resulted in a "chronic increase in energy expenditure." In other words, metabolic rate didn’t just increase during the sessions; resting metabolic rate increased by more than seven percent, and the data also indicated increased fat oxidation (fat burning) (2).

Given this new data, there’s really no reason not to begin resistance training. In less than the time it takes to watch half of a television show, you can significantly increase you resting metabolic rate and increase your likelihood of burning fat for energy.

SOURCES:

1. Steene-Johannessen, Jostein, et al. Low Muscle Fitness Is Associated with Metabolic Risk in Youth. Medicine and Science in Sports and Exercise, 2009; 41(7): 1361-1367

2. Kirk, Erik P., et al. Minimal Resistance Training Improves Daily Energy Expenditure and Fat Oxidation. Medicine and Science in Sports and Exercise, 2009; 41(5): 1122-1129

In the world of fitness, it seems as though many people have exercise attention deficit disorder.  Simply put, as soon as some people begin on exercise routine or protocol, they’re already on the lookout for a new one.  Often, exercisers just don’t give their plans enough time and become frustrated at the lack of results.  What they don’t realize is that changing one’s body is more of a marathon than a spring - most alterations are made gradually, and visible evidence of progress can take a long time to develop.  For this reason, a perfectly good workout scheme can gain a bad reputation simply because not enough time or effort was put into the program.  Of course, some programs are poorly designed and aren’t going to deliver lasting results no matter how much dedication one displays.  For just as there are fad diets, fad exercise routines exist, popping up like weeds yet promising that the grass is greener.

At first glance, pylometric training may appear to be one of these fad workout plans.  After all, pylometric training is relatively new and doesn’t quite adhere to traditional strength-training procedures.  One major difference is that pylometric training involves rapid, explosive movements, rather than the slow, sustained lifting and lowering phases that characterize most strength or mass gain programs.  Additionally, pylometric training uses minimal, if any, added weight, relying instead on body weight and momentum to provide the stimulus for developing muscular strength.  And often, pylometric exercises mimic moves used in sports, whereas most weight-lifting exercises aren’t direct translations of athletic movements.

Despite these differences, though, pylometric training is quite powerful, and research has shown that it can be as effective, if not more so, as traditional strength training protocols.  For example, a study from the latest issue of the Journal of Strength and Conditioning Research compared the effects of twelve weeks of a pylometric training routine with those of a traditional strength training program.  The pylometric training consisted of three sessions per week, with exercises such as drop jumps and hurdle jumps.  The traditional training was also performed three times per week and included endurance, core stability training, knee extension and flexion and hip adduction and abduction.

After the twelve weeks, the pylometric training proved to be valuable.  Although the pylometric group had a lower average score in the countermovement jump than the traditional training group at the beginning of the study, the pylometric group ended up outperforming the traditional group by more than 3 centimeters in that jump at the end of training.  In addition, the pylometric group increased depth jump height by 18 percent, while the traditional training group actually performed worse in this assessment after the twelve weeks.  And these measures of explosive strength were not the only category in which the pylometric training produced the most positive changes; the protocol also improved contraction speed more than traditional training.

So if you’re tired of traditional training and want an alternative that can offer increases in explosive strength or improvements in sports performance, pylometric training may be for you.

SOURCE:

Campo, Silvia Sedano, et al. Effects of lower-limb plyometric training on body composition, explosive strength, and kicking speed in female soccer players. Journal of Strength and Conditioning Research, 2009; 23(6): 1714-1722

Most athletes, whether they are training for strength, speed, skill or a combination of all three, will agree that the work you do during training sessions has an enormous impact on how much progress you make toward your goals. Whether you’re trying to alter your body composition or increase your aerobic or anaerobic endurance capacity, the harder you work, the better off you’ll be. As a result, a lot of the focus in the fitness world is on creating more efficient and effective workouts, such as replacing steady state, low-intensity cardiovascular exercise with high-intensity interval exercise. Obviously, this has its advantages. But another key aspect that some people forget about is recovery. The more intense your workouts become, the more your body will need adequate rest for recovery and growth.

Much like training, though, there are many options for recovery. Some trainers and athletes advocate complete rest - no extraneous activity between sessions, to minimize the possibility of overworking muscles. Meanwhile, others will recommend some form of active recovery, usually low-intensity exercise, to ensure that optimal blood flow and nutrient exchange continues.

Studies have shown that active recovery has its advantages, usually when performed in between sets or exercise sessions performed on the same day. One study investigating the effects of active recovery versus passive recovery found that participants were able to produce a significantly higher mean power output after an active recovery session when compared to passive recovery. Additionally, those engaging in active recovery had a higher level of oxygen uptake than those engaging in passive recovery (1). The extra oxygen taken from the bloodstream for use by the muscles most likely drove the improvements in power.

Other research has shown that active recovery has additional advantages over passive recovery. Another study compared passive recovery, short-term body massage, and active recovery after cycling trials. Again, the active recovery was indicated by researchers as the best method, as it provided the highest level of lactate removal (2).

Active recovery is suited for a variety of sports and athletic events, as another study investigated its use in rock climbing. Even in just 20 minutes, active recovery proved to be better at lowering lactate levels. In addition, researchers noted that cold water immersion of the affected muscles was an effective recovery method as well (3).

SOURCES:
1. Bogdanis, Gregory C., et al. Effects of active recovery on power output during repeated maximal sprint cycling. European Journal of Applied Physiology and Occupational Physiology, 1996; 74(5): 461-469.
2. Gupta, S., et al. Comparative study of lactate removal in short term massage of extremities, active recovery and a passive recovery period after supramaximal exercise sessions. International Journal of Sports Medicine, 1996; 17(2): 106-110.
3. Heyman, Elsa, et al. Effects of Four Recovery Methods on Repeated Maximal Rock Climbing Performance. Medicine & Science in Sports & Exercise, 2009; 41(6): 1303-1310.

The alarming rise in obesity has been linked to many factors, from an increase in non-nutritive sweeteners in many food products to the reduction in physical activity and nutritional knowledge of individuals.  Those who cite the lack of physical activity as the main reason for increasing obesity levels point to modern entertainment, such as television and video game systems, as some of the worst offenders, as they keep people, especially children and teens, on the couch instead of outside playing sports.

However, advances in video game technology, specifically motion-detection devices, have led to systems such as the Nintendo Wii, which allow gamers to actively participate in their virtual adventures using their entire bodies instead of just their thumbs. But are these video game systems, engaging though they may be, a suitable substitute for actual exercise?  A study recently published in the Journal of Exercise Physiology investigated that very question.

The study compared the efficacy of three scenarios - sedentary (traditional) video game playing, Boxing on the Nintendo Wii system, and treadmill walking at 2.5 miles per hour.  The participant group included both males and females with an average age of 31.5 years.  Heart rate, oxygen uptake and ratings of perceived exertion were taken at rest and during the exercise sessions.  The researchers also surveyed the participants for hedonics, or liking, of the activities, which is crucial for exercise programs because it influences continued compliance.

The results indicated that all of the activities - even the sedentary video game playing, triggered an increase in heart rate and oxygen uptake.  However, in both of these categories, the Nintendo Wii boxing simulation provided the greatest increase.  Average heart rate for participants in the Wii boxing game was 121.2 beats per minute, nearly 30 beats per minute more than the next highest activity, the treadmill walking.  In terms of oxygen uptake, which is linked to energy expenditure, the Wii boxing simulation provided an increase of about 50 percent over the oxygen uptake during treadmill walking.

The participants did seem to be aware that they were receiving a better workout from the Wii, as ratings of perceived exertion (RPE) were highest during the Wii simulation, with treadmill walking following behind.  But even though participants acknowledged that the Wii boxing required the most work, the liking rating of the Wii was highest as well, nearly double that of the treadmill walking.

And while the Wii boxing simulation would not produce as good of a workout as actual boxing, it’s not likely that the average person would have the choice between the two.  The researchers took this into consideration, noting that the prevalence of sedentary video game play suggested that the substitution of a more interactive video game could be a highly effective way to increase physical activity.  The high liking ratings also suggest that the Wii games would be less intimidating than exercise in a gym setting, and thus suitable for beginners.

SOURCE:

Barkley, Jacob E. and Penko, Amanda.  Physiologic Responses, Perceived Exertion, and Hedonics of Playing a Physical Interactive Video Game Relative to a Sedentary Alternative and Treadmill Walking in Adults. Journal of Exercise Physiology Online, 2009; 12(3): 12-23.

For many fitness enthusiasts, a pair of headphones is just as essential a piece of exercise equipment as a pair of dumbbells. Thanks to advances in technology that have driven down the cost and size of portable music players, being force to listen to whatever
is playing over the sound system at the gym is no longer necessary. It seems nearly every exerciser at the gym is supplying their own personal soundtrack via an iPod or similar device. While many feel that music has the ability to pump them up, there has been little scientific research exploring the possible beneficial effects of music on the body and exercise performance. Recently, though, the Journal of Exercise Physiology addressed this issue with a novel experiment.

The study included both males and females and the participant pool was broken into three groups: fast music, slow music, and no music, corresponding to what subjects would be listening to during the experiment. Regardless of what they were listening to, each of the groups participated in the same mode of exercise - steady state cardio with no incline. The researchers were unsure of the effects of the music, as it has traditionally been used more for relaxation than to augment athletic performance. In addition, previous research has yielded inconsistent results.

The subjects jogged for 15 minutes, with measurements for heart rate, stroke volume (the volume of blood ejected during one contraction), frequency of breaths, oxygen consumption (the amount of oxygen used by tissues during respiration) and cardiac output (the amount of blood pumped from a ventricle in one minute) taken every minute, beginning at the seventh minute of exercise. To ensure that these measurements were not affected by external factors, subjects were prohibited from exercising 24 hours prior to the session, and from consuming caffeine for four hours beforehand.

After compiling the statistics, the researchers found several striking differences between the fast, slow, and no music groups. Those listening to the music with a faster tempo displayed greater rates of oxygen consumption, cardiac output, stroke volume and frequency of breaths than those in the other two groups. In addition, systematic vascular resistance also decreased significantly. And while listening to music with a faster tempo appeared to increase the work of the lungs, there was no difference in blood pressure between any of the groups.

The researchers also pointed out that the increase in oxygen consumption also triggered an increase in caloric expenditure for the fast music group, suggesting that listening to high-tempo music during exercise can actually aid in weight management by burning more calories. Lastly, the researchers noted that "by acting as a positive influence on caloric expenditure, fast music may motivate the individual to increase adherence to exercise, allowing a greater caloric expenditure over time."

So put away the slow jams - for fast-paced fat burning, there’s a need for speed!

SOURCES:

Birnbaum, et al. Cardiovascular responses to music tempo during steady-state exercise. Journal of Exercise Physiology Online, 2009; 12(1): 50-56

It’s a common thought in the health and fitness world that those who are engaging in regular physical exercise have significantly higher BMR’s because of it.  For this reason, many people who are exercising feel they can eat a higher calorie diet because ‘they workout’.

If you find yourself in this mindset and eating more food because you believe you’re experiencing an increase in metabolic rate from working out, you may want to rethink that.

Recently a study was conducted by the clinical Epidemiology Program that assessed the effect of exercise training on resting metabolic rate in individuals with type 2 diabetes.

The study was designed to so that 103 participants (both male and female from 39-70 years of age) were divided up into four different groups.  Group one participated in aerobic training, group two was assigned to a resistance training protocol, group three was to perform combined aerobic training with resistance training, and group four was the control group who did not perform any exercise at all.

The subjects followed their specific exercise protocol for a period of 22 weeks during which RMR was measured by indirect calorimetry, 30 minutes after an overnight fast and body composition was assessed by bioelectrical impedance.

These measurements were taken when the study first started, at the 3 month mark, and then again after 6 months time had passed.  The results of the study demonstrated that the RMR did not change significantly over any of the groups even though there was improvements seen in peak oxygen consumption and muscular strength in those individuals who were doing the exercise program.

This study then demonstrates that while you may see good physical gains after participating in an exercise program, this does not necessarily mean your BMR (basal metabolic rate – the number of calories you burn during the day at rest) has increased by a significant amount.

Individuals who perform regular physical activities will have larger daily calorie needs and expenditures but this is mostly due to the calorie expenditure of the actual exercise session – not because of the exercise session.

So just don’t go adding a bunch more calories to your diet because you believe you’re boosting your metabolic rate or you could eventually find your body fat levels starting to go up.

Reference:
Alberga, A. et al. (2009). The Effect of Exercise Training on Resting Metabolic Rate in Type 2 Diabetes Mellitus. Med Sci Sports Exerc. Jun 30.

This isn’t your grandfather’s form of cardio. Recently, high-intensity interval training has surged in popularity, freeing fitness enthusiasts from long hours on the treadmill. HIIT is highly efficient, boosting the metabolism into a calorie-burning frenzy and challenging the
cardiovascular system. As a result, all types of athletes, from bodybuilders to basketball players, have adopted high-intensity interval training as a means to minimize time spent in the gym while maximizing endurance performance and improvements in body composition.

Unfortunately, though, high-intensity interval training is not without downsides. HIIT can be hard on the joints and can also diminish the body’s stores of glycogen, phosphocreatine, and adenosine triphosphate (ATP). Because of this, HIIT cannot be performed for long periods of time - which is great for those trying to save time, but can be an issue for those who are trying to burn a lot of calories. But the lack of glycogen, phosphocreatine and ATP can also interfere with other athletic pursuits, such as weight lifting or sports. So is there any way to soften the blow?

According to recent research from the Journal of the International Society of Sports Nutrition, there is, and it’s as close as your nearest supplement store. What is this magical endurance aid? Beta-alanine. Beta-alanine is classified as a non-essential amino acid, and interestingly, is not believed to be used in the building of proteins. This amino acid is usually not ingested on its own unless it is supplemented; rather, the most common sources are the dipetides carnosine, anserine and balenine. While these are contained in fish, beef and chicken, the amount of beta-alanine from those sources is not sufficient to trigger the results of the following study (1).

In the study, forty-six college-aged men who had not taken supplements within the past six months participated in two three-week programs of high-intensity interval training and either placebo or beta-alanine supplementation. Fitness assessments were taken prior to the program to find a baseline, and also at the midpoint and end of the study.

Even after only the first three weeks, several significant changes were noted between the beta-alanine group and the placebo group. Those supplementing beta-alanine demonstrated longer time until exhaustion and improved maximal oxygen consumption (VO2 Max). Additionally, the increase in Total Work in the beta-alanine group was nearly double that of the placebo group. The supplement group also experienced positive changes in lean body mass, while the placebo group did not (2).

While high-intensity interval training can be helpful on its own, beta-alanine supplementation appears to increase the positive effects as well as improve work capacity, making your training more effective than ever before.

SOURCES:

1. Beta-Alanine. The Facts. http://www.betaalanine.info/

2. Smith, Abbie E., et al. Effects of [beta]-alanine supplementation and high-intensity interval training on endurance performance and body composition in men; a double-blind trial. Journal of the International Society of Sports Nutrition, 2009; 6(5): 5

When it comes to physical training, the mind can be a very powerful thing.  You’ve probably experienced this yourself a number of times before.  For example, recall an instance when you felt fully motivated and ‘pumped’ to get into the gym.  How did the performance go on that day? Likely, you pushed hard – possibly even set some new personal bests.

Now recall a time when you felt like you had to drag yourself to the gym, feeling like you’d rather be anywhere but working out.  How was your performance that day? Chances are you would have been better off staying home.

While there are obviously going to be factors that influence how your body feels going into a workout (sleep, nutritional status, overall stress level, length of time from last workout, etc), your mental state can really influence the overall performance you see.

Recently researchers wanted to look at the perceived influence of caffeine on workout performance.  Many people already know that caffeine is said to be a substance that enhances performance and as such, you’ll find it in many of the popular sport and energy drinks available.

The study was designed to look at the variables of number of reps performed, rate of perceived exertion (RPE), blood pressure (BP), and peak heart rate (PHR) during resistance training exercises.

The issue of caffeine was factored in by dividing the subjects into two different groups; one group that was told they would ingest a 250 ml beverage containing 3 mg/kg caffeine and the other told they would ingest a 250 ml placebo beverage without caffeine.

The twist of the study however was that neither of the beverages contained caffeine, therefore it was measuring the change in performance of the subjects who simply thought they were taking caffeine (hence looking at the placebo effect or the power of the mind).

The results of the study indicated that the group who believed they had consumed caffeine completed a total of two more reps for each exercise, had a lower level of RPE, and there were no substantial differences in peak heart rate across the two groups.

Therefore, from this study we can conclude that in some cases, simply thinking that you’re taking a stimulant is enough to actually produce better performance gains.  The question then needs to be asked, could mental training, that is teaching oneself how to mentally boost yourself up before a workout, have its own place in your muscle building workout program?

Perhaps one of the key aspects that distinguish those who really reach new limits with their training and those who progress but to not nearly the same extent is partially an issue of mental state along with their body genetics and training/diet habits.

Reference:

Duncan, MJ, et al. (2009) Placebo effects of caffeine on short-term resistance exercise to failure. Int J Sports Physiol Perform. Jun;4(2):244-53

Sometimes, it seems like the BCAAs - leucine, isoleucine, and valine - get all the attention in the world of sports nutrition. But is that really fair? While BCAAs do aid in recovery and prevent catabolism, other amino acids shouldn’t be forgotten. One in particular, carnitine, is just beginning to get more attention, as recent research has indicated that it has a variety of properties that would potentially be useful for strength and endurance athletes.

As an amino acid, carnitine plays a role in muscle-building, but also in transporting fatty acids through the body to areas where they can be used for energy. Additionally, carnitine aids in the process of fat oxidation, the conversion of fatty acids into fuel. And while your body can synthesize carnitine, the amount produced is often less than required for active individuals. In order to see whether increased amounts of carnitine could boost exercise performance, scientists provided the amino acid to subjects over the course of a resistance training program.

The program in the study consisted of both compound and isolation exercises for the lower and upper body. The individuals in the study were also asked to record their total calorie counts as well as protein, carbohydrate and fat intake to provide the most accurate data. Additionally, the study was double-blinded and placebo-controlled.

At the close of the study, there were significant differences between the carnitine and placebo groups. Those supplementing carnitine produced greater peak power, with improvements of up to 15.7 percent compared to the placebo group. In addition, the rate of decline in power was lower with the carnitine group, suggesting improvements in endurance.

The improvement in endurance was likely also related to the lower lactate levels found in the carnitine group - measurements taken post-exercise found that those taking the supplement had lactate levels up to 16.2 percent lower than the control group. As a result of these findings, the researchers concluded that carnitine supplementation "may significantly enhance anaerobic work capacity" in athletes.

While carnitine is present in red meat and dairy products, the quantities present in these foods may not be sufficient enough to stimulate the results found in this study, so a supplemental form of carnitine would be appropriate. Earlier studies have suggested that carnitine supplementation can also increase VO2 Max, increase muscle glycogen stores, and improve recovery from exercise. It is also believed to have potent effects for weight loss. So even if you haven’t heard bout carnitine, that doesn’t mean it isn’t worth hearing about.

SOURCE:

Jacobs, Patrick L., et al. Glycine propionyl-L-carnitine produces enhanced anaerobic work capacity with reduced lactate accumulation in resistance trained males. Journal of the International Society of Sports Nutrition, 2009; 6(9)

Chances are, if you walk into any gym and ask ten people what they think the most important supplement in their arsenal is, nine will probably offer the same response - whey protein. At some point, whey was crowned the king of protein supplements, most likely due to its high bioavailability and low fat and carbohydrate content. As a result, most strength athletes make it a staple supplement, without even thinking why - and that’s a problem.

Despite what Joe Bro and most of the supplement industry will tell you, whey protein is not the best source of protein. Alarming, I know. And the grand irony of the entire situation is that the very feature that is touted as whey’s best aspect is actually the reason it is ineffective. This characteristic is whey’s rapid absorption. While speed has its advantages in some cases, whey protein is just a bit too quick. In fact, almost 60% of it can be oxidized by your liver for glucogenesis, meaning it never reaches your muscles (1). Simply put, the speedy absorption of whey makes it ineffective at battling catabolism (muscle breakdown).

The only way that scientists were able to make whey effective at preventing catabolism was to administer two grams of it every 20 minutes for seven hours; this slow delivery proved to be more than three times better at fueling muscles than a single dose (2). Unfortunately, that’s not a realistic option. So what’s the solution? A protein blend, preferably one with micellar casein, egg albumin, and other sustained-release proteins.

Studies have shown there is a "synergistic effect between solubleproteins and caseins," meaning that a combination of protein sources is superior. Combining a slow-digesting protein source such as casein with whey provides a steady stream of amino acids for utilization by the muscles; one group of researchers specifically noted that whey’s "too-rapid dietary amino acid delivery cannot support the anabolic requirement" in the post-workout period (3).

By contrast, the sustained delivery of a protein blend yields much better results. One study found that using a blended protein supplement in conjunction with exercise resulted in twice the drop in body fat percentage, twice the gains in lean mass, and twice the gains in strength compared to whey and exercise (4). Given this information, the choice is clear - you can either work twice as hard with whey, or ditch the broscience and let a blend do the work for you.

SOURCES:

1. Jungas RL, et al. Physiological Review, 1992: 72: 419-448.

2. Biorie Y, Proceedings of the National Academy of Sciences of the United States of America, 1997: 94 (26): 14930-5.

3. Lacroix, Magali, et al. The American Journal of Clinical Nutrition, 2006: 84(5): 1070-1079.

4. Demling, Robert H., and DeSanti, Leslie. Annals of Nutrition and Metabolism, 2000: 44:21-29.

Note: The following study was performed with SciVation Xtend as the source of BCAAs.

A randomized, double-blind study was performed to evaluate the efficacy of consuming a supplement containing branched-chain amino acids (BCAAs) during an eight-week resistance-training program.

Thirty-six strength-trained males with a minimum of two years resistance-training experience (25.5 yrs, 177.7 cm, 85.2 kg and 9.3 % body fat) were randomly assigned to receive either 14 grams of BCAAs (n=12), 28 grams of whey protein (n=12), or 28 grams of carbohydrates from a sports drink (n=12) while performing an eight-week resistance-training program.

Participants followed a periodized, whole-body training program that involved training all major muscle groups once per week using a four-day training split. Subjects body weight, body composition, and 10-rep max on the bench press and squat were determined before and after the eight-week training program. Subjects followed a standardized diet while following the program.

All groups had a 100% compliance with the study protocol. The BCAA group experienced a significantly greater gain in body weight than the whey group (2 ± 1 kg vs. 1 ± 1 kg; p < 0.02) and the carbohydrate group (2 ± 1 kg vs. 1 ± 1 kg; p < 0.01). For lean mass, the BCAA group gained significantly greater lean mass than the whey group (4 ± 1 kg vs. 2 ± 1 kg; p < 0.01) and the carbohydrate group (4 ± 1 kg vs. 1 ± 1 kg; p < 0.01).

The whey group also gained significantly more lean mass than the carbohydrate group (2 ± 1 kg vs. 1 ± 1 kg; p < 0.02). BCAA group decreased their percent body fat significantly more than the whey group (2 ± 1 % vs. 1 ± 1 %; p = 0.039) and the carbohydrate group (2 ± 1 % vs. 1 ± 1 %; p < 0.01).

Muscular strength was significantly greater in the BCAA group on the 10-RM bench press than the whey group (6 ± 3 kg vs. 3 ± 2 kg; p < 0.01) and the carbohydrate group (6 ± 3 kg vs. 2 ± 2 kg; p < 0.01). For the squat, the BCAA group gained significantly more strength on their 10-RM than the whey group (11 ± 5 kg vs. 5 ± 3 kg; p < 0.01) and the carbohydrate group (11 ± 5 kg vs. 3 ± 2 kg; p < 0.01).

Ingestion of a supplement containing BCAAs while following an 8-week resistance training program resulted in a greater decrease in percent body fat, an increase in lean mass, and 10-RM strength gains on the bench press and squat vs. ingestion of a whey supplement or a sports drink. In addition, the ingestion of a whey protein supplement resulted in greater lean mass gains than ingestion of a sports drink.

Check out Bodybuilding.com’s full line of BCAAs right here.