2009 Studies & Research Blog

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

A recent study compared two creatine dosing protocols and looked at 24 hour urine excretion of creatine and methylamine. Subjects took 5 grams of creatine 4 times a day for five days and the other trial had subjects taking 1 gram 20 times a day. The more frequent lower dosing protocol showed significantly less creatine was excreted in the urine when compared to the higher dosing protocol.

While it’s likely unrealistic to dose 1g of creatine 20 times a day, this study does give important insight into lower more frequent dosing being the optimal method of creatine supplementation. One of the more recent findings of creatine supplementation is  we no longer need the loading(20gram) a day phase and can establish the same muscle creatine concentrations at 30 days, when using a much lower dose of 3 grams a day.  Since many of us our now are utilizing these much lower dosing strategies( 3-5g) a day, it would be interesting to see a study compare 5 grams a day, taken one time, or the same dose broken up into various doses and then look at urinary excretion.

It has been postulated that the CREAT transporter has limited capacity and ingesting large amounts of creatine at one time overwhelms its uptake ability, allowing much of the creatine to get metabolized and excreted in the urine. The other area of interest when looking at the reasons why smaller dosing may be more beneficial, is the faster downregulation of the CREAT transporters that the larger and less frequent doses of creatine may bring about compared to smaller more frequent dosing strategies.

Sale C, Harris RC, Florance J, Kumps A, Sanvura R, Poortmans JR.
Urinary creatine and methylamine excretion following 4 x 5 g . day(-1) or 20 x 1 g . day(-1) of creatine monohydrate for 5 days

By: ATHLETIC EDGE NUTRITION

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.

With so much attention given to protein and protein supplements, it can be easy to overlook the fact that carbohydrates and fats are also essential components to a healthy diet and the promotion of optimal performance.  In fact, insufficient intake of carbohydrates and fats will effectively render all of your protein supplements useless, as you won’t have the proper nutrition needed to exercise, recover and grow.  And just as there are protein supplements to make hitting protein goals more convenient, there are carbohydrate and fat supplements as well.

One of the most popular carbohydrate supplements is Waxy Maize Starch (WMS).  Waxy Maize Starch is a relative newcomer to the supplement market, and has been widely hailed for its rapid digestion and lack of taste, making it easy to mix in with other foods and beverages you may already be taking.  Additionally, WMS has the unique ability to bypass the stomach, allowing it to be absorbed directly into muscles, shuttling nutrients without the bloating sometimes associated with dextrose or maltodextrin.

While all this sounds great, there is one thing that really matters - does it work?  Despite the relatively short time in the spotlight, numerous studies have investigated the benefits of WMS.  When supplemented before exercise, WMS resulted in an increase of carbohydrate oxidation.  In addition to this, researchers noted that WMS had an ergogenic effect, with athletes showing an ability to perform more work during a performance exercise (1).

But pre-workout isn’t the only time when Waxy Maize Starch has proven effective as an alternative to other, more traditional carbohydrate sources.  As one might expect, the post-workout period, where many place an emphasis on the quickness of nutrient delivery to potentially depleted muscles, is a great window of opportunity for the advantages of WMS.  In one study, researchers compared a variety of types of carbohydrates on their abilities to provide glycogen resynthesis after exercise.  Even when pitted against classic bodybuilding favorites such as maltodextrin and resistant starch, Waxy Maize Starch stole the show.  WMS outperformed both of those alternatives, providing nearly double the muscle gylogen concentration of resistant starch (2).

And thanks to the lack of fat and sugars, Waxy Maize Starch delivers everything you want and nothing you don’t, ensuring that you can create your ideal post-workout recovery nutrition.

SOURCES:

1. Goodpaster, BH, et al. The effects of pre-exercise starch ingestion on endurance performance. International Journal of Sports Medicine, 1996; 17(5):366-72.
2. Jozsi, AC, et al. The influence of starch structure on glycogen resynthesis and subsequent cycling performance. International Journal of Sports Medicine, 1996; 17(5):373-378

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.

Step into any supplement shop and head on over to the protein section, and you’ll likely be faced with the same thing no matter where you are - a wall of whey. Whey protein seems to have cornered the market as far as bodybuilders are concerned, prized for its high bioavailability, rapid absorption, and convenient, powdered form. However, whey isn’t the only way to go - there are plenty of other powdered protein sources, such as egg and soy, the latter of which may, according to recent research, be preferable to whey, despite what supplement store shelves might indicate.

One reason whey protein is a favorite of athletes is its low cost. When purchased in bulk, such as 10lb containers, whey can cost as little as $.40 per serving. But even this cost isn’t preferable to soy protein, which often costs as little as $.36 per serving in 2lb containers. Even without the bulk discount, soy protein can be just as reasonably priced, if not more so, than whey (1,2).

Whey is also prized for its array of amino acids and easy digestibility, an area in which soy protein also ranks highly. While overlooked by many, "Soy protein is a complete protein that ranks right up there with the best in the Protein Digestibility Corrected Amino Acid Score (PDCAAS). Soy protein is generally very low in or free of fat, cholesterol, and lactose" (2). Additionally, soy may be preferable for those who are lactose intolerant, because unlike whey, it is not a dairy product. However, many whey protein products are lactose-free or have very low levels of lactose, so this may not be a very big concern.

The most common complaint against the use of soy protein is the fact that soy protein may raise estrogen levels. However, it should be noted that studies have shown that soy protein consumption may actually reduce estrogen levels - one group of researchers found that "estrone (a type of estrogen) levels were about 15 percent lower among women who consumed the highest amounts of soy protein" (3). Also noteworthy is that soy contains a number of "physiologically active compounds with cholesterol-lowering properties" (4).

In order to test the merit of soy protein in the realm of bodybuilding, researchers also pitted soy supplementation versus whey in a study of men undergoing a resistance training regimen. After 12 weeks of training, the group receiving soy protein and the group receiving whey protein displayed nearly identical improvements in body composition, with both experiencing increases in lean mass and reductions in body fat. Additionally, the two groups had very similar increases in strength over the course of the 12 weeks. As a result, the researchers concluded that "soy based protein supplements appear to be as effective as animal-based protein to support strength gains," and that prior research indicated "regular soy consumption improves lipid profiles and the insulin-to-glucagon ratio and lowers oxidative stress" (4).

Considering this strong body of research, it would seem that whey is not the only way - soy is a perfectly suitable alternative.

SOURCES:
1. Whey Protein Information and Product Listing, Bodybuilding.com: http://www.bodybuilding.com/store/wheyper.html
2. Soy Protein Information and Product Listing, Bodybuilding.com: http://www.bodybuilding.com/store/soy.html
3. Diet Rich in Soy Protein Lowers Estrogen: http://www.annieappleseedproject.org/dietricinsoy.html
4. DeNysschen, Carol A., et al. Resistance Training with Soy vs. Whey Protein Supplements in Hyperlipidemic Males. Journal of the International Society of Sports Nutrition, 2009; 6(8)

For those wishing to maximize the results of their efforts in the gym, the idea that fitness is a science as well as a sport is a familiar one.  Countless scientific journals, text books, and college courses continue to be developed regarding proper exercise technique and nutrition.  While the former has more universally accepted tenets, nutrition is a subject in which heated debates continue to rage.  One of the reasons the body of knowledge regarding sports nutrition is constantly expanding and evolving is due to the influence of supplement companies, who fund studies in an attempt to back the claims of their products.  But there are also studies that disprove their claims, leading to a cycle of scientific arguments back and forth.

Recently, a study was published that affected perhaps the most contested element of nutrition, at least in the bodybuilding world - what to consume post-workout for optimal recovery.  Countless products claim to be the best at this, despite the wide range of macronutrient profiles and ingredient lists.  Companies such as Cytosport argue that Muscle Milk is the best, with a blend of medium-chain triglycerides, protein and complex carbohydrates.  On the other end of the spectrum, the manufacturers of Gatorade claim that carbohydrates - specifically the simple sugars found in their product - are they key to recovery.  These claims were partly supported by a study published in the latest issue of the Journal of the International Society of Sports Nutrition, but suggested an even better recovery aid - cereal and milk.

It turns out that the staple American breakfast may in fact be the most important meal of your day, even if you’re not having it first thing in the morning.  The study pitted the ingestion of cereal and non-fat milk versus a carbohydrate-electrolyte beverage in the post-workout period, and measured plasma insulin, plasma lactate and glycogen and muscle protein levels.  After the exercise trials, the participants were fed either the cereal or the beverage, with measurements taken 15, 30, and 60 minutes afterward (1).

The results of the study indicated that cereal and milk was as good as, if not better than, the carbohydrate beverage in terms of muscle recovery.  Plasma insulin levels were significantly higher with the cereal, and levels of plasma lactate were lower with the cereal, indicating that it would be the better choice for delivering nutrients to muscles and reducing levels of lactic acid buildup (1).

Also worth noting is the higher levels of mTor phosphorylation in the cereal-consuming groups - this is the addition of a phosphate group to a protein, which is an important part in a number of bodily functions.  And due to the lower cost of cereal and milk than sports beverages and the superior supply of amino acids, the researchers concluded that the classic breakfast combination would be a preferable post-workout option (1).

SOURCES:

1. Kammer, Lynne, at al.  Cereal and Nonfat Milk Support Muscle Recovery Following Exercise.  Journal of the International Society of Sports Nutrition, 2009; 6(11)

Those familiar with the supplement industry are aware that most supplements are grouped into general categories, according to their supposed effects.  A few of the most popular groups are supplements intended to increase lean mass, those intended to decrease body fat, and those to increase strength.  And while many supplements concern themselves with one or maybe two of these categories, a multi-purpose supplement that targeted all three would be ideal.  According to recent research, that supplement might be HMB.

You’re probably wondering - what is HMB?  Good question.  HMB stands for beta-hydroxy-beta-methylbutyrate, which is a metabolite of leucine, an essential amino acid.  While it does naturally occur in certain foods, including alfalfa and catfish, some have surmised that supplementing HMB might be beneficial (1).

The first study investigating the effects of HMB on body composition and strength in conjunction with exercise was conducted in 2000.  While the study only lasted four weeks, the benefits of HMB were clear.  Groups receiving HMB supplementation experienced two times the reduction in body fat that the placebo group experienced.   The HMB group also experienced greater lean mass gains and strength.  The researchers concluded that "regardless of gender or training status, HMB may increase upper body strength and minimize muscle damage when combined with an exercise program" (2).

A study published this month in the Journal of Strength and Conditioning Research took the prior research a step further, investigating HMB’s effects throughout a nine-week exercise program.  The researchers noted that earlier research had not considered the effects on "resistance-trained" individuals, which may have accounted for the impressive results in past studies.  To counter this, the study participants were required to have at least one year of weight training experience.  The average level of experience was 3.9 years, suggesting that any growth from the study would be a direct result of the HMB, rather than so-called "noob gains" (3).

The findings of the study in regard to strength gains were curious; while one-repetition maximum in the leg extension increased by 9.1 percent on average, its effect on upper body strength was negligible.  The researchers did note, though that it was "possible that the 9-week study period was not long enough to establish the effect of HMB on gains in strength" (3)

The HMB supplementation seemed to have a greater effect in regard to body composition, though, as the HMB group members experienced a mean decrease in body fat percentage of 7 percent, while the placebo group only had a 1 percent decrease.  Additionally, the HMB group experienced greater gains in lean body mass than the placebo group (3).

So is HMB the ultimate supplement?  Not quite.  While it did boost strength it some lifts, it generated only negligible differences in others.  But it also had a positive effect on lean mass and body composition, so it may still be worth a look.  The researchers also noted that HMB seemed to be "more efficacious to individuals initiating resistance training programs and, possibly, also in less well-trained muscle groups," so more experienced lifters may not see the same benefits (3).

SOURCES:

1. HMB Supplement Review - BodyBuilding For You: http://www.bodybuildingforyou.com/supplements-reviews/hmb-supplement-review.htm

2. Panton, Lynn B., et al. Nutritional supplementation of the leucine metabolite ?-hydroxy-?-methylbutyrate (hmb) during resistance training.  Nutrition, 2000; 16(9): 734-739

3. Thomson, Jasmine S., Waston, Patricia E., and Rowlands, David S. Effects of Nine Weeks of ?-hydroxy-?-methylbutyrate Supplementation on Strength and Body Composition in Resistance Trained Men.  The Journal of Strength and Conditioning Research, 2009; 23(3): 827-835

The benefits of protein in muscle-building, via the contribution of amino acids, and fat loss, thanks to a high thermic effect, are common knowledge among the fitness community.  But this amazing macronutrient has a variety of other benefits that are unknown to many, and more are being discovered all the time.  For instance, a recent study from the Medical College of Georgia revealed that certain types of protein can actually help scientists identify cases of prostate cancer.

The study, published in the Early Edition of the Proceedings of the National Academy of Sciences, identified the beta-Arrestin2 protein as a way for scientists to assess whether cancer cells are developing in male reproductive organs, notably the prostate.  Additionally, increasing beta-Arrestin2 levels in the prostate may aid in the fight against prostate cancer for those who have the deadly disease.

According to the researchers, prostate cancer initiation and development is a result of an increase in androgen receptors in the prostate.  The increase in androgen receptors allows the cancer to develop by utilizing as much of the body’s available testosterone as possible.  Androgen receptors can also mutate, developing the ability to feed off of other growth factors in the body.  Because of this adaptability, prostate cancer is one of the most difficult cancers to defeat.

The researchers found that androgen receptors and beta-Arrestin2 seemed to have a relationship; when there was an abundance of androgen receptors, as in a cancerous prostate, there were low levels of beta-Arrestin2.  Thus, the researchers reasoned that the opposite would be true and tested the hypothesis by forcing an increase in beta-Arrestin2 levels.  The results were as expected - higher levels of beta-Arrestin2 suppressed the activity and expression of androgen receptors.

While this discovery alone is not enough to defeat prostate cancer, it does open the door for possible treatments, and could change the way prostate cancer is classified.  Additionally, the development of a treatment in the form of a molecule mimicking beta-Arrestin2’s suppression of androgen receptor activity is a goal of the researchers.

And while supplementation of beta-Arrestin2 isn’t an option at this point, this research shows that protein isn’t just for bodybuilders and fitness enthusiasts.  While amino acids do play an essential role in building muscle, cellular proteins keep the body functioning at all levels and are much more than simply a source of calories.

SOURCES:

1. Daaka, Yehia, et al. Identification of beta-Arrestin2 as a corepressor of androgen receptor signaling in prostate cancer.  Proceedings of the National Academy of Sciences Online Early Edition, 2009; 10.1073

2. Medical College of Georgia (2009, May 20). Protein That Suppresses Androgen Receptors Could Improve Prostate Cancer Diagnosis, Treatment. ScienceDaily. Retrieved May 26, 2009, from http://www.sciencedaily.com­ /releases/2009/05/090520100513.htm

Enter any gym in America and you’re bound to see two things, regardless of location - sweaty people and sports drinks.  Beverages such as Gatorade and Powerade are everywhere, boosted by celebrity endorsements from the likes of Tiger Woods, Vince Carter and Michael Jordan.  While an infusion of simple carbohydrates is undoubtedly helpful for athletes engaging in long bouts of high-intensity exercise, are sports drinks effective, or even appropriate, for the average gym-goer?  Studies seem to be split on the matter.

Recently, a study indicated that the most maligned ingredients in most sports drinks, simple sugars (such as glucose and maltodextrin), were actually a key to their effectiveness, regardless of whether they were digested or not.  Researchers prepared beverages containing glucose, maltodextrin or neither, so that they tasted identical, and gave them to athletes, who rinsed the drinks around in their mouths before spitting them out during exercise.  Despite not reaping the energizing effects of the carbohydrates in the drinks, the rinsing of the simple sugar mixes were shown to "significantly reduce the time to complete the cycle time trial," while the placebo drinks had no such effect.  The data was so impressive that the researchers concluded that "much of the benefit from carbohydrate in sports drinks is provided by signalling directly from mouth to brain rather than providing energy for the working muscle" (1).

However, simple sugars carry concerns as well, such as the risk of tooth decay. But it’s not just the sugars in sports drinks that increase this risk, researchers recently concluded.  The New York University School of Dentistry found that citric acid, commonly found in sports drinks, ate away at the enamel coating on teeth.  As a result, the drinks could easily leak into the bone-like material underneath, causing a weakening and softening of the tooth that could "result in severe tooth damage and even tooth loss if left untreated" (2).

So should you be drinking a carbohydrate-containing beverage during your workout?  There’s no clear yes or no answer.  If you’re trying to lose weight, it’s probably not the best idea, as liquid calories are unlikely to leave you sated and may negate the caloric deficit created by the exercise during which they were consumed.  But even those in mass-gaining phases may find them unnecessary.  Research indicates that the most important consideration may be the length of exercise.

According to researchers at the University of New Mexico, "unless a person is going to exercise for at least 90 minutes, consuming the carbohydrates is self-defeating."  While sports drinks containing carbohydrates may aid the body in absorbing water, there is no evidence that the body actually retains the water more effectively than if water were consumed on its own, and therefore is not more effective at battling dehydration (3).

SOURCES:

1. Chambers, E.S.  Carbohydrate sensing in the human mouth: effects on exercise performance and brain activity.  The Journal of Physiology, 2009; 587: 1779-1794.

2. NYUCD Study Finds Sports Drink Consumption Can Cause Tooth Erosion.  NYU Office of Public Affairs; April 7, 2009.

3. Felicia Fonseca. Study: Gatorade No Better Than Water. New Mexico Daily Lobo; March 4, 2004.

With the recent recall of Hydroxycut and the suspension of several NFL players due to their use of a weight-loss supplement, dietary aids have come under a lot of fire within the past few months.  Unfortunately, most of the general public is not very educated on this subject, and media reports can be exaggerated and blown out of proportion, leading the average consumer to think that all weight-loss drugs, or all dietary supplements in general, are unsafe or ineffective.  Research from the latest edition of the Journal Of Strength and Conditioning Research, however, tells a different story.

In the study, which was double-blinded and placebo-controlled to reduce the possibility of bias and maximize accuracy, participants were given a generic thermogenic supplement, containing typical ingredients found industry-wide, such as caffeine, niacin and capsicum extract.  An array of measurements were taken during four phases: 30 minutes of initial rest; 50 minutes of rest after supplementation; 60 minutes of light exercise (treadmill walking); and 50 minutes of recovery after exercise.

Researchers found several significant differences between the thermogenic and placebo groups. Energy expenditure, even at rest, was higher in the thermogenic supplement, with the biggest difference around the 50-minute mark.  During and after exercise, energy expenditure increased by as much as 11% when comparing the thermogenic group to the placebo group.

Another difference was found when the researchers measured oxygen consumption rate and respiratory exchange rate.  With the thermogenic supplement, there were significant increases in oxygen consumption, which in past studies has been linked to an increase in lipolysis - the breaking down of fat for energy.  And while blood pressure and heart rate increased slightly, the changes were not long term or harmful.

As a result, the researchers concluded that the thermogenic aid would be helpful in weight management.  However, they did note that it would be most effective when combined with exercise, and that due to side effects such as anxiety, nausea, dizziness and headaches, users should avoid consuming supplements with large (400-500mg) doses of caffeine.

In addition, the researchers cited prior research to suggest which ingredients might be most effective.  They noted that "caffeine, capsaicin, bioperine and niacin my increase EE [energy expenditure] and improve body composition" (1).

SOURCES:

1. Ryan, D., et al. Acute Effects of a Thermogenic Nutritional Supplement on Energy Expenditure and Cardiovascular Function at Rest, During Low-Intensity Exercise, and Recovery from Exercise. Journal of Strength and Conditioning Research, 2009; 23(3):807-817