Recent research has helped developers target sport-specific products. This includes some sports, such as golf, that traditionally have not been associated with nutrition-specific supplements.

Despite a shaky economy, properly marketed and targeted sports nutrition and energy products are still selling1, and scientists are churning out research on many novel ingredients and finding new applications for existing ones. Recent research also has helped develop specific categories within sports nutrition, including products targeted to enhance recovery and minimize muscle soreness, as well as sports-specific products for sports not typically associated with nutrition-specific supplements (golf, for instance).

Recovery is a hot topic among scientists jockeying to find ingredients that will buffer physiological processes that contribute to fatigue, enhance glycogen storage and mitigate muscle soreness and inflammation.


Beta-alanine

Beta-alanine stands out as the front-runner in this category. Beta-alanine is the rate-limiting substrate in the production of carnosine (composed of beta-alanine and histidine; histidine is never rate-limiting), which has antioxidant properties and works largely as a buffer to offset acid production in the muscle, thereby preventing fatigue2.  Carnosine is most highly concentrated in Type II, fast-twitch, muscle fibers3. Therefore, elevating carnosine through beta-alanine supplementation is most beneficial for those individuals exercising at a high intensity. In addition, supplementation may be especially effective for vegetarians who tend to have lower muscle carnosine content than non-vegetarians.

Research shows that an effective dose of 4-6g beta-alanine taken daily for 10 weeks increases muscle carnosine by 50% and 80%, after four and 10 weeks, respectively. This dosage regimen showed performance enhancements in an exhaustive cycling test, resulting in a 13% increase in total work after four weeks of supplementation and a further increase of 3.2% after 10 weeks, with no changes in the placebo group2. Additional studies have found that beta-alanine supplementation in doses of 3.2-6.4g per day can significantly attenuate fatigue during repeated bouts of sprinting4, improve sub-maximal cycle ergometry performance and time to exhaustion in young women5 and increase cycling capacity in young men6,7.

As noted by Roger Harris, Ph.D., professor of Sports, Exercise and Health Sciences at the University of Chichester, and a world-renowned sports nutrition scientist, beta-alanine should not be taken or made commercially available as a free powder. In this form, beta-alanine is very quickly absorbed and concentrated in the bloodstream, causing paraesthesia, a form of neuropathic pain. In addition, rapidly absorbed beta-alanine is quickly lost in the urine, if the blood concentration is high, limiting the amount retained in the muscle and available for the synthesis of carnosine. 

When formulating beta-alanine, Harris indicates it is likely that beta-alanine will react with aldehyde groups (such as those in simple sugars) over time. Therefore, it is important to test the stability of beta-alanine in bar and drink preparations that may be formulated for a longer shelflife. Beta-alanine already has been formulated into RTD preparations.



Caffeine

Caffeine is the most widely used, legal psychoactive agent worldwide. In doses of 4mg/kg, caffeine can increase mental alertness and improve logical reasoning, free recall and recognition memory tasks8. In addition to improving focus and alertness, caffeine can help increase time to exhaustion in endurance exercise bouts9,10, decrease ratings of perceived exertion during submaximal endurance exercise11,12 and improve physical performance during periods of sleep deprivation13.

Caffeine may also play an important role in recovery, by helping reduce muscle pain and soreness. Research shows that caffeine taken before moderate-intensity cycling has a dose-response effect on reducing leg pain during exercise14. For example, 5mg caffeine/kg bodyweight given one hour prior to high-intensity cycling exercise significantly reduces leg muscle pain during the exercise15, and 5mg caffeine/kg bodyweight given after eccentric exercise may decrease pain during subsequent maximal eccentric contractions16.

A recently published study found that the co-ingestion of caffeine (8mg/kg bodyweight) with carbohydrate (4g/kg bodyweight) after carbohydrate-depleting endurance exercise led to a significantly greater glycogen resynthesis (66%) than the ingestion of carbohydrate alone17. Hopefully, future studies will show that smaller doses of caffeine are effective, as well.  



EAAs/BCAAs, Waxy Maize Starch and Antioxidants

It is clear that both essential amino acids (EAAs, there are eight for adults) and branched-chain amino acids (BCAAs; there are three; the EAAs include all BCAAs) play pivotal roles in sports nutrition. EAAs increase muscle protein synthesis18,19,20,21 in a dose-dependent manner22. The BCAAs have been shown to decrease muscle protein breakdown22,23 and attenuate muscle damage and soreness associated with exercise22,23,24,25. An increasing number of studies are showing that leucine may be the key amino acid for increasing muscle protein synthesis (i.e., gaining muscle tissue), decreasing muscle protein breakdown and, as a bonus, leucine stimulates fatty acid oxidation29,30,31,32,33. EAAs and BCAAs can be formulated into bars, RTDs, powders, capsules and tablets.

Many companies are formulating products with waxy maize starch. However, there is no human clinical trial data indicating that waxy maize starch is an effective ergogenic aid. In a poster presented at the 2008 Experimental Biology Conference, Purdue University researchers compared a waxy maize starch to fast-digesting maltodextrin. Subjects consuming waxy maize showed a blunted insulin response and glucose response post-consumption, in comparison to maltodextrin34. The results of this study indicate that waxy maize may be better formulated in products aimed at blood sugar stabilization vs. sports nutrition.

Other potential ingredients in the recovery category include various antioxidants, especially anthocyanins. In vitro studies have shown that the concentration of anthocyanins found in approximately 20 cherries work as anti-inflammatory agents, blocking COX-1 and COX-2 enzymes35. One consumer products company, CherryPharm, produces cherry juice from tart cherries and has capitalized on the anti-inflammatory action of cherries. Their sponsored clinical research has shown their cherry juice, taken twice a day (12oz per bottle), may decrease the symptoms of eccentric exercise-induced muscle damage36. Antioxidant flavonoids may benefit connective tissue, by limiting inflammation and tissue degradation, improving local circulation and promoting a strong collagen matrix37.



L-carnitine L-tartrate

Carnitine has been around for years, but most studies examining the effects of supplemental carnitine on sports performance and fat loss have shown no benefit.  Why? Typically, supplemental carnitine does not make it into muscle (though studies have found that spiking insulin concurrently with carnitine supplementation does help transport carnitine into muscle tissue38. However, L-carnitine L-tartrate (LCLT) may hold promise as a sports nutrition ingredient. LCLT supplementation (equivalent to 2g of L-carnitine per day) for 21 days has been shown to significantly up-regulate resting androgen receptor content, suggesting an increase in cellular testosterone uptake39. Additionally, resistance-trained adults who supplemented with LCLT experienced significantly less muscle damage following an acute bout of resistance exercise40.



Whey and Other Protein Sources

Whey protein has one of the highest protein digestibility corrected amino acid scores (PDCAA)--a measure of both how well a protein is digested and how well it supplies the amino acids needed by an adult. Whey also contains one of the highest amounts of leucine, which may be the key amino acid for stimulating muscle hypertrophy, decreasing muscle breakdown and bolstering weight loss. In addition to the well-established role of whey protein in simulating muscle protein synthesis, whey also seems to boost weight loss. A recent study supported the results from a 2006 trial indicating that the addition of whey protein, with no other dietary modifications, helps boost weight loss for those engaging in a supervised resistance and endurance training program. In this particular 10-week study, subjects received a nutrition supplement containing 300 calories and 40g of protein once a day for two weeks and twice a day for the remaining eight weeks. After 10 weeks, the supplemented group saw significant decreases in total cholesterol and LDL (12.0% and 13.3%) and significant increases in muscle mass. Both groups showed a decrease in fat mass, but the exercise- and food-supplement group showed a significantly greater decrease in fat mass (-9.3% vs. -4.6% in the exercise-only group) 41.

In addition to those who are lactose-intolerant (many of whom many not realize that whey protein isolate is practically lactose-free), vegans and those who are allergic to milk proteins will opt for other protein sources.

Whey may have a superior PDCAA, but soy protein does increase muscle protein synthesis42 (though probably not to the same extent as whey). Egg, rice and hemp protein are additional choices.



Fenugreek, L-theanine and Phosphatedylserine

Though creatine, protein, BCAAs and EAAs have been the staples for building muscle, researchers at the University of Mary Hardin Baylor in Texas found that a highly purified, unique molecule extracted from fenugreek, the herb commonly formulated into products intended for weight loss or blood sugar control, may hold promise for boosting strength gains and altering body composition. In this double-blind study, 49 resistance-trained men, matched for fat-free mass, were randomly assigned to receive placebo capsules or 500mg of this fenugreek extract (FE). All subjects participated in a supervised four-day-per-week, periodized resistance-training program split into two upper (nine exercises) and two lower (seven exercises) extremity workouts per week, for a total of eight weeks. At the end of the eight-week period, the FE-supplemented group experienced a significant drop in body fat and an increase in both leg press and bench press strength, in comparison to placebo. This study indicates that 500mg FE had a significant effect on upper- and lower-body strength and body composition, in comparison to placebo. No significant side effects were noted. Colin Wilborn, Ph.D., the study’s principal investigator, noted that “though fenugreek has been marketed in dozens of dietary products claiming to have anabolic potential, this is the first study to directly examine what part of the fenugreek plant may hold promise for strength gains.”

Regular tea drinkers benefit from tea’s ability to help them maintain alertness, focused attention and accuracy, without overstimulation43. Both caffeine8 and the amino acid l-theanine44, naturally found in tea, stimulate areas of the brain that increase our alertness. In addition, l-theanine increases alpha-brain wave activity, which induces relaxation45. Studies show that l-theanine reduces psychological and physiological stress46, and it produces a dose-dependent relaxed, yet alert, state about 40 minutes after it is ingested. Most studies have used doses of 200mg23.

A recent study examined the effects of l-theanine (250mg) and caffeine (150mg) alone or in combination. Together, this combination led to faster simple reaction time, faster numeric working memory reaction time and improved sentence verification accuracy.  These results indicate a synergistic effect of l-theanine and caffeine47.

A few companies have already taken advantage of the science behind l-theanine and its GRAS status. For example, Glacéau created vitaminwater b-relaxed (jackfruit-guava flavor) with l-theanine to help the body deal with stress and promote relaxation.

Phosphatidylserine (PS) is a phospholipid that is present in cell membranes and plays a role in cell functioning. Most research has examined supplemental PS and memory and cognitive functioning. In relation to exercise, PS has been shown to attenuate physical48,49 and mental stress50. Doses used in sports studies range from 300-800mg51. A recent study showed that 200mg taken daily (in a food bar) for six weeks led to a tendency of improvement in perceived stress and statistically significant improvement in the number of good ball flights during tee-off52.

Supplements that enhance focus and concentration have been used by the military for years and recently promoted among golfers. But, many other athletes in a variety of sports would benefit from enhanced focus, while maintaining an alert state.

With so many research-based ingredients, a variety of packaging options and athletes who are hungry for the next best thing to help them workout harder, play better and recover more rapidly, the door is wide open for developing myriad sports nutrition products. By choosing a specific market (younger athletes, older athletes, professional athletes, military personnel, etc.) and product type, companies are more likely to achieve success. A product that works and tastes good will quickly catch on, not only in the sporting world, but often in the sport of life.  NS



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Sweet Energy Survey

The pace of introducing new energy products shows little signs of slacking. Mintel International’s GNPD records at least 16 U.S. products mentioning energy benefits launched in the relatively slow month of August this year. A recent Mintel report values the U.S. retail energy drink market at $4.8 billion, with growth over 400% from 2003. “‘Energy’ is a buzzword used by companies wishing to send a simple message to consumers for a complex concept,” says Lynn Dornblaser, director, Custom Solutions Group with Mintel International. “Energy could refer to mental, stamina or other physical benefits, for example. It is something of which consumers wish they had more.”

Indeed, “Prepared Foods’ 2007 R&D Trends Survey: Functional Foods” reported that 63% of food manufacturers said that “sustained energy release” was an important characteristic for an energy product to have; 49% said specialty ingredients that enhanced energy metabolism were; 47% said stimulants were important; and 44% said high amounts of quickly utilized energy sources, such as glucose, sucrose, maltodextrins and starches, were important in an energy product. Some of these latter ingredients provide desired sweetness, as well. Indeed, as the recently launched products show, there is little consistency among energy products in regards to ingredients used or, more specifically, in attitudes towards carbohydrates and sweeteners.

At one end of the spectrum, Sunbeam Bakers’ new Honey Grain Wheat Bread containing honey, high-fructose corn syrup and starches from grain notes that it offers “a bountiful supply of complex carbohydrates; a source of energy.” On the other hand, Promax Nutrition’s new Promax 70 High Energy Snack Bars notes it does not contain high-fructose corn syrup. Ingredients that do appear on its legend to provide both energy and sweetness include corn syrup, lactose-containing whey, fructose and sugar. In contrast, Mintel’s GNPD reports that new Life Fitness Rapid Energy Berry Fruit Chewing Gum by Advanced Healthcare Distributors claims to “help boost energy fast.” Its main components are vitamin B12, along with natural fruit and berry extract and the sweeteners xylitol and maltitol syrup. The company also just introduced a Taurine & B Vitamins Energy Drink under the Blade Energy brand, with a sugar-free claim and sucralose and acesulfame potassium as sweeteners. Western Family’s Complete nutritional drink, with 24 essential vitamins and minerals, notes it contains “carbohydrates to provide energy,” and lists corn syrup, maltodextrin and sugar (sucrose) high on its ingredient statement.

If such a survey of recent new products indicates anything, it is that there are no obvious ingredient choices when it comes to sweeteners and carbohydrates in products touting energy attributes.
—Claudia D. O’Donnell, Chief Editor



On the Web: SPORTS RESEARCH

* www.sportsnutritionsociety.org Website for the International Society of Sports Nutrition
* www.jissn.com The Journal of the International Society of Sports Nutrition (JISSN)