The annual meeting of the International Society of Sports Nutrition was held during the first week of June 2008 at the $925 million Red Rock Casino and Spa in Las Vegas. The Red Rock, named for the nearby Red Rock Mountains, opened in 2006 and is located 10 miles away from the fabled Las Vegas Strip. I last attended the ISSN meeting two years ago, when it was held at the now-defunct Sahara Hotel on the Strip.
This year’s event looked promising, as it featured several well-known researchers in sports nutrition and exercise physiology. There were scheduling conflicts; I chose to attend the seminars that seemed likely to provide the most practical information for those engaged in bodybuilding.
Richard Kreider: Nutrition Strategies for Preventing Overtraining and Optimizing Performance
Kreider heads the sports nutrition lab at Baylor University in Texas and has published a number of studies analyzing the effects of popular sports supplements. Here are the highlights of his discussion:
• The best supplements for promoting lean mass gains with resistance training are protein supplements, essential amino acids, HMB and creatine.
• Protein requirements vary with level of exercise, but as a general rule, the following apply:
General fitness: .8 to 1 gram per kilogram of bodyweight
Moderate fitness: training 30 minutes to one hour, three to four times a week—1 to 1.5 grams per kilogram of bodyweight
Heavy training: training two to three hours, six days a week—1.5 to 2 grams per kilogram of bodyweight
Training at elevated altitude: 2 to 2.2 grams per kilogram of bodyweight.
• Most people engaged in bodybuilding need an average of 1.8 grams of protein per kilogram of bodyweight.
• Athletes who need to make weight are at the greatest risk of not getting enough protein due to decreased calorie intake. That includes runners, cyclists, swimmers, skaters and boxers. A high-quality protein supplement is valuable for them. Protein quality is based on the content of essential amino acids.
• The best overall supplement for increasing muscle, based on existing research, is creatine. It enhances muscle glycogen synthesis, increases work capacity and boosts exercise recovery. Studies have shown that using creatine supplements can double muscle gains when compared to a placebo. The gains are derived from more efficient muscle protein synthesis, not water retention.
• The optimal essential amino acid intake for increasing muscle mass is six grams.
• HMB is a leucine metabolite that in doses of three grams a day may help untrained people build muscle. The jury is still out on the effects of HMB in those with more training experience, although it may help prevent excessive muscle breakdown after intense training.
• Sodium bicarbonate—baking soda—may provide ergogenic effects if you take it one to two hours before competition at a dose of 0.3 grams per kilogram of bodyweight. Another method: taking 10 grams of sodium bicarb for five days. Sodium bicarb affects activity lasting one to three minutes. Since it can cause gastrointestinal distress, it’s best to start with small doses.
• Sodium phosphate, like sodium bicarb, may reduce excess extracellular acidity. Some studies show that it increases oxygen intake. The dose is four grams a day for three to six days.
• Beta-alanine shows promise as a precursor of carnosine synthesis in muscle. Taking four to six grams a day of this intramuscular buffer can increase muscle carnosine by 60 to 80 percent.
• GAKIC is an amino acid complex that when taken right before training may give you more reps during training.
• AAKG, an arginine complex taken in 12-gram doses, increases one-rep-maximum bench press strength. This form of arginine is common in many nitric oxide-boosting supplements.
• Branched-chain amino acids may have anticatabolic effects, but research is equivocal on the benefits. Leucine, one of the three branched-chain amino acids, is the primary amino involved in muscle protein synthesis, however.
• In summarizing his suggestions for athletes, Krieder recommended eating a high-carb diet, taking a multivitamin daily, carb loading, drinking plenty of water and fluids to prevent dehydration, and using posttraining and evening protein drinks.
Layne Norton: Optimizing Protein Intake for Muscle-Mass Gains
Norton is a graduate student from the University of Illinois who is also a bodybuilder. He’s been published in this magazine and elsewhere.
• Norton believes that specific meal recommendations are more important than total daily protein intake in relation to making muscle gains.
• Leucine is the primary initiator of muscle protein synthesis. Taking three to four grams of leucine per meal maximizes it.
• Twenty-five to 33 grams of whey protein contain three to four grams of leucine. You’d need to eat 54 grams of chicken or 20 slices of bread to get that amount of leucine.
• The notion of constantly supplying amino acids to build muscle is wrong, according to Norton. He cited studies showing that an infusion of amino acids for six hours led to an increase in muscle protein synthesis for only the first two hours. The activity stops after that time, even though plasma amino acids may still be elevated for five hours or more. When you eat a meal containing protein, fat and carbs, muscle protein synthesis lasts for at least three hours.
• Insulin also drops off after about three hours, so there must be a connection between insulin decline and decreased muscle protein synthesis.
• One study showed that taking 2.5 grams of leucine between meals increased muscle protein synthesis. Contrary to popular opinion, eating small, high-protein meals more often doesn’t give you the same result.
• It’s more effective to eat larger amounts of protein at each meal, separating the meals by four to six hours.
• Using an example of a 200-pound bodybuilder, Norton provided this model: five meals a day, each meal separated by four to six hours, four grams of leucine per meal, two meals from whey, two chicken meals, one beef meal. The whey meal must contain 33 grams of protein to maximize muscle protein synthesis. That would result in a daily intake of 225 grams of protein, close to the often suggested dose of one gram per pound of bodyweight. Taking essential amino acids between meals augments muscle protein synthesis.
• Younger people can eat less protein because they get increased insulin response. Older people need to take more essential aminos to duplicate the response of younger people.
• Whey is the preferred protein source because the slowly digested casein, another milk protein, won’t supply enough readily available leucine to maximize muscle protein synthesis.
• Eating fewer calories leads to greater use of protein as an energy source, as does endurance exercise.
Richard Bloomer: The Truth About NO Supplements
Bloomer is an assistant professor at the University of Memphis, and his research focuses on antioxidants and oxidative stress. He told me that he used to be a competitive bodybuilder and as a teenager went up against none other than two-time Mr. Olympia Jay Cutler (Cutler won). Perhaps for that reason Dr. Bloomer began his discussion by pointing out how large a role genetics plays in bodybuilding success. He suggested that about one in 10 million has the genes to duplicate the bodies you see competing in the Olympia.
His seminar focused on the efficacy of the popular nitric oxide supplements. Bloomer noted that none of the companies selling NO products seem willing to sponsor research to support the claims they make in their ads. On the other hand, if the products didn’t work at all, they would likely have fallen from favor. Other points he made:
• NO is a free radical and a gas with a short half-life. That means it disappears rapidly. The amount of NO is determined by the amount of nitrite in your blood.
• Low or slightly elevated amounts of NO have positive effects on health. Large amounts can be toxic because it reacts in the body with superoxide to form peroxynitrate, one of the most toxic free radicals. So products that promote excessive increases in NO aren’t a good thing.
• A low level of NO in the body is good for cardiovascular health. The vasodilation of blood vessels from NO release leads to lower blood pressure, greater oxygen delivery to muscles and improved nutrient delivery to tissues.
• While intravenous administration of arginine can boost NO in the body, there’s no evidence that any type of oral arginine supplement duplicates the effect.
• Exercise alone increases NO release after eight to 12 weeks.
• Many bodybuilders say that NO supplements work for them, but there could be another mechanism at work. Many NO products also contain simple sugars, which promote an insulin release, itself a cause of rapid vasodilation.
• Contrary to popular belief, arginine, though it’s the direct dietary precursor of NO synthesis, doesn’t regulate the process. What actually determine how much arginine gets converted into NO are the NO–synthesizing enzymes.
• A supplement that may boost NO an average of 18 percent above baseline is propionate L-carnitine and glycine, sold as GPLC, which boosts NO–synthesizing enzymes in the lining of blood vessels. You need 4.5 grams a day divided in two doses. It’s best taken in with a high-carb source, as the increased insulin release helps retain carnitine in muscle. If all that sounds familiar, it’s because I’ve written about that effect in previous issues of IRON MAN. Note that at current prices, using the suggested dose of GPLC isn’t cheap. On the other hand, it’s good for your heart, and it’s the preferred form of carnitine in muscle metabolism.
Darryn Willoughby: Protease Supplementation and Muscle Damage
Willoughby, also from Baylor University, specializes in how exercise and nutritional supplements regulate the molecular mechanisms of muscular growth. You can’t help trusting his information: He looks like a champion powerlifter or professional linebacker, not a geek who never set foot in a gym. Willoughby talked about using proteases, or protein-digesting enzymes, to improve muscle recovery and the molecular mechanisms of muscular inflammation. While there was a bit of biochemistry overload, the man does know his stuff. Among his many valuable points:
• There’s no direct relationship between the extent of muscle soreness and muscle damage following exercise.
• While protein-digesting enzymes, such as bromelain and papain, are most often linked to digestion of protein foods, when taken without food, they may have potent anti-inflammatory effects that help increase muscle recovery.
• Protease supplementation improves the return of interstitial fluid, or lymph, and cells to the blood, which reduces swelling and edema. Taking the enzymes without food also appears to decrease production of inflammatory prostaglandins and other eicosanoids.
• The inflammatory response is a result of tissue damage, usually from eccentric muscle contractions, which increases capillary permeability and allows leakage of proteins, such as fibrinogen, albumin and various globulins into the interstitial space—the lymph system—at the site of the injury. Fibrinogen is particularly important because it hinders the return of edema fluid to the capillaries and lymphatic channels. That leads to edema and inflammation in the affected area. Protease enzymes break down the fibrin barrier, thus giving you greater flow of lymph and decreasing inflammation. At least, that’s the theory. Willoughby pointed out that no one knows for certain how the enzymes work, since research in this area is just beginning.
• What is known is that an oral dose of about three grams of protease enzymes lessens strength losses, minimizes muscle damage and improves recovery. Previous studies of protease enzymes appear to have used a dose too small to show any effectiveness.
Stu Phillips: The Superiority of Whey Proteins for Building Muscle
Phillips, from McMaster University in Canada, is a well-known researcher specializing in skeletal protein metabolism. His discussion focused on why whey protein is best for building muscle. His essential points were:
• The timing of protein intake is more important than the amount of protein taken in.
• Whey is the highest-quality protein available because of its high BCAA and leucine content.
• Athletes have different needs for protein than nonathletes. Bodybuilders and strength athletes need 1.6 to 1.7 grams of protein per kilogram of bodyweight each day. Most athletes get at least 25 percent of their total calorie intake as protein, which meets their daily needs.
• Endurance athletes need more protein because they burn more energy, including protein. Also, endurance exercise shuts down muscle protein synthesis.
• There’s no tolerable upper limit for protein intake. The recommended daily allowance of 0.8 grams per kilogram of bodyweight was never intended to represent a target goal for protein intake.
• Hard-training athletes need more protein for remodeling of proteins in tendons, bones and ligaments. Protein supports gains in lean mass, optimal immune function and optimal use of plasma proteins.
• A study of older men compared the effects of taking protein immediately after exercise with waiting two hours after exercise to take it. The supplement used in the study contained only 10 to 12 grams of protein. Taking it right after training supported muscle protein synthesis, but delaying it by two hours abated that effect and blocked training-related strength increases.
• Taking more than 10 grams of protein leads to an increase in protein oxidation. The maximum amount of protein you can take in at a single time and avoid oxidation is 20 to 25 grams. Resistance exercise improves the ability to use protein, which explains why advanced trainees may need less protein than beginners.
• Various studies prove the superiority of milk over soy protein in supporting muscle protein synthesis after resistance training.
• In one study a subject taking protein gained seven kilograms of lean mass in 30 days, far more than other subjects in the same study. Phillips attributes that to more favorable responses due to genetic factors and suggests that this was the type of person who could add huge amounts of muscle and wind up as a professional bodybuilder.
• The BCAA leucine is not only the key to muscle protein synthesis but also stimulates significant bodyfat loss. The mechanism may be an upregulation in the activity of thermogenic proteins in muscle.
• Casein is the slowest digesting protein known, and no other food protein duplicates its effect. Cottage cheese is largely casein. While casein curdles in the stomach, leading to a slow release of protein, whey remains in solution, leading to a rapid uptake into the body.
This is only a small part of the information offered at the ISSN meeting, but it’s the material that I thought would have most relevance for IRON MAN readers. One final thing: The cliché “What happens in Vegas, stays in Vegas” was true in my case. I received a box lunch during the second day of the conference. Somehow I misplaced the box. So it did indeed stay in Vegas. IM