Muscle Science Roundup

Believe it or not, we’re moving into 2010. Seems like just yesterday we were stockpiling food and weapons for the Y2K crisis that never happened. Thank the gods because who can train for Olympian mass and cuts in a secluded basement—okay, Dorian Yates, but he’s a special case. To help you carve your own freak physique, here’s a look at the key recent research studies that can help you build your mass and muscularity. So fasten your lifting belts and prepare to grow! [Note: Most of the following were provided by IRON MAN research scientist Jerry Brainum.]

1) Better Nitric Oxide Booster

Richard Bloomer is an assistant professor at the University of Memphis, and his research focuses on antioxidants and oxidative stress. 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). Bloomer has recently been studying the effectiveness of the popular nitric oxide supplements. One of his controversial findings is that 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 appears to 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 into two doses. It’s best taken with a high-carb source, as the increased insulin release helps muscle retain carnitine.

Note that, at current prices, using the suggested dose of GPLC isn’t cheap. On the other hand, the supplement is good for your heart, and it’s the preferred form of carnitine in muscle metabolism.

2) Protein Facts for Faster Muscle Growth

Stu Phillips, of McMaster University in Canada, is a well-known researcher specializing in skeletal protein metabolism. His latest research focused on whey protein and what timing and amounts are best for building muscle. Here are some of his key findings:

• Whey is the highest-quality protein available because of its high leucine and overall BCAA content.

• Athletes have different needs for protein from 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.

• 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.

• Leucine not only is 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.

3) Less Stress With PS—and More Testosterone and Muscle

A recent study confirmed the cortisol-blocking effects of phosphatidylserine and also found that using 600 milligrams a day for 10 days favorably affected the testosterone-to-cortisol ratio. While PS didn’t directly increase testosterone concentration, it did prevent the depletion of testosterone that usually occurs when lots of cortisol is released. Cortisol prevents both the synthesis and release of testosterone in the body, and the authors suggest that phosphatidylserine may help prevent overtraining. The researchers also found that the greater the exercise intensity, the more effective phosphatidylserine is in blunting cortisol’s impact. It did not appear to affect growth hormone, however.

Starks, M.S., et al. (2008). The effects of phosphatidylserine on endocrine response to moderate intensity exercise. J Int Soc Sports Nutr. 5:11.

4) Optimal Cardio to Rip and Grow

According to Jacob M. Wilson, M.S., CSCS, and Gabriel J. Wilson, M.S., CSCS, when you perform an HIIT session, meaning interval cardio such as sprinting the straightaways and walking the curves on a running track, several fat-metabolizing hormones increase. The problem is that at the same time the nervous system decreases the diameter of the blood vessels that carry blood to your bodyfat, so you don’t get the benefit of a lot of fat metabolism during the session. Immediately after the high-intensity session, when intensity is lowered, however, blood flow returns to fat tissue at a high rate, meaning epinephrine and norepinephrine have a chance to work their magic on fat cells.

The best formula appears to be to perform 10 to 20 minutes of HIIT cardio to raise the secretion of hormones known to stimulate the breakdown of fat, followed by 30 to 40 minutes of moderate-intensity cardio, during which the body can maximally use the fatty acids for fuel. Studies clearly demonstrate that traditional cardio burns more fat when it’s done following high-intensity exercise than when it’s done alone. One study found that both the actual energy cost and rate of fat metabolism of moderate-intensity running were higher when it was performed following interval training. Another indicated that performing moderate-intensity cardio after resistance training resulted in maximum fat burning during the cardio session. Note that it’s important to perform the moderate-intensity cardio immediately after your high-intensity workout, as the metabolic effects are short lived and quickly dissipate.

James, D.V., and Doust, J.H. (1998). Oxygen uptake during moderate intensity running: Response following a single bout of interval training. Eur J Appl Physiol Occup Physiol. 77(6):551-555.

Goto, K., et al. (2007). Effects of resistance exercise on lipolysis during subsequent submaximal exercise. Med Sci Sports Exerc. 39(2):308-315.

5) Active Recovery Between Sets for More Size and Strength

According to Jacob M. Wilson, M.S., CSCS, and Gabriel J. Wilson, M.S., CSCS, in order to optimize performance on each set, you should maximize lactic acid clearance. The most effective way to do that is through aerobic metabolism, providing ample oxygen to the muscles so they can clear lactic acid from the blood.

The most effective way to accomplish that, according to studies, is with low-intensity exercise—30 to 40 percent of your VO2 max. Exceeding that intensity risks crossing your lactate threshold and actually producing more lactic acid. Lower intensity will minimize oxygen delivery to the muscles. So if you feel a deep burn in your muscles during active recovery, you likely need to reduce your intensity.

The effectiveness of active recovery over passive recovery between sets has been demonstrated in sprinters and weightlifters, among other athletes. An excellent example was an experiment reported in the Journal of Strength and Conditioning Research. Fifteen experienced resistance-trained males performed weight workouts consisting of six sets of parallel squats at 85 percent of their 10-repetition maximums. The participants recovered for four minutes between sets with either passive sitting or low-intensity exercise on a stationary bicycle. After that workout participants performed a maximal-repetition-squat test using 65 percent of their 10-rep maximums. Those engaging in active recovery were able to do 20 percent more repetitions than the athletes who engaged in passive recovery between sets.

Hultman, E., and Sahlin, K. (1980). Acid-base balance during exercise. Exerc Sport Sci Rev. 8:41-128.

Hogan, M.C., et al. (1995). Increased [lactate] in working dog muscle reduces tension development independent of pH. Med Sci Sports Exerc. 27(3):371-377.

6) Beta-Alanine: Muscular Fountain of Youth?

When given to young adults, age range 18 to 30, at a dose of 6.4 grams daily for 28 days, beta-alanine increased work capacity before fatigue by 12 to 15 percent. What about older people? Would carnosine, which beta-alanine is a precursor of, reduce muscle fatigue for them too? Many older people don’t eat a lot of the richest natural source of carnosine, red meat. That said, enzymes rapidly degrade most of the carnosine from food—which does liberate some beta-alanine in the body. Nonetheless, one study of older people found that their type 2 muscle fibers—where carnosine concentrates, since they’re highly prone to increased acid production—contained 47 percent less carnosine than those of younger people.

More carnosine in older people would lower the muscle-fatigue threshold, making exercise easier and more effective. In a recent study researchers gave 800 milligrams of beta-alanine—less than what is usually supplied to younger people—three times a day for 90 days to 26 men and women, aged 55 to 92. Others received a placebo. The exercise was done on a special type of stationary cycle. Those in the beta-alanine group were able to exercise 28.6 percent more intensely before becoming fatigued. Those in the placebo group showed no changes.

While bodybuilders and other athletes show increased muscle carnosine from the exercise alone, the subjects in this study were untrained, thus pointing to beta-alanine supplementation as the source of their increased resistance to fatigue. The implication is that beta-alanine is particularly useful for older people, since it makes it easier for them to engage in exercise. Exercise, in turn, helps maintain physical and mental health and prevents the muscle frailty that is often the harbinger of mortality.

Stout, J., et al. (2008). The effect of beta-alanine supplementation on neuromuscular fatigue in elderly (55-92 years): A double-blind study. J Int Soc Sports Nutr. 5:21.

7) Supplement Combo to Grow On

Given the demonstrated ergogenic effectiveness of conjugated linoleic acid, whey and creatine, researchers postulated that combining all three would be more effective than taking any of them alone. They were also watching for potential health risks of using the supplements, such as increased oxidative stress, negative effects on bone mass and undesirable changes in kidney function. Both increased protein intake and creatine use have been implicated in adverse changes in kidney function, although that’s more speculation than fact, as measured by studies on the subject.

Some research suggests that conjugated linoleic acid may cause oxidative stress. Indeed, some human studies have found paradoxical side effects from CLA use, such as increased insulin resistance in men who have a lot of abdominal fat—itself a primary cause of insulin resistance. On the other hand, those studies mostly involved sedentary, nonexercising subjects.

This study found that those taking all three supplements experienced more gains in bench press and leg press strength, along with lean tissue gains, than the other groups combined. The groups taking creatine gained more lean mass than those who took only whey protein. Previous research showed that CLA produced greater gains in bench press strength in men but no effect on leg press strength and also no effect in women. While the precise mechanism of how CLA can influence muscle gains isn’t clearly established, one plausible hypothesis is that it reduces the inflammatory cytokines that produce muscle catabolism, such as tissue necrosis factor-A, a signaling agent in the loss of muscle. It’s a primary suspect in the loss of muscle with age, as its levels increase in the elderly. CLA didn’t produce any changes in fat mass in this study, although previous studies showed that it’s more effective in those who have more initial bodyfat. It doesn’t do much for people who are already lean.

Both CLA and creatine have been found to provide anticatabolic effects in muscle, and the combination of the two used in this study confirmed that. No increased oxidative stress or apparent negative effects on kidney function occurred in this study. The authors suggest that the combination of creatine, CLA and whey protein spurs gains in lean mass and strength for those engaged in resistance exercise and bodybuilding.

Cornish, S.M., et al. (2009). Conjugated linoleic acid combined with creatine monohydrate and whey protein supplementation during strength training. Int J Sports Nutr Exerc Metabol. 19:79-96. IM