Smart Nutrition Can Enhance Muscle Strength

“I’d like to gain a little muscle.”

“More muscle, hmm…, that would be good,” I agreed with the voice, and turned to find a male runner by my side.

“Aren’t you that sports dietitian?” he asked, unsure of whether or not to intrude on my post-race retreat into solitude. We begin to talk about nutrition. More strength sounded good to me right then as well, thinking of those painful climbs.

“Yes,” I answered him. “Nutrition can definitely help build muscle.”

Consistency Is Important

Gaining muscle strength starts with a consistent training plan. A regular schedule will help an athlete develop an eating routine and avoid a “grab and go” diet that is not likely to maximize training efforts. A pattern of eat, exercise, eat, rest is the best bet for building stronger muscles. Here’s how it works.

Step 1: Eat

For the body to be efficient at building muscle, a ready supply of amino acids must be available during exercise. Research has shown that L-arginine, which is a conditionally essential amino acid, stimulates the production of nitrous oxide. Nitrous oxide causes blood vessels to relax, allowing for increased blood flow. The delivery of available amino acids is enhanced by L-arginine just when the demand is greatest: during exercise. That’s why it’s important to eat a light balanced meal before exercise, including carbohydrate and protein.

In a hurry to get to the gym? Try using a balanced sport nutrition product like the all-natural protein CLIF Builder’s bar. It provides 20 grams of protein, primarily from soy, which is a rich source of L-arginine. Nuts and seeds blended with the soy provide a balance of amino acids. Packaged with a little carb, it’s a quick, nutritious choice for a muscle building workout.

Step 2: Exercise

I defer to the exercise physiologists and coaches to devise an effective exercise plan aimed at building muscle. But exercise you must, because it is the stimulus for your muscles to start building more protein. Studies where extra protein was given to sedentary individuals have demonstrated that protein is simply oxidized for fuel, or stored as fat. No pain, no gain.

Step 3: Eat

During exercise, muscle synthesis of protein is depressed. Exercise, like trauma or illness, is a stress to the body. Protein stores from the muscle are being tapped to supply amino acids for energy, enzymes, and various precursors to form hormones and neurotransmitters. So, during exercise, the body typically puts protein building on hold.

After exercise is catch-up time. Now the pump has been primed and muscles are screaming for amino acids, and a reboot of glycogen stores. Right after a work-out is the time to eat.

Step 4: Rest

Rest allows the body to produce more growth hormone, which, as its name implies, stimulates muscle growth. Rest also allows time for replenishing glycogen stores so that there is energy to burn for tomorrow’s workout.

Diet Specifics: How Much, What Type?

Obviously, you need to eat some protein to build muscle. But how much, what type, and combining it with other foods all affects how successful you will be in your building muscle endeavor. Let’s start with the first problem: how much?

Protein Builds in the Flame of Carbohydrate

Protein recommendations for an athlete are linked to total energy demands. Maintaining a steady glucose (carbohydrate) supply for the brain is the body’s top priority. During periods of starvation or prolonged energy deficit induced by training, protein stores in the muscle will be tapped for energy and muscle breakdown occurs. Providing extra protein in the face of caloric deficit will help to reduce muscle loss, but it will still occur. So if you can’t eat enough to maintain a stable weight during training, don’t expect that a 10-oz steak at dinner will build up your muscles. If your total calorie intake is too low, that steak will never show up on your biceps.

Strength training relies on anaerobic (i.e. without oxygen) metabolism for an energy source. Glycogen stores in the muscle provide a ready supply of carbo’s for anaerobic exercise. But there’s another reason to be concerned about carbs. Following exercise, carbohydrate is needed to raise the level of insulin, which is depressed during exercise. Without the presence of the hormone insulin, the uptake of amino acids into the muscle is very limited. No carb, no insulin, no protein assembled. Starting to get the picture?

Research has shown that the most effective way to maximize amino acid uptake is to eat a high glycemic index carb combined with protein. To be more specific, 35 g of high glycemic index carb combined with 6 g of protein seems to maximize delivery of amino acids to the muscle. In table terms, that’s about 20 ounces of a typical sport hydration drink, and 1 ounce of mozzarella string cheese. For best results, eat within one hour of working out.

Calculating Protein Needs

Research done on strength athletes indicates the upper limit for protein intake is 2.4 g/kg body weight. Going over that amount per kg does not further protein synthesis. Instead, the surplus protein undergoes oxidation and is stored as fat or used for energy. The maximum amount of protein recommended for adult athletes is 2 g/kg body weight or 136 g protein per day (150#/2.2 kg = 68 kg body wt.).

What Kind of Protein

Whey vs. soy seems to be the popular face-off in muscle building advertisements. Is one superior over the other? The latest nutrition research suggests that each has its own particular benefits: soy contains high levels of L-arginine amino acid, and seems to provide a richer source of antioxidants. However, in terms of gaining strength, both types of protein sources allow the body to build muscle.

Epidemiological studies, where populations are followed for years at a time to evaluate the effects of diet, suggest that for overall health a diet high in plant proteins is desirable. Lean sources of meat are superior to plant proteins in providing essential minerals such as iron and zinc. For most athletes, a variety of protein sources is recommended for overall health reasons.

Written by Donna Marlor, MA, BSN, RD


Journal of Nutrition 3: 22. Soy versus whey protein bars: Effects on exercise training and on lean body mass and antioxidant status.

Journal of Nutrition 134 (Oct.): 2894S. Potential ergogenic effects of arginine and creatine supplementation.