Matthew Kadey, M.S., R.D.—Like training for a marathon, dietary protein is not something to take lightly. Protein is essential for a wide range of bodily processes, most notably the synthesis and maintenance of muscles, enzymes, hormones, bones, cartilage, hair and skin. Plus, protein helps dull hunger, preventing surreptitious midnight fridge raids, and provides an auxiliary fuel source for runners to be used alongside fat and carbohydrate.
So, if all you focus on is carbohydrates, your body won’t function to its full potential. Yet, there remains considerable confusion about protein, which may leave you with no idea how best to approach this macronutrient. Let’s set the record straight.
Myth #1: Only Bodybuilders Need More Protein
To encourage recovery of mile-ravaged muscle, improve strength, help meet increased caloric requirements, and offset protein oxidation during bouts of running, runners undeniably require more dietary protein than someone who only runs to the fridge during halftime. Those undergoing endurance training need about 0.55 to 0.65 grams of protein per pound of body weight. So a 160-pound runner needs to eat roughly 88 to 104 grams of protein per day to meet training needs.
As intensity, frequency and duration of training increases, shoot for the higher end of the protein range. Skimp on this, and your body will borrow from muscle to meet its needs—undermining fitness growth. Fortunately, you should have no trouble meeting your protein quota if you nosh on a varied, whole-food diet (See "Protein Power" at the bottom of this article).
Myth #2: Protein Plays No Role In Replacing Spent Carbohydrate Stores
The power of protein post-exercise doesn’t stop with building lean body mass. Studies have demonstrated that consuming a combination of carbohydrates and protein early during the post-workout period enhances muscular glycogen levels (the storage form of carbohydrate) above what is incurred if only carbohydrates are sent down the gullet.
It’s believed that protein stimulates a larger rise in insulin levels, which helps drive more sugar into muscle cells to build more glycogen. Having saturated glycogen stores is vital to running performance, since this is the primary fuel used for high-intensity exercise. Studies suggest that the ideal ratio of carbs and protein in a post-exercise meal is roughly 4:1. So, after a hard run, top that plate of pasta with some meat sauce.
Myth #3: Only Protein From Animals Is Complete
The protein that is found in a hunk of steak is made up of a chain of amino acids, 12 of which can be manufactured by the human body. Another nine, called “essential amino acids,” must be obtained from food because the body is unable to make them from other substances. A complete protein is a protein source that contains all of the essential amino acids and does a better job at repairing and building muscle cells damaged through exercise than an incomplete protein source, which lacks one or more of the key amino acids.
Steak lovers like to trumpet protein from animal sources such as beef, chicken, eggs and milk as the only real way to get enough complete protein to meet muscular needs. But on top of providing serious nutritional firepower, the plant foods soy, quinoa, hemp, spirulina, chia and amaranth do contain a full complement of amino acids, making them a worthy addition to any post-run repast.
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Plant foods that are incomplete and need a little help, such as brown rice, beans, nuts and lentils, can be paired together at a meal to form complete proteins. Examples are beans and rice, lentils and corn, and nut butter on whole-grain bread. Whether you are a vegan or meatarian, as long as you consume a varied diet you should have no problem consuming enough high-quality protein to meet your training needs.
Myth #4: Protein ‘Megadosing’ Maximizes Muscular Benefit
A watershed study in the Journal of the American Dietetic Association determined that the ingestion of more than 30 grams of protein (about 113 grams of lean beef) in a single meal does not further boost the stimulation of muscle protein synthesis in both young and elderly persons. Excess protein will be lost to oxidation (at the expense of fat stores) or potentially converted to fat stores.
Yes, like carbohydrates, too much protein can pad your midriff with doughy flesh. The upshot is that it’s wise to spread protein intake throughout the day to maximize muscle repair and synthesis instead of loading up during one or two meals.
Myth #5: Protein Powders Are A Must-Have Supplement For Athletes
Those tubs of protein powder do have their merits, particularly fast-digesting whey, which has a very high protein quality score, but it’s very much possible for runners to meet their increased protein requirements from food alone.
For example, a post-run smoothie that contains a half-cup Greek yogurt, 1 cup fat-free milk and two tablespoons peanut butter without any powder supplement has about 25 grams of protein. According to a 2009 study in the American Journal of Clinical Nutrition, 20 grams of protein post-workout is the magic number to stimulate muscle recovery and synthesis.
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Here’s the grub that can help a 160-pound runner get enough protein during one day.
2 hard-boiled eggs
Protein: 12 grams
6 ounces Atlantic salmon
Protein: 34 grams
1 cup cooked quinoa
Protein: 8 grams
1 cup cooked lentils
Protein: 18 grams
1 ounce almonds
Protein: 6 grams
1/2 cup low-fat cottage cheese
Protein: 14 grams
1 cup fat-free milk
Protein: 8 grams
1 cup cooked oatmeal
Protein: 6 grams
Total Protein: 106 grams