Protein Intake and Performance For Runners
Are you taking in enough protein? Too much? At the right times?
Matt Fitzgerald—Protein is the only macronutrient left with generally positive associations. Fat has been considered “bad” for decades. Whose idea was it to call it fat, anyway? That’s bad marketing. The truth is, there’s nothing inherently wrong with fat. It’s just that most of us eat too much of it, or too much of certain kinds of it.
Carbohydrate was generally regarded as a good nutrient until Robert Atkins came along and ruined it. The low-carb craze may be long gone, but Atkins casts a long shadow. The current popularity of the Paleo Diet among endurance athletes is very much an Atkins aftershock. The reputation of carbohydrate may never be fully rehabilitated.
This leaves protein, as I’ve suggested, as the lone unsullied macronutrient. This is ironic because humans require much less protein than they do carbs and fat, and protein consumption becomes “too much” at lower levels than carbohydrate and fat intake.
There are, of course, protein zealots out there who believe that more is better, with no point of diminishing returns. The notion that massive amounts of protein intake are required to maximize muscle size and strength is an article of faith among the weightlifting crowd. Science clearly shows otherwise. The muscle-bound actually require less protein than the average person because their bodies are so adept at retaining the gigantic protein reserves already inside their bodies.
According to the World Health Organization, humans need to get only 10 percent of their daily calories from protein to maintain health. There is reason to believe that runners may need more, however, because running breaks down muscle proteins and damages muscle fibers, and protein is needed for the muscles to recover from the daily onslaught of training. But a study of the diet of elite Kenyan runners found that they got only 10 percent of their daily calories from protein. Given their running performance, it would be difficult to argue that this wasn’t enough.
Such numbers are deceptive, though. It is more helpful to think of protein needs in terms of amounts of protein relative to body weight instead of protein as a percentage of daily calories. That’s because running increases total energy—carbohydrate, fat, and protein—needs. So you may get 10 percent of your daily calories as a non-runner and then continue to get 10 percent of your daily calories as a runner, but you’re eating more protein as a runner, because you’re eating more total calories.
So, how much protein do you need as an amount relative to your body weight? If you train lightly, 0.5 gram per pound of body weight should do; 0.8 gram per pound of body weight may be needed if you run a lot of miles.
You can eat substantially more protein without any harm, and with some potential benefits. Studies have shown that athletes trying to shed excess body fat do so more successfully on high-protein diets where 30 percent of daily calories come from protein, especially when weightlifting is added to the training mix. When calorie restriction is combined with increased protein intake and weightlifting, all weight loss is fat loss, whereas when calories are reduced alone, less fat is lost along with more lean body mass.
There is also some evidence that very high protein intakes help endurance athletes absorb heavy training loads. For example, a study at the University of Birmingham, England, found that cycling time trial performance was reduced less after a period of intensified training when cyclists increased their protein intake to 1.36 grams per pound of body weight at the start of that heavy training block instead of leaving it at 0.68 g/lb.
In short, there seems to be no magic sweet spot of protein intake that every runner has to hit on the nose every day. More important than the amount of protein consumed is the timing of protein intake. Numerous studies have demonstrated that exercise-induced muscle damage is reduced when protein is consumed immediately before and during workouts and that muscle repair proceeds most rapidly when protein is consumed immediately after workouts. You still don’t need a lot of protein, though. About 15 grams of protein per hour during exercise will suffice, while a total of 20 grams of protein in the first hour after exercise is as much as the body can use for immediate recovery.
About The Author:
Matt Fitzgerald is the author of numerous books, including Racing Weight: How To Get Lean For Peak Performance (VeloPress, 2012). He is also a Training Intelligence Specialist for PEAR Sports. To learn more about Matt visit www.mattfitzgerald.org.