Susan, 28 years old, is a marathon runner that weighs 130 lb. based on the protein recommendations from the american college of sports medicine for athletes, approximately how many grams of protein should she eat daily?

Susan should eat approximately 100 grams of proteins daily.

Explanation:

According to the Academy of Nutrition and Dietetics, Dietitians of Canada and the American College of Sports Medicine, athletes should eat 1.2 to 2.0 grams of protein per kilogram of body weight per day, the rate is depending of the type of exercise.

Based on the type of exercise she does, Susan needs 1.7 grams of protein per kilogram of body weight. She weigts 130 lbs which converted into kg are 58.96 kg approximately.

58.96*1.7=100.232 grams of protein daily

An optimal range of protein intake for an athlete trying to gain muscle is 1.5 to 1.8 grams per day per kilogram. If your goal is to maintain muscle mass, the range is 1.2 to 1.4 grams per kilo daily. So to calculate your needs, simply multiply your weight by one of the above figures, explains Chad Landers, a certified strength and conditioning coach who also has a diploma from the International Olympic Committee on Sports Nutrition.

It also recommends that you consume 20 to 30 grams of protein after your workout. Check the list of nutritional information of the products you consume.    

Whey protein acts faster, so it is more effective before and after workouts, but it is important to consume protein from a variety of sources (chicken, fish, lean meats, low-fat dairy products, nuts, beans and legumes) for optimal performance and to maintain health.

Some supplements also contain creatine, the quality can help increase muscle mass, and they are safe as long as there are no kidney problems. In addition, it is important to consume adequate amounts of carbohydrates, both before and after exercise, since it is the fuel that really drives the muscles. If you do not consume necessary carbohydrates, your body will have to use some of the proteins you eat as fuel, a much less efficient process that can prevent your muscle gain.