From 4-mile runs to 400-pound Deadlifts, every form of exercise damages your muscles. Your body uses the amino acids in protein to repair them and make them stronger—so both lanky centerfielders and husky left tackles can benefit from a little extra muscle dust.

“Our bodies are constantly turning over muscle tissue,” says Mike Nelson MS, CSCS. “Your body needs protein to build it back up.”

Protein powders are a quick and easy way to add more protein to your diet. Here’s a quick rundown of the four most common types.

Whey Protein

A byproduct of cheese production, whey is a fast-acting complete amino acid, absorbed into the muscles within 20 to 40 minutes of consumption. The most popular supplemental protein, whey comes in three forms: concentrate, the least expensive and most common; isolate, which is more processed and easier to mix; and hydrolysate, the most highly processed, which eases digestion but has a slightly bitter taste.

MuscleTech Nitro Tech – Strawberry

Calories: 140
Fat: 1.5g
Carbs: 1g
Protein: 30g

Casein Protein

Casein is the “other” dairy protein, a milk-based protein that, like whey, is a complete amino acid source. It is also high in calcium. Considered the “time-release” protein, casein is slower to absorb but harder to mix. Since it forms gels, it can be used to make protein muffins and other culinary creations.

Optimum Nutrition Gold Standard 100% Casein Cookies and Cream

Calories: 130
Fat: 1.5g
Carbs: 5g
Protein: 24g

Soy Protein

Soy offers the veggie-inclined an inexpensive plant-based protein source. However, unlike dairy or egg-based proteins, it does not contain all six essential amino acids, and it has to be fortified with thymine. Soybeans also contain phytoestrogens, which can increase estrogen levels in the body. Since more estrogen isn’t a great thing for all athletes (especially males), Nelson suggests alternating between soy, rice and buckwheat proteins.

GNC Pro Performance 100% Soy Isolate: Creamy Vanilla

Calories: 130
Fat: 1.5g
Carbs: 3g
Protein:  25g

Egg White Protein

This is what you get when you remove the protein fragment from an egg white, heat-treat it, and then dehydrate it down to a powder. Eggs are naturally rich in amino acids, making the powder a complete protein source and a good option for lactose intolerant athletes, who can’t use whey or casein. The mix might have a faint eggy taste, however.

Dymatize Nutrition Elite Egg Protein – Rich Chocolate

Calories: 110
Fats: 0g
Carbs: 3g
Protein: 24g