My friend's milkshake cup has a strainer. P30 in Physical Growth and Physical Training says that protein powder must be fully shaken before intake. Professional shake cups generally have a filter screen to stimulate the active factors in protein powder. I don't know this, and I dare not comment. It's not broken anyway. Please rinse the cup with water as soon as possible after use and dry it in a well-ventilated place. Otherwise it will stink-if whey protein is concentrated, put water before powder, otherwise the powder will stick to the bottom. However, separating whey will not encounter the problem of sticking to the bottom. Generally, warm water or cold water is used to fill protein powder, which is definitely not ice water, and ice water is also quite insoluble. In addition, it is not suitable for drinking ice water after exercise, which has bad stimulation to the stomach. Water is usually 300cc, but I personally like to pack more because I need to replenish water after exercise. Glucose can be added to protein powder for drinking, so as to improve insulin level and promote protein absorption.