Yesterday, I shared some detailed information about how to train the anterior deltoid(please click Chapter 12). Now, I will focus on the middle deltoid exercise.
昨天为大家带来的是三角肌前束的动作（请点击 Chapter 12），那么今天接着为大家介绍三角肌中束的练习！
Dumbbell Lateral Raise 哑铃侧平举
In fact, you can obviously feel that different actions are finished by different parts of the muscles. Seen from the following picture, you can see that the middle deltoid provides the power.
Action tips: Use your hands to hold dumbbell naturally vertical in front of the body. At the same time, make your hands raise the dumbbell laterally. Your arms can not be completely straight. Maybe forming a 135-degree angle is a good choice. Try to use the power of the muscles to raise dumbbell, and form a 90-degree angle between arms and body.
ATTENTION: Do not shrug and shake the body. Complete 4 groups, each group for 12.
大家其实可以很明显地感觉到不同的动作受力的肌肉是不同的，那么如图，大家可以看出是肩膀中部在发力。
动作要领：双手握住哑铃自然垂直在身体侧方，同时向侧面平举，手臂不可完全伸直，呈135度最佳，运用肌肉力量提起哑铃，手臂与身体呈90度即可。
注意：不要耸肩借力，身体不要尽量晃动以免运用惯性借力。完成四组，每组12个。
Dumbbell Shoulder Press 哑铃肩上推举
This action can well increase the girth of the shoulders, which is mainly used to practice the middle deltoid muscle. You are expected to use heavier dumbbells to exercise.
Action tips: To finish this, you can sit or stand. But generally, stand when you are doing this part. When falling the dumbbell, make sure your upper arms are nearly at the same level with your shoulders. Try your best to push up the dumbbell.
ATEENTION: The weight varies from light to heavy. Complete 5 groups and in the last
two groups, you can keep doing until you are exhausted.
这个动作能很好地增加肩部的围度，主要练习三角肌中束，一般使用大重量练习。
动作要领：此动作可坐姿可站姿，一般使用站姿。落下时大臂几乎与肩呈一条直线，推举时尽量上举。
注意：重量从轻至重，完成五组，最后两组做到力竭。
PS: As the work is busy, writing articles and translating is time-consuming. Today I only introduced some ways to exercise middle deltoid. More details about posterior deltoid training and stretch will be given in tomorrow’s post. Hope you can understand. Thanks.
由于工作实在繁忙，写文章以及翻译又十分耗费精力，今天只为大家介绍三角肌中束的动作，明天将为大家带来后束和拉伸练习，望大家体谅！谢谢！