External nitrogen pump works quite well. Nitrogen pump is the most popular tonic for fitness, which can help people improve their endurance and thus play an anti-fatigue role. If a small amount is taken, it has no effect on the body, but if it is taken too much at ordinary times, it may cause nausea, gastrointestinal discomfort, vomiting, muscle spasm and so on.

Fitness precautions:

(1) To do fitness exercises in winter, warm-up activities should be sufficient, especially outdoors. First, make full preparations for warm-up, and then carry out higher-intensity fitness exercises.

(2) The thickness of clothes should be suitable for winter fitness activities, and the head, back and feet should be kept warm. When you exercise outdoors, you should pay attention to keep warm. After exercise, don't stand in a windy place and blow. Go back indoors as soon as possible, dry your sweat and put on clean clothes.

(3) The environment should be clean and comfortable. When you exercise indoors, you must keep the indoor air circulating and fresh.

Refer to the above content: Baidu Encyclopedia-Nitrogen Pump