First of all, talk about their advantages and disadvantages. Sand is easy to leak and get into clothes and shoes, but it will be more comfortable to carry. Lead block is heavy and not easy to be damaged, but it is uncomfortable to carry. Iron ball is in between, I think it will be better. If you really can't buy something comfortable, you can make it yourself and use the ball, and the cost is not high.

Secondly, do you go to the gym, to gain muscle, or to thicken your legs? Do you eat while exercising, or do you always want to eat? There are many problems. In general, you are recommended to wear it for long-distance running and leapfrog. Wearing it every day is not good for your health, and you don't have to consider so much about the temporary belt, as long as you don't rub your feet and have the right weight.