Whether you are training for Olympic weightlifting or interested in physical fitness, you have probably seen and used free weights. Barbells and dumbbells are well known free weights used for strength training.
Modeled after the athletic activity of ancient Egypt and Greece, the first worldwide competition of the modern sport of weightlifting was in London in 1891, 5 years before the first modern Olympic Games took place.
Modern barbells are made of a steel bar with rubber-coated disks of different weights, which are secured with the help of collars. Dumbbells are usually of a preset weight, but adjustable weight dumbbells are becoming more commonplace. They are usually made of cast iron or steel, although they are coated with vinyl or other materials to protect surfaces.
Iron ore, pig iron, and steel are produced in the United States. Iron ore for the most part is mined in Michigan and Minnesota. Raw steel and pig iron are mainly produced in Indiana, Ohio, Michigan, and Pennsylvania. The leading producers of iron ore in the world are Australia, Brazil, and China. The leading producers of steel and pig iron in the world are China, the European Union, Japan, and the United States.
- International Weightlifting Federation, 2001. Weightlifting history.
- USGS, 2006. Minerals Statistics and Information. United States Geological Survey.
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