In all these activities, weight is a factor that can be used to enhance strength and muscle tone. People in ancient Greece and China used weights for exercise much as we use them today. A number of Greek and Roman authors wrote about various types of weight-training techniques, some describing multiple methods that may not be applicable today. For example, Eratosthenes wrote about a type of weight training called "estronoming" which involved using weights as a means of self- punishment. In Europe, weights first appeared around 1500 B.C. and became popular among athletes and soldiers who needed strong muscles and bones. The Ancient Greeks and Romans had several terms for different kinds of weights: astynomoi (for use with handballs), dolichoi (for heavy objects), leukoi (light weights), mesogeios (middle-sized ones), perexeris (for pulling things). During the Middle Ages in Europe, weights were used primarily by soldiers and athletes to strengthen their arms and shoulders. As science began to evolve, so did weight training.