 According to the rules of the International Skating Union, a standard track should be either 400 m or 333⅓ m long; 400 m is the standard used for all major competitions.Tracks of other, non-standard lengths, such 200 or 250 m, are also in use in some places for training and/or smaller local competitions.On standard tracks, the curves have a radius of 25–26 m in the inner lane, and each lane is 3–4 m wide.