Abstract: A weight sled for fitness training that uses a plurality of resistance mechanisms to allow for adjustment of resistance. Depending on the configuration, wheel skid or slippage control may be provided by electronic monitoring of the angular velocity of one or more wheels and electronic adjustment of the resistance of any skidding or slipping wheels, bias correction and directional control may be provided by using a plurality of resistance mechanisms via differential adjustment of the resistance of the plurality of resistance mechanisms, and differential adjustment of the resistance mechanisms may be used to manually or automatically offset a directional bias in the sled, ground surface, or the athlete's abilities to keep the sled moving in a linear motion, and to prevent wheel skid on surfaces with differing friction coefficients.

Abstract: A weight sled that allows both linear and non-linear movements such that resistance training can be performed in the frontal, sagittal, and combined frontal/sagittal planes, and which allows easy movement for transportation, storage, and retrieval from storage. The weight sled uses one or more swiveling, pivoting, or omni-directional wheels that allow all or a portion of the sled to be moved laterally. The addition of wheel configurations allowing of lateral movement of all of, or a portion of, the weight sled greatly expands the utility of weight sleds because movement in any direction can be trained, whether in the sagittal body plane (forward/backward movements), the frontal body plane (lateral movements), or a combination of the two. Additionally, the plurality of wheel configurations allows for a variety of storage arrangements.

Abstract: A weight sled for fitness training that uses a plurality of separately-adjustable resistance mechanisms to allow for adjustment of overall resistance, bias correction and directional control, and wheel skid or slippage control, by means of differential adjustment of the resistance of the plurality of resistance mechanisms. Differential adjustment of the resistance mechanisms can be used to manually or automatically offset a directional bias in the sled, ground surface, or the athlete's abilities to keep the sled moving in a linear motion, and to prevent wheel skid on surfaces with differing friction coefficients.