Individuals poststroke with gait and balance impairment are typically less active and have low levels of physical fitness. Improving fitness level while also improving gait and balance is very important. Maximizing the exercise training benefit requires the appropriate level of effort is achieved. Traditional exercise programs scale aerobic demand by increasing the walking speed or the slope of the treadmill surface. This may be difficult for individuals who experience decreased balance at faster speeds or on sloped surfaces and require the use of handrails to safely walk under these conditions. These exercise programs show limited improvement in walking ability after training. This project will test a novel approach, resistance-based treadmill walking, for maximizing improvements in fitness and ability to walk by individuals poststroke. The investigators previous research has shown that backward directed resistive force applied to the pelvis while walking is well tolerated by individuals poststroke. Further, these forces can be used to effectively scale aerobic demand while walking in a controlled manner. With traditional treadmill training approaches handrail support is utilized to ensure safety. However, handrail support externally stabilizes the individual reducing training improvements in walking capacity and balance. For this pilot investigation a group that aerobically trains using a standard exercise treadmill training paradigm will be compared to a group that experiences progressive backward directed resistive forces applied to an individuals' pelvis while they walk at comfortable walking speeds without the aid of handrails. Individuals will wear a fall harness that provides no external stabilization but prevents falls to the treadmill surface. This approach has the potential benefit of allowing individuals poststroke to meaningfully practice walking at safe speeds but against resistance thereby improving walking economy, dynamic balance, and walking speed. The proposed project is necessary to gather preliminary data for a much larger training study that has the potential to change the clinical approach for improving gait economy, balance, and walking speed for individuals poststroke.