While increased walking speeds are often key outcomes of poststroke rehabilitation, the success of poststroke locomotor training vary widely, and there is currently no consensus on the most effective method of poststroke gait rehabilitation. To improve the standard of care for poststroke rehabilitation, we propose the combination of novel, user-driven treadmill (UDTM) control and functional electrical simulation (FES) of the paretic ankle musculature. To examine the incremental effect of these elements, we determined the response of healthy adults to the UDTM control as well as the response of stroke survivors to UDTM control and FES. Since paretic anterior ground reaction forces (AGRF) and trailing limb angles (TLA) are key determinants of increased walking speed after stroke, we examined the walking speeds, AGRF, and TLA of individuals with each intervention element. Healthy adults increased their self-selected (SS) walking speeds by 0.14 m/s (p < 0.0001) and fastest comfortable (FAST) speeds by 0.19 m/s (p < 0.0001) instantly with UDTM control compared to fixed speed treadmill (FSTM) control. They achieve these speeds by increasing AGRF and TLA, which is promising for translation to poststroke training. With UDTM control and paretic limb FES, individuals poststroke instantly increased their SS speeds by 0.13 m/s (p = 0.0031) and FAST speeds by 0.12 m/s (p = 0.0001). They did so by increasing their AGRF and TLA bilaterally. By walking at FAST speeds with UDTM control and paretic limb FES, participants poststroke were able to increase their training speeds by 0.25 m/s on average compared to the FSTM control condition. Increased training speeds have been tied to improved function after rehabilitation, and a review of studies with treadmill-based training after stroke showed average changes in speed of only 0.06 m/s after 4 to 12 weeks of training. Since the instantaneous speed increases in this study are more than twice the average of long-term training, training with UDTM control and FES is a very promising option to improve poststroke rehabilitation. We expect this type of intervention would result in comparable if not greater gains in walking speed. Future work will examine the individual responses of participants to resolve the within-group variation as well as examine the carry over effects of multiple training sessions to optimize the prescription of UDTM control and paretic limb FES for poststroke gait training.