Background: Stroke is the leading cause of long-term disability, and the second leading cause of death in the western world. Most stroke survivors will suffer from motor and cognitive disturbances for the rest of their life, which negatively affects their normal daily life. Despite the decline in stroke-related mortality over the past decades, the outcome of rehabilitation programs does not improve, and is predictable regardless of the program used. Still, several human and animal studies show that high capacity of training in the early stages post stroke improve motor recovery. This notion is far from being well established. Aim: Studying the effect of high-dosage, high-intensity training program in the subacute period on upper extremity motor recovery. Population: Stroke survivors. Study duration: 6 months. Study protocol: Participants will receive additional technology-based upper extremity training for 120 min/day, 5d/w, 4 weeks. They will be monitored pre and post training, and 6 months post-stroke. Outcome measures will include clinical, kinematic and adherence measures (see complete list in the protocol).