We use the public code SteParKin to derive their galactic space velocities, which served us to locate them into the different galactic populations. We also identify candidate members in young stellar kinematic groups with SteParKin, LACEwING, and BANYAN Σ based on their kinematics. From the combination of kinematic assignments as a proxy of age and rotation-activity features, we define five rotation-activity-spectral type relations that M dwarfs under 800 Ma satisfy. We are then able to assess youth in this regime from the available data. We identify around 170 young (age < 800 Ma) M dwarfs in the solar neighbourhood, many of which have never been suggested before as young candidate stars. We also provide a list with 50 active M dwarfs and with the strongest surface magnetic fields among which there are 7 M dwarfs that are perhaps the youngest, most active, nearest M dwarfs observable from Calar Alto, with ages less than about 50 Ma.