There are a number of things that may be causing your issues and they may vary depending on the brand or model you have.
If you have no power at the console after the unit runs and then quits, you may have a problem with the incoming power source or a circuit breaker or the console itself. If the display stays lit as normal but the treadmill stops responding then there may be a problem with a speed sensor or the motor controller.
I would start with checking the wiring to be sure there are no loose connections or burnt areas indicating a short. If the console is battery powered, be sure that the batteries are fresh and at full power and making a good connection. If the unit plugs in, try a different wall outlet, preferably in another room altogether, to eliminate the possibility of a problem there.
Unfortunately, your question and Manage My Home profile provided no model information so it is difficult for me to provide any more specific information. But, if none of these basics help, some technically involved troubleshooting will be needed anyway so you may want to consider having the treadmill inspected by a professional.