Treadmill is a common fitness equipment, and you can also do aerobic exercise at home. However, when using the treadmill, there may be situations where the speed cannot be adjusted. At this time, you should try the following methods to solve it.

1. Check whether the power supply is normal: the treadmill needs to be connected to the power supply to run. If the power supply is abnormal, the speed regulation function of the treadmill will not work normally. So check whether the power supply is plugged in and ensure that the socket works normally.

2. Check whether the wires are damaged: the wires of the treadmill are connected to the socket and the machine. After long-term use, the wires may be worn or loose, which will affect the use of the treadmill. It is necessary to check whether the interface of the wire is intact and ensure that the wire is not damaged.

3. Restart the machine: Sometimes, the running machine will break down, such as the speed can't be adjusted. At this time, you can try to restart the machine and check whether the handle is normal, loose and can accept instructions.

4. Replace the controller battery: The controller battery is a key component to control the speed of the treadmill. If the battery is exhausted, the controller will not work normally. The battery can be replaced to repair the failure of the treadmill.

5. Seek professional help: If none of the above methods can solve the problem, you may need to seek professional help. You can contact the after-sales service center or technical support personnel of the treadmill for testing and maintenance.

Generally speaking, it is necessary to find out the reason and treat the problem that the speed of the treadmill cannot be adjusted. If the above methods can't be solved, we should seek the help of professionals to ensure the normal use of the treadmill. At the same time, in order to avoid such failures, the treadmill should be maintained frequently.