Yes, we should convert treadmills in gyms to produce power in addition to getting a workout. We need all the clean natural energy sources we can get. If there is a way to produce power while also getting a workout, then we should definitely be doing it. The motivation to work out would be great, too.
Treadmills could help provide some power to the gyms and reduce their dependence on the electrical grid. The same thing is true for all the other cardio equipment in the gym. It would not produce much power, but it could help and be an environmental friendly solution for gyms that use so much power.
Yes, treadmills should be converted. Since the individual would consenting to use the equipment, it would bring a benefit. It is also a great way to promote clean energy and a healthy lifestyle at the same time. I think people would be more inclined to work out and use the treadmill since they would be benefiting society even though it would be a small benefit. Since there are numerous gyms around the world, the impact collectively would bring about a positive change to the environment. In bigger gyms, it might cover the energy expenditures for lighting or any other services that use electricity, possibly bringing down the cost of a gym membership and enticing more people to improve their health.
The small amount of power that can be generated by a person walking on a treadmill is not worth the added expense required and the necessary maintenance. The process would create additional heat that would require even more energy to maintain a comfortable indoor temperature for people. The cost is not justified.