A person's ecological footprint is the extent to which the actions of the person affects the environment.
Driving a car consumes petroleum based fuels and produces carbon dioxide. In addition, the production of the car also requires a lot of natural resources. The net result of all of these is an increase in the ecological footprint. A person can minimize this by using a car that has been produced in a way resulting in the least ecological impact, this could also include choosing electric cars or hybrids. The car should be well maintained to ensure a high efficiency. A car should also not be used for small distances that can easily be covered on foot.
Changing clothes daily is important as far as hygiene is concerned. But washing clothes daily also requires energy, water, cleaning agents, etc. that contribute to an increase in the ecological footprint. The same set of clothes can be worn more than once if they are not dirty.
Playing hockey could increase the ecological footprint if the ice on which the game is being played has been manufactured specifically for this purpose. Also, playing ice hockey when the weather is warm requires the consumption of energy to reduce temperature. An ecologically friendly way of doing things would be to play games that require the least wastage of natural resources. In summer, one can play baseball instead of ice hockey inside an indoor stadium.