The best thing I know is going for a refreshing run in Kauppi Sports Park after a long day at work.
Kauppi Sports Park is a leisure park that is popular among local people. It is loved year-round for jogging, running and biking. My favorite path is called Kunto Kolmonen which is a 3 km loop in the woods. There are paths with different length and they are all well marked with wooden signs. The paths go alongside the lake Näsijärvi so you can take a stretching break on the shore. If you want to be adventurous and you have a curious mind, like I do, follow some of the smallest paths! You will surely find your way back since the forest is not so huge.
In addition to all the running possibilities, Kauppi Sports Park has football and baseball fields, tennis courts and greyhound tracks. In the wintertime, the park offers long cross-country skiing tracks for skiers.
Nothing beats the feeling after a decent workout, so why not enjoy that feeling while staying in Tampere!