...{snip}...5 hours between flights doesn't really give you enough time to do anything as the airport is around 1 hour from the city and it's relatively expensive (€12 return by bus or €20 by metro) to get there.
It's 10 hours and 10 minutes between flights, not 5 hours. But unless OP is willing to invest €€€s for a long sleep at the Sofitel, spend the whole time at the airport will be worse than walking like a zombie in Athens
