Rule reminder
The gerund preceded by 'pur' (short form of 'pure') expresses a concessive meaning equivalent to 'sebbene' + subjunctive, but without repeating the subject. It is used when both clauses share the same subject. Present gerund: 'pur lavorando' (even though [he] is working). Past gerund: 'pur avendo studiato' (even though [he] had studied). This structure is common in formal written Italian.
Pur _____ stanco dopo la lunga giornata, Marco decise di uscire con gli amici.